The neodymium electrolysis produces unnecessary high emission of CF4 and C2F6. These perfluorocarbons (PFCs) are potent greenhouse gases and are not filtered or destroyed in the off-gas. A process control in analogy t...The neodymium electrolysis produces unnecessary high emission of CF4 and C2F6. These perfluorocarbons (PFCs) are potent greenhouse gases and are not filtered or destroyed in the off-gas. A process control in analogy to the aluminum electrolysis can reduce the PFC emission to a great extend and keep the process in a green process window. Therefore, a theoretical analysis is done of the cell voltage of the industrial neodymium electrolysis in dependence on the neodymium oxide concentration in the electrolyte. The analysis shows the different contributions to the cell voltage focusing on the impact of the anodic overvoltage on the cell voltage, by which the electrolysis process can be controlled. The model of the cell voltage is evaluated by laboratory neodymium electrolysis with a similar setup as the industrial cell. The relation of the oxide concentration, the anodic current density and the cell voltage with the cell resistance are measured. The continuous off-gas measurements show the gas concentration and PFC emissions. The effect of Nd2O3 feeding on the galvanostatic electrolysis is analyzed as well. Based on the results a process control strategy is proposed similar to the aluminum electrolysis strategy. The green process window is in a narrow oxide concentration range, making a continuous and precise oxide feeding essential.展开更多
Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,per...Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.展开更多
Pulsed dynamic electrolysis(PDE),driven by renewable energy,has emerged as an innovative electrocatalytic conversion method,demonstrating significant potential in addressing global energy challenges and promoting sust...Pulsed dynamic electrolysis(PDE),driven by renewable energy,has emerged as an innovative electrocatalytic conversion method,demonstrating significant potential in addressing global energy challenges and promoting sustainable development.Despite significant progress in various electrochemical systems,the regulatory mechanisms of PDE in energy and mass transfer and the lifespan extension of electrolysis systems,particularly in water electrolysis(WE)for hydrogen production,remain insufficiently explored.Therefore,there is an urgent need for a deeper understanding of the unique contributions of PDE in mass transfer enhancement,microenvironment regulation,and hydrogen production optimization,aiming to achieve low-energy consumption,high catalytic activity,and long-term stability in the generation of target products.Here,this review critically examines the microenvironmental effects of PDE on energy and mass transfer,the electrode degradation mechanisms in the lifespan extension of electrolysis systems,and the key factors in enhancing WE for hydrogen production,providing a comprehensive summary of current research progress.The review focuses on the complex regulatory mechanisms of frequency,duty cycle,amplitude,and other factors in hydrogen evolution reaction(HER)performance within PDE strategies,revealing the interrelationships among them.Finally,the potential future directions and challenges for transitioning from laboratory studies to industrial applications are proposed.展开更多
Water-cooled system have significantly enhanced the power generation efficiency of offshore wind turbines.However,these innovative systems are susceptible to substantial biological fouling,maintenance challenges,and h...Water-cooled system have significantly enhanced the power generation efficiency of offshore wind turbines.However,these innovative systems are susceptible to substantial biological fouling,maintenance challenges,and high upkeep costs.Therefore,the development of a specialized front-end filter tailored for direct current water-cooled system is importance.This involves the integration of dimensionally stable anode(DSA)and nickel alloy cathode,valued for their corrosion resistance in seawater,into a novel front-end filter system for Water-cooled applications.This system has the dual capability of generating hydrogen and chlorine for self-cleaning purposes.Implementing a flushing pulse electrolysis mode,it effectively mitigates electrode failure induced by cathodic calcium and magnesium deposition,thereby significantly prolonging electrode lifespan.Laboratory tests comprising system assembly and performance evaluations were conducted,with the system programmed to operate for 5 minutes every 24 hours under continuous flushing by natural seawater to simulate real-world conditions.After more than 11 months of continuous flushing,observations reveal that the DSA mesh and nickel alloy mesh maintain intact structural integrity and normal functioning.Subsequent 1꞉1 physical prototype Sea trial further validated the soundness of the system design and electrolytic control parameters.展开更多
The design and fabrication of ordered epitaxial MOF-on-MOF heterostructures as highly efficient electrocatalysts for water splitting is crucial but still challenging.In this study,a simple coordination-driven self-ass...The design and fabrication of ordered epitaxial MOF-on-MOF heterostructures as highly efficient electrocatalysts for water splitting is crucial but still challenging.In this study,a simple coordination-driven self-assembly method is used to fabricate controllable MOF-on-MOF multiscale heterostructures,where triangular host MOF(ZIF-67)nanosheets undergo in situ epitaxial growth to form uniform orthogonal vip MOF(CoFe PBA)nanosheets.Phosphorus(P)is further introduced in situ to fabricate CoP and Fe_(2)P heterostructured nanosheets(CoFe-P-NS),which exhibit excellent bifunctional electrocatalytic performance due to the enhancement of intrinsic electrocatalytic activity by p-d orbital hybridization.Specifically,the CoFe-P-NS requires low overpotential of 259 and 307 mV to reach 500 mA cm−2 for HER and OER,respectively.Remarkably,the assembled electrolysis cell maintained a large current density of 300 mA cm−2 for over 360 h with negligible voltage increase during alkaline seawater electrolysis.Experiments and theoretical calculations show that the synergistic catalytic activity of bimetallic phosphides arises from p-d orbital hybridization,where the CoP-P sites enhance HER by optimizing H*adsorption in the Volmer-Heyrovsky steps,while the Fe_(2)P-Fe sites accelerate OER by lowering the energy barrier of the rate-determining step from O*to OOH*.This study provides valuable insights into the design of a controllable MOF-on-MOF-based electrocatalyst toward alkaline seawater splitting.展开更多
With the in-depth implementation of sustainable development strategies,hydrogen energy as a clean energy source is receiving increasing attention[1,2].Among the various methods of hydrogen production,the electrocataly...With the in-depth implementation of sustainable development strategies,hydrogen energy as a clean energy source is receiving increasing attention[1,2].Among the various methods of hydrogen production,the electrocatalytic decomposition of abundant seawater into hydrogen utilizing renewable energy has emerged as a green and promising approach.However,natural seawater contains complex components,such as halide ions,which lead to the corrosion of catalysts or the occurrence of competitive side reactions during the electrolysis process[3].展开更多
Titanium exhibits outstanding properties,particularly,high specific strength and resistance to both high and low temperatures,earning it a reputation as the metal of the future.However,because of the highly reactive n...Titanium exhibits outstanding properties,particularly,high specific strength and resistance to both high and low temperatures,earning it a reputation as the metal of the future.However,because of the highly reactive nature of titanium,metallic titanium production involves extensive procedures and high costs.Considering its advantages and limitations,the European Union has classified titanium metal as a critical raw material(CRM)of low category.The Kroll process is predominantly used to produce titanium;however,molten salt electrolysis(MSE)is currently being explored for producing metallic titanium at a low cost.Since 2000,electrolytic titanium production has undergone a wave of technological advancements.However,because of the intermediate and disproportionation reactions in the electrolytic titanium production process,the process efficiency and titanium purity according to industrial standards could not be achieved.Consequently,metallic titanium production has gradually diversified into employing technologies such as thermal reduction,MSE,and titanium alloy preparation.This study provides a comprehensive review of research advances in titanium metal preparation technologies over the past two decades,highlighting the challenges faced by the existing methods and proposing potential solutions.It offers useful insights into the development of low-cost titanium preparation technologies.展开更多
Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SO...Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SOECs with Zr-rich electrolyte,called Zr-rich side P-SOECs,possess high thermodynamically stability under high steam concentrations but the large reaction resistances and the current leakage,thus the inferior performances.In this study,an efficient functional interlayer Ba_(0.95)La_(0.05)Fe_(0.8)Zn_(0.2)O_(3-δ)(BLFZ)in-between the anode and the electrolyte is developed.The electrochemical performances of P-SOECs are greatly enhanced because the BLFZ can greatly increase the interface contact,boost anode reaction kinetics,and increase proton injection into electrolyte.As a result,the P-SOEC yields high current density of 0.83 A cm^(-2) at 600℃ in 1.3 Vamong all the reported Zr-rich side cells.This work not only offers an efficient functional interlayer for P-SOECs but also holds the potential to achieve P-SOECs with high performances and long-term stability.展开更多
Solid oxide electrolysis cells(SOECs)can effectively convert CO_(2)into high value-added CO fuel.In this paper,Sc-doped Sr_(2)Fe_(1.5)Mo_(0.3)Sc_(0.2)O_(6−δ)(SFMSc)perovskite oxide material is synthesized via solid-p...Solid oxide electrolysis cells(SOECs)can effectively convert CO_(2)into high value-added CO fuel.In this paper,Sc-doped Sr_(2)Fe_(1.5)Mo_(0.3)Sc_(0.2)O_(6−δ)(SFMSc)perovskite oxide material is synthesized via solid-phase method as the cathode for CO_(2)electrolysis by SOECs.XRD confirms that SFMSc exhibits a stable cubic phase crystal structure.The experimental results of TPD,TG,EPR,CO_(2)-TPD further demonstrate that Sc-doping increases the concentration of oxygen vacancy in the material and the chemical adsorption capacity of CO_(2)molecules.Electrochemical tests reveal that SFMSc single cell achieves a current density of 2.26 A/cm^(2) and a lower polarization impedance of 0.32Ω·cm^(2) at 800°C under the applied voltage of 1.8 V.And no significant performance attenuation or carbon deposition is observed after 80 h continuous long-term stability test.This study provides a favorable support for the development of SOEC cathode materials with good electro-catalytic performance and stability.展开更多
The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for...The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for hydrogen production.Despite remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable obstacle.This impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles detachment.To address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis system.Compared to constant voltage electrolysis(hydrogen production rate:51.6 m L h^(-1),energy consumption:5.37 kWh Nm-^(3)H_(2)),this strategy(hydrogen production rate:66 m L h^(-1),energy consumption:3.83 kWh Nm-^(3)H_(2))increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic(PV)system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 V.The combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis(PDE)dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode surface.As such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport processes.This promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.展开更多
Sodium(Na)and magnesium(Mg)are becoming important for making energy-storage batteries and structural materials.Herein,we develop a liquid-metal-electrode-assisted electrolysis route to producing Na and Mg with low-car...Sodium(Na)and magnesium(Mg)are becoming important for making energy-storage batteries and structural materials.Herein,we develop a liquid-metal-electrode-assisted electrolysis route to producing Na and Mg with low-carbon emissions and no chlorine gas evolution.The clean production stems from the choice of a molten NaCl-Na_(2)CO_(3) electrolyte to prevent chlorine gas evolution,an inert nickel-based anode to produce oxygen,and a liquid metal cathode to make the cathodic product sit at the bottom of the electrolytic cell.We achieve a current efficiency of>90%for the electrolytic production of liquid Na-Sn alloy.Later,Mg-Sn alloy is prepared using the obtained Na-Sn alloy to displace Mg from molten NaCl-MgCl_(2) with a displacement efficiency of>96%.Further,Na and Mg are separated from the electrolytic Na-Sn and displaced Mg-Sn alloys by vacuum distillation with a recovery rate of>92%and Sn can be reused.Using this electrolysisdisplacement-distillation(EDD)approach,we prepare Mg from seawater.The CO_(2)emission of the EDD approach is~20.6 kg CO_(2)per kg Mg,which is less than that of the Australian Magnesium(AM)electrolysis process(~25.0 kg CO_(2)per kg Mg)and less than half that of the Pidgeon process(~45.2 kg CO_(2)per kg Mg).展开更多
Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various ele...Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.展开更多
High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluor...High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluoride for roasting.Under the optimal leaching conditions of a fluorine to aluminum molar ratio of 2.0,a liquid-to-solid ratio of 12,a temperature of 90℃,and time of 4 h,the fluorine leaching rate can reach 99.15%.Under the action of electrolysis,the H+is reduced to H2 in the cathode,while the remaining OH−combines with AlF^(2+)and AlF^(2+)to precipitate aluminium hydroxyfluoride hydrate.The results show that electrolysis is beneficial to reduce the impurity content of aluminium hydroxyfluoride hydrate.When the current density is 0.2 A/cm^(2),the temperature is 90℃,the stirring speed is 200 r/min,and the electrolysis endpoint pH is 3.0,the total content of Na,K and Ca impurities in the precipitation is only 0.64 wt.%.Moreover,the hydrolysis can be inhibited effectively by adding ammonium hydrogen fluoride in the mixed-roasting process.When the mass ratio of aluminium hydroxyfluoride hydrate to ammonium hydrogen fluoride is 2꞉1,the purity of the AlF3 product is even 99.51 wt.%.Conducively,the high-purity AlF_(3)can be returned to the aluminum electrolysis industry or used as a reagent.展开更多
Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct c...Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.展开更多
Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojuncti...Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojunction catalyst confined in carbon nanofiber with spontaneous charge redistribution driven by high valent metal,which promotes the adsorption and transformation of intermediates and greatly reduces the reaction energy barrier for urea oxidation.The heterojunction catalyst promotes the formation of Ni^(3+)active species and accelerates the fracture of the C-N bond by enhancing selective adsorption of-NH_(2)and C=O groups in binding urea molecules driven by the spontaneous formation of nucleophilic and electrophilic sites.The catalyst achieves a low kinetic current density of 10 mA cm^(-2)at 1.35 V with a cell voltage for urea electrolysis of just 1.47 V and good durability over 60 h.Density-functional theory and in-situ spectral observation reveal that the high valent Mo promoted the 3d orbit of Ni approaching the Fermi level by adjusting the electronic structure,which enhanced spontaneous urea dehydrogenation and reduced the energy barrier for^(*)COO desorption.This study highlights the effectiveness of modulating the interfacial electronic structure to improve energy conversion efficiency.展开更多
This work investigates the transient performance and stability of CO_(2)/H_(2)O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell(SOEC)stack.The results showed that the transie...This work investigates the transient performance and stability of CO_(2)/H_(2)O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell(SOEC)stack.The results showed that the transient behavior of the stack with and without blowing gas into the air electrode is almost the same.With a current density of 0.67 A·cm^(-2)@750℃,the stack operated for over 200 h under co-electrolysis conditions without air blowing,and the voltage drop rate of the stack was approximately 0.203%/100 hours.Microstructure analysis revealed a significant loss of nickel particles and an apparent for-mation of an insulating phase strontium chromate(SrCrO4)on the surface of the current collection layer of the air electrode,which are identified as key factors contributing to the performance degradation of the stack.This study provides a reference for development of efficient fuel preparation technology based on SOEC stack in airless environments.展开更多
Electrocatalytic carbon dioxide reduction is a promising technology for addressing global energy and environmental crises. However, its practical application faces two critical challenges: the complex and energy-inten...Electrocatalytic carbon dioxide reduction is a promising technology for addressing global energy and environmental crises. However, its practical application faces two critical challenges: the complex and energy-intensive process of separat-ing mixed reduction products and the economic viability of the carbon sources (reactants) used. To tackle these challenges simultaneously, solid-state electrolyte (SSE) reactors are emerging as a promising solution. In this review, we focus on the feasibility of applying SSE for tandem electrochemical CO_(2) capture and conversion. The configurations and fundamental principles of SSE reactors are first discussed, followed by an introduction to its applications in these two specific areas, along with case studies on the implementation of tandem electrolysis. In comparison to conventional H-type cell, flow cell and membrane electrode assembly cell reactors, SSE reactors incorporate gas diffusion electrodes and utilize a solid electro-lyte layer positioned between an anion exchange membrane (AEM) and a cation exchange membrane (CEM). A key inno-vation of this design is the sandwiched SSE layer, which enhances efficient ion transport and facilitates continuous product extraction through a stream of deionized water or humidified nitrogen, effectively separating ion conduction from product collection. During electrolysis, driven by an electric field and concentration gradient, electrochemically generated ions (e.g., HCOO- and CH3COO-) migrate through the AEM into the SSE layer, while protons produced from water oxidation at the anode traverse the CEM into the central chamber to maintain charge balance. Targeted products like HCOOH can form in the middle layer through ionic recombination and are efficiently carried away by the flowing medium through the porous SSE layer, in the absence of electrolyte salt impurities. As CO_(2)RR can generate a series of liquid products, advancements in catalyst discovery over the past several years have facilitated the industrial application of SSE for more efficient chemicals production. Also noteworthy, the cathode reduction reaction can readily consume protons from water, creating a highly al-kaline local environment. SSE reactors are thereby employed to capture acidic CO_(2), forming CO_(3)^(2-) from various gas sources including flue gases. Driven by the electric field, the formed CO_(3)^(2-) can traverse through the AEM and react with protons originating from the anode, thereby regenerating CO_(2). This CO_(2) can then be collected and utilized as a low-cost feedstock for downstream CO_(2) electrolysis. Based on this principle, several cell configurations have been proposed to enhance CO_(2) capture from diverse gas sources. Through the collaboration of two SSE units, tandem electrochemical CO_(2) capture and con-version has been successfully implemented. Finally, we offer insights into the future development of SSE reactors for prac-tical applications aimed at achieving carbon neutrality. We recommend that greater attention be focused on specific aspects, including the fundamental physicochemical properties of the SSE layer, the electrochemical engineering perspective related to ion and species fluxes and selectivity, and the systematic pairing of consecutive CO_(2) capture and conversion units. These efforts aim to further enhance the practical application of SSE reactors within the broader electrochemistry community.展开更多
CO_(2)electrolysis using solid oxide electrolysis cells is a promising technology for CO_(2)utilization and conversion,which has attracted more and more attention in recent years because of its extremely high efficien...CO_(2)electrolysis using solid oxide electrolysis cells is a promising technology for CO_(2)utilization and conversion,which has attracted more and more attention in recent years because of its extremely high efficiency.However,traditional Ni-yttria-stabilized zirconia(Ni-YSZ)or Ni-Gd_(0.1)Ce_(0.9)O_(2-δ)(Ni-GDC)metal-ceramic cathode faces many problems such as Ni agglomeration and carbon deposition during long-time operation.Herein,a perovskite oxide La_(0.43-x)Ca_(0.37)Ti_(0.9)Ni_(0.1)O_(3-δ)(LCTN,x=0,0.05,0.1)with nanophase-LaVO_(4)exsolution was investigated as the novel cathode of solid oxide electrolysis cell(SOEC)for efficient CO_(2)electrolysis.The results confirm that the exsolution nanophase on LCTN surface can significantly improve the CO_(2)adsorption and conversion performance.For CO_(2)electrolysis at 1.8 V,an electrolysis current density of 1.24 A/cm2at 800℃can be obtained on SOEC with La_(0.43-x)Ca_(0.37)Ti_(0.9)Ni_(0.1)O_(3-δ)decorated with LaVO_(4)(LCTN-V0.05)cathode.Furthermore,the corresponding cell can maintain stable operation up to 100 h without apparent performance degradation.These results demonstrate that doping-induced second nanophase exsolution is a promising way to design high-performance SOEC cathodes for CO_(2)electrolysis.展开更多
The rising level of CO_(2) concentration in the atmosphere poses major threats to the global climate and environment.Various technologies have been developed to mitigate its negative effects through nonconversion and ...The rising level of CO_(2) concentration in the atmosphere poses major threats to the global climate and environment.Various technologies have been developed to mitigate its negative effects through nonconversion and conversion routes.Particularly,solid oxide electrolysis cells(SOECs),as a promising technology with the highest energy efficiency,have garnered considerable attention for their effectiveness to electrochemically convert CO_(2) into high-value fuels.However,the insufficient catalytic activity,poor longterm stability,and high costs have significantly hindered the industrial-scale application of SOECs.To this end,substantial efforts,with an emphasis on the smart design of targeting electrode materials for specific applications have been devoted to advancing the electrosynthesis of high-value fuels from CO_(2) in various SOECs,but there still lacks a critical and comprehensive review in-depth discussing the fundamentals,and summarizing the latest advances in various applications and electrode materials for electrochemically converting CO_(2) to high-value fuels in SOECs.This review thus aims to fill this gap by focusing on the fundamentals(i.e.,SOEC working principles,thermodynamics,kinetics and representative evaluation parameters),specific applications(i.e.,pure CO_(2) electrolysis,CO_(2)-H_(2)O co-electrolysis,fuel-assisted CO_(2) conversion),and material selection criteria(i.e.,cathodic materials for CO_(2) conversion,and anodic materials for fuel-assisted CO_(2) conversion).In addition,the challenges that this technology is currently facing,and our perspectives on electrochemical CO_(2) conversion in SOECs are proposed to guide the smart design of high-performance electrocatalysts and future industrial-scale application of SOECs for electrosynthesizing high-value fuels from CO_(2).展开更多
Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that sy...Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that synergizes CO_(2)-H_(2)O co-electrolysis(producing CO/O_(2) feeds)with oxidative double carbonylation of ethylene/acetylene to synthesize CO_(2)-derived C_(4) diesters(dimethyl succinate,fumarate,and maleate).A group of versatile building blocks for manufacturing plasticizers,biodegradable polymers,and pharmaceutical intermediates.Remarkably,CO_(2) exhibits dual functionality:serving simultaneously as a CO/O_(2) source and an explosion suppressant during the oxidative carbonylation process.We systematically investigated the explosion-suppressing efficacy of CO_(2) in flammable gas mixtures(CO/O_(2),C_(2)H_(4)/CO/O_(2),and C_(2)H_(2)/CO/O_(2))across varying concentrations.Notably,the mixed gas stream from CO_(2)/H_(2)O co-electrolysis at an industrial-scale current densities of 400 mA/cm^(2),enabling direct utilization in oxidative double carbonylation reactions with exceptional compatibility and inherent safety.Extended applications were demonstrated through substrate scope expansion and gram-scale synthesis.This study establishes not only a safe protocol for oxidative carbonylation processes,but also opens an innovative pathway for sustainable CO_(2) valorization,including CO surrogate and explosion suppressant.展开更多
文摘The neodymium electrolysis produces unnecessary high emission of CF4 and C2F6. These perfluorocarbons (PFCs) are potent greenhouse gases and are not filtered or destroyed in the off-gas. A process control in analogy to the aluminum electrolysis can reduce the PFC emission to a great extend and keep the process in a green process window. Therefore, a theoretical analysis is done of the cell voltage of the industrial neodymium electrolysis in dependence on the neodymium oxide concentration in the electrolyte. The analysis shows the different contributions to the cell voltage focusing on the impact of the anodic overvoltage on the cell voltage, by which the electrolysis process can be controlled. The model of the cell voltage is evaluated by laboratory neodymium electrolysis with a similar setup as the industrial cell. The relation of the oxide concentration, the anodic current density and the cell voltage with the cell resistance are measured. The continuous off-gas measurements show the gas concentration and PFC emissions. The effect of Nd2O3 feeding on the galvanostatic electrolysis is analyzed as well. Based on the results a process control strategy is proposed similar to the aluminum electrolysis strategy. The green process window is in a narrow oxide concentration range, making a continuous and precise oxide feeding essential.
基金supported by the National Key Research and Development Program of China (2022YFE0138900)the “Scientific and Technical Innovation Action Plan” Basic Research Field of Shanghai Science and Technology Committee (19JC1410500)。
文摘Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.
基金financially supported by the Key Research and Development Program of Heilongjiang Province(No.2024ZXJ03C06)National Natural Science Foundation of China(No.52476192,No.52106237)+1 种基金Natural Science Foundation of Heilongjiang Province(No.YQ2022E027)Technology Project of China Datang Technology Innovation Co.,Ltd(No.DTKC-2024-20610).
文摘Pulsed dynamic electrolysis(PDE),driven by renewable energy,has emerged as an innovative electrocatalytic conversion method,demonstrating significant potential in addressing global energy challenges and promoting sustainable development.Despite significant progress in various electrochemical systems,the regulatory mechanisms of PDE in energy and mass transfer and the lifespan extension of electrolysis systems,particularly in water electrolysis(WE)for hydrogen production,remain insufficiently explored.Therefore,there is an urgent need for a deeper understanding of the unique contributions of PDE in mass transfer enhancement,microenvironment regulation,and hydrogen production optimization,aiming to achieve low-energy consumption,high catalytic activity,and long-term stability in the generation of target products.Here,this review critically examines the microenvironmental effects of PDE on energy and mass transfer,the electrode degradation mechanisms in the lifespan extension of electrolysis systems,and the key factors in enhancing WE for hydrogen production,providing a comprehensive summary of current research progress.The review focuses on the complex regulatory mechanisms of frequency,duty cycle,amplitude,and other factors in hydrogen evolution reaction(HER)performance within PDE strategies,revealing the interrelationships among them.Finally,the potential future directions and challenges for transitioning from laboratory studies to industrial applications are proposed.
基金Supported by the Project of Design of Anti-corrosion and Anti-fouling Solutions for Offshore Wind Power Water-Cooled Systems(No.E428161)the National Natural Science Foundation of China(No.42176047)。
文摘Water-cooled system have significantly enhanced the power generation efficiency of offshore wind turbines.However,these innovative systems are susceptible to substantial biological fouling,maintenance challenges,and high upkeep costs.Therefore,the development of a specialized front-end filter tailored for direct current water-cooled system is importance.This involves the integration of dimensionally stable anode(DSA)and nickel alloy cathode,valued for their corrosion resistance in seawater,into a novel front-end filter system for Water-cooled applications.This system has the dual capability of generating hydrogen and chlorine for self-cleaning purposes.Implementing a flushing pulse electrolysis mode,it effectively mitigates electrode failure induced by cathodic calcium and magnesium deposition,thereby significantly prolonging electrode lifespan.Laboratory tests comprising system assembly and performance evaluations were conducted,with the system programmed to operate for 5 minutes every 24 hours under continuous flushing by natural seawater to simulate real-world conditions.After more than 11 months of continuous flushing,observations reveal that the DSA mesh and nickel alloy mesh maintain intact structural integrity and normal functioning.Subsequent 1꞉1 physical prototype Sea trial further validated the soundness of the system design and electrolytic control parameters.
基金financial support of the National Natural Science Foundation of China (21875247,21072221, 21172252)the Project of Talent Cultivation for Carbon Peak and Carbon Neutrality of the University of Chinese of Academy of Science
文摘The design and fabrication of ordered epitaxial MOF-on-MOF heterostructures as highly efficient electrocatalysts for water splitting is crucial but still challenging.In this study,a simple coordination-driven self-assembly method is used to fabricate controllable MOF-on-MOF multiscale heterostructures,where triangular host MOF(ZIF-67)nanosheets undergo in situ epitaxial growth to form uniform orthogonal vip MOF(CoFe PBA)nanosheets.Phosphorus(P)is further introduced in situ to fabricate CoP and Fe_(2)P heterostructured nanosheets(CoFe-P-NS),which exhibit excellent bifunctional electrocatalytic performance due to the enhancement of intrinsic electrocatalytic activity by p-d orbital hybridization.Specifically,the CoFe-P-NS requires low overpotential of 259 and 307 mV to reach 500 mA cm−2 for HER and OER,respectively.Remarkably,the assembled electrolysis cell maintained a large current density of 300 mA cm−2 for over 360 h with negligible voltage increase during alkaline seawater electrolysis.Experiments and theoretical calculations show that the synergistic catalytic activity of bimetallic phosphides arises from p-d orbital hybridization,where the CoP-P sites enhance HER by optimizing H*adsorption in the Volmer-Heyrovsky steps,while the Fe_(2)P-Fe sites accelerate OER by lowering the energy barrier of the rate-determining step from O*to OOH*.This study provides valuable insights into the design of a controllable MOF-on-MOF-based electrocatalyst toward alkaline seawater splitting.
基金financially supported by the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(No.NY223016)Qinglan Project of Jiangsu Province of China2024 Nanjing Science and Technology Innovation Program(No.NJKCZYZZ2024-06)。
文摘With the in-depth implementation of sustainable development strategies,hydrogen energy as a clean energy source is receiving increasing attention[1,2].Among the various methods of hydrogen production,the electrocatalytic decomposition of abundant seawater into hydrogen utilizing renewable energy has emerged as a green and promising approach.However,natural seawater contains complex components,such as halide ions,which lead to the corrosion of catalysts or the occurrence of competitive side reactions during the electrolysis process[3].
基金financial support from the Yunnan Province Key Industries Science and Technology Special Project for Colleges and UniversitiesChina(No.FWCY-QYCT2024006)+6 种基金National Natural Science Foundation of China(Nos.52104351 and 52364051)Science and Technology Major Project of Yunnan Province,China(No.202202AG050007)the Yunnan Fundamental Research ProjectsChina(No.202401AT070314)the Key Technology Research and Development Program of Shandong Province,China(No.2023CXGC010903)Central Guidance Local Scientific and Technological Development Funds,China(No.202407AB110022)Yunnan Province Xingdian Talent Support Plan Project,China。
文摘Titanium exhibits outstanding properties,particularly,high specific strength and resistance to both high and low temperatures,earning it a reputation as the metal of the future.However,because of the highly reactive nature of titanium,metallic titanium production involves extensive procedures and high costs.Considering its advantages and limitations,the European Union has classified titanium metal as a critical raw material(CRM)of low category.The Kroll process is predominantly used to produce titanium;however,molten salt electrolysis(MSE)is currently being explored for producing metallic titanium at a low cost.Since 2000,electrolytic titanium production has undergone a wave of technological advancements.However,because of the intermediate and disproportionation reactions in the electrolytic titanium production process,the process efficiency and titanium purity according to industrial standards could not be achieved.Consequently,metallic titanium production has gradually diversified into employing technologies such as thermal reduction,MSE,and titanium alloy preparation.This study provides a comprehensive review of research advances in titanium metal preparation technologies over the past two decades,highlighting the challenges faced by the existing methods and proposing potential solutions.It offers useful insights into the development of low-cost titanium preparation technologies.
基金financial support from the JSPS KAKENHI Grant-in-Aid for Scientific Research(B),No.21H02035KAKENHI Grant-in-Aid for Challenging Research(Exploratory),No.21K19017+2 种基金KAKENHI Grant-in-Aid for Transformative Research Areas(B),No.21H05100National Natural Science Foundation of China,No.22409033 and No.22409035Basic and Applied Basic Research Foundation of Guangdong Province,No.2022A1515110470.
文摘Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SOECs with Zr-rich electrolyte,called Zr-rich side P-SOECs,possess high thermodynamically stability under high steam concentrations but the large reaction resistances and the current leakage,thus the inferior performances.In this study,an efficient functional interlayer Ba_(0.95)La_(0.05)Fe_(0.8)Zn_(0.2)O_(3-δ)(BLFZ)in-between the anode and the electrolyte is developed.The electrochemical performances of P-SOECs are greatly enhanced because the BLFZ can greatly increase the interface contact,boost anode reaction kinetics,and increase proton injection into electrolyte.As a result,the P-SOEC yields high current density of 0.83 A cm^(-2) at 600℃ in 1.3 Vamong all the reported Zr-rich side cells.This work not only offers an efficient functional interlayer for P-SOECs but also holds the potential to achieve P-SOECs with high performances and long-term stability.
基金supported by National Key R&D Program of China(2021YFB4001401)National Natural Science Foundation of China(52272190,22178023).
文摘Solid oxide electrolysis cells(SOECs)can effectively convert CO_(2)into high value-added CO fuel.In this paper,Sc-doped Sr_(2)Fe_(1.5)Mo_(0.3)Sc_(0.2)O_(6−δ)(SFMSc)perovskite oxide material is synthesized via solid-phase method as the cathode for CO_(2)electrolysis by SOECs.XRD confirms that SFMSc exhibits a stable cubic phase crystal structure.The experimental results of TPD,TG,EPR,CO_(2)-TPD further demonstrate that Sc-doping increases the concentration of oxygen vacancy in the material and the chemical adsorption capacity of CO_(2)molecules.Electrochemical tests reveal that SFMSc single cell achieves a current density of 2.26 A/cm^(2) and a lower polarization impedance of 0.32Ω·cm^(2) at 800°C under the applied voltage of 1.8 V.And no significant performance attenuation or carbon deposition is observed after 80 h continuous long-term stability test.This study provides a favorable support for the development of SOEC cathode materials with good electro-catalytic performance and stability.
基金National Natural Science Foundation of China(No.52476192,No.52106237)Natural Science Foundation of Heilongjiang Province(No.YQ2022E027)。
文摘The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for hydrogen production.Despite remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable obstacle.This impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles detachment.To address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis system.Compared to constant voltage electrolysis(hydrogen production rate:51.6 m L h^(-1),energy consumption:5.37 kWh Nm-^(3)H_(2)),this strategy(hydrogen production rate:66 m L h^(-1),energy consumption:3.83 kWh Nm-^(3)H_(2))increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic(PV)system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 V.The combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis(PDE)dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode surface.As such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport processes.This promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.
基金support from the National Natural Science Foundation of China(No’s.U22B2071,51874211,52031008)the Chilwee Group(CWDY-ZH-YJY-202101-001).
文摘Sodium(Na)and magnesium(Mg)are becoming important for making energy-storage batteries and structural materials.Herein,we develop a liquid-metal-electrode-assisted electrolysis route to producing Na and Mg with low-carbon emissions and no chlorine gas evolution.The clean production stems from the choice of a molten NaCl-Na_(2)CO_(3) electrolyte to prevent chlorine gas evolution,an inert nickel-based anode to produce oxygen,and a liquid metal cathode to make the cathodic product sit at the bottom of the electrolytic cell.We achieve a current efficiency of>90%for the electrolytic production of liquid Na-Sn alloy.Later,Mg-Sn alloy is prepared using the obtained Na-Sn alloy to displace Mg from molten NaCl-MgCl_(2) with a displacement efficiency of>96%.Further,Na and Mg are separated from the electrolytic Na-Sn and displaced Mg-Sn alloys by vacuum distillation with a recovery rate of>92%and Sn can be reused.Using this electrolysisdisplacement-distillation(EDD)approach,we prepare Mg from seawater.The CO_(2)emission of the EDD approach is~20.6 kg CO_(2)per kg Mg,which is less than that of the Australian Magnesium(AM)electrolysis process(~25.0 kg CO_(2)per kg Mg)and less than half that of the Pidgeon process(~45.2 kg CO_(2)per kg Mg).
基金support from the National Natural Science Foundation of China(Grant No.52006029)the Promotion Foundation for Young Science and Technology Talents in Jilin Province(Grant No.QT202113)+2 种基金the Special Foundation of Industrial Innovation in Jilin Province(Grant No.2019C056-2)the Special Foundation for Outstanding Young Talents Training in Jilin(Grant No.20200104107)the UK EPSRC(EP/W03784X/1)。
文摘Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.
文摘High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluoride for roasting.Under the optimal leaching conditions of a fluorine to aluminum molar ratio of 2.0,a liquid-to-solid ratio of 12,a temperature of 90℃,and time of 4 h,the fluorine leaching rate can reach 99.15%.Under the action of electrolysis,the H+is reduced to H2 in the cathode,while the remaining OH−combines with AlF^(2+)and AlF^(2+)to precipitate aluminium hydroxyfluoride hydrate.The results show that electrolysis is beneficial to reduce the impurity content of aluminium hydroxyfluoride hydrate.When the current density is 0.2 A/cm^(2),the temperature is 90℃,the stirring speed is 200 r/min,and the electrolysis endpoint pH is 3.0,the total content of Na,K and Ca impurities in the precipitation is only 0.64 wt.%.Moreover,the hydrolysis can be inhibited effectively by adding ammonium hydrogen fluoride in the mixed-roasting process.When the mass ratio of aluminium hydroxyfluoride hydrate to ammonium hydrogen fluoride is 2꞉1,the purity of the AlF3 product is even 99.51 wt.%.Conducively,the high-purity AlF_(3)can be returned to the aluminum electrolysis industry or used as a reagent.
文摘Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.
基金supported by the National Natural Science Foundation of China(22272148,22202172)financial support from the China Postdoctoral Science Foundation(2023M742947)support of the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Yangzhou University)(KYCX24_3720)。
文摘Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojunction catalyst confined in carbon nanofiber with spontaneous charge redistribution driven by high valent metal,which promotes the adsorption and transformation of intermediates and greatly reduces the reaction energy barrier for urea oxidation.The heterojunction catalyst promotes the formation of Ni^(3+)active species and accelerates the fracture of the C-N bond by enhancing selective adsorption of-NH_(2)and C=O groups in binding urea molecules driven by the spontaneous formation of nucleophilic and electrophilic sites.The catalyst achieves a low kinetic current density of 10 mA cm^(-2)at 1.35 V with a cell voltage for urea electrolysis of just 1.47 V and good durability over 60 h.Density-functional theory and in-situ spectral observation reveal that the high valent Mo promoted the 3d orbit of Ni approaching the Fermi level by adjusting the electronic structure,which enhanced spontaneous urea dehydrogenation and reduced the energy barrier for^(*)COO desorption.This study highlights the effectiveness of modulating the interfacial electronic structure to improve energy conversion efficiency.
基金co-supported by the National Key R&D Program of China(No.2022YFB4002203)Baima Lake Laboratory Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(No.LBMHY24B060003)Ningbo Key R&D Project(No.2023Z155).
文摘This work investigates the transient performance and stability of CO_(2)/H_(2)O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell(SOEC)stack.The results showed that the transient behavior of the stack with and without blowing gas into the air electrode is almost the same.With a current density of 0.67 A·cm^(-2)@750℃,the stack operated for over 200 h under co-electrolysis conditions without air blowing,and the voltage drop rate of the stack was approximately 0.203%/100 hours.Microstructure analysis revealed a significant loss of nickel particles and an apparent for-mation of an insulating phase strontium chromate(SrCrO4)on the surface of the current collection layer of the air electrode,which are identified as key factors contributing to the performance degradation of the stack.This study provides a reference for development of efficient fuel preparation technology based on SOEC stack in airless environments.
基金This work was supported by the National Key R&D Program of China(2022YFB4102000 and 2022YFA1505100)the NSFC(22472038)the Shanghai Science and Technology Innovation Action Plan(22dz1205500).
文摘Electrocatalytic carbon dioxide reduction is a promising technology for addressing global energy and environmental crises. However, its practical application faces two critical challenges: the complex and energy-intensive process of separat-ing mixed reduction products and the economic viability of the carbon sources (reactants) used. To tackle these challenges simultaneously, solid-state electrolyte (SSE) reactors are emerging as a promising solution. In this review, we focus on the feasibility of applying SSE for tandem electrochemical CO_(2) capture and conversion. The configurations and fundamental principles of SSE reactors are first discussed, followed by an introduction to its applications in these two specific areas, along with case studies on the implementation of tandem electrolysis. In comparison to conventional H-type cell, flow cell and membrane electrode assembly cell reactors, SSE reactors incorporate gas diffusion electrodes and utilize a solid electro-lyte layer positioned between an anion exchange membrane (AEM) and a cation exchange membrane (CEM). A key inno-vation of this design is the sandwiched SSE layer, which enhances efficient ion transport and facilitates continuous product extraction through a stream of deionized water or humidified nitrogen, effectively separating ion conduction from product collection. During electrolysis, driven by an electric field and concentration gradient, electrochemically generated ions (e.g., HCOO- and CH3COO-) migrate through the AEM into the SSE layer, while protons produced from water oxidation at the anode traverse the CEM into the central chamber to maintain charge balance. Targeted products like HCOOH can form in the middle layer through ionic recombination and are efficiently carried away by the flowing medium through the porous SSE layer, in the absence of electrolyte salt impurities. As CO_(2)RR can generate a series of liquid products, advancements in catalyst discovery over the past several years have facilitated the industrial application of SSE for more efficient chemicals production. Also noteworthy, the cathode reduction reaction can readily consume protons from water, creating a highly al-kaline local environment. SSE reactors are thereby employed to capture acidic CO_(2), forming CO_(3)^(2-) from various gas sources including flue gases. Driven by the electric field, the formed CO_(3)^(2-) can traverse through the AEM and react with protons originating from the anode, thereby regenerating CO_(2). This CO_(2) can then be collected and utilized as a low-cost feedstock for downstream CO_(2) electrolysis. Based on this principle, several cell configurations have been proposed to enhance CO_(2) capture from diverse gas sources. Through the collaboration of two SSE units, tandem electrochemical CO_(2) capture and con-version has been successfully implemented. Finally, we offer insights into the future development of SSE reactors for prac-tical applications aimed at achieving carbon neutrality. We recommend that greater attention be focused on specific aspects, including the fundamental physicochemical properties of the SSE layer, the electrochemical engineering perspective related to ion and species fluxes and selectivity, and the systematic pairing of consecutive CO_(2) capture and conversion units. These efforts aim to further enhance the practical application of SSE reactors within the broader electrochemistry community.
基金Project supported by the National Key Research&Development Project(2023YFB4006001)National Natural Science Foundation of China(52172199)。
文摘CO_(2)electrolysis using solid oxide electrolysis cells is a promising technology for CO_(2)utilization and conversion,which has attracted more and more attention in recent years because of its extremely high efficiency.However,traditional Ni-yttria-stabilized zirconia(Ni-YSZ)or Ni-Gd_(0.1)Ce_(0.9)O_(2-δ)(Ni-GDC)metal-ceramic cathode faces many problems such as Ni agglomeration and carbon deposition during long-time operation.Herein,a perovskite oxide La_(0.43-x)Ca_(0.37)Ti_(0.9)Ni_(0.1)O_(3-δ)(LCTN,x=0,0.05,0.1)with nanophase-LaVO_(4)exsolution was investigated as the novel cathode of solid oxide electrolysis cell(SOEC)for efficient CO_(2)electrolysis.The results confirm that the exsolution nanophase on LCTN surface can significantly improve the CO_(2)adsorption and conversion performance.For CO_(2)electrolysis at 1.8 V,an electrolysis current density of 1.24 A/cm2at 800℃can be obtained on SOEC with La_(0.43-x)Ca_(0.37)Ti_(0.9)Ni_(0.1)O_(3-δ)decorated with LaVO_(4)(LCTN-V0.05)cathode.Furthermore,the corresponding cell can maintain stable operation up to 100 h without apparent performance degradation.These results demonstrate that doping-induced second nanophase exsolution is a promising way to design high-performance SOEC cathodes for CO_(2)electrolysis.
基金supported by the Pilot Group Program of the Research Fund for International Senior Scientists(No.22350710789)the National Natural Science Foundation of China(NSFC,No.22109182)+2 种基金the Natural Science Foundation of Hunan Province,China(No.2022JJ30684)the Start-up Funding of Central South University(No.206030104)supported in part by the High-Performance Computing Center of Central South University。
文摘The rising level of CO_(2) concentration in the atmosphere poses major threats to the global climate and environment.Various technologies have been developed to mitigate its negative effects through nonconversion and conversion routes.Particularly,solid oxide electrolysis cells(SOECs),as a promising technology with the highest energy efficiency,have garnered considerable attention for their effectiveness to electrochemically convert CO_(2) into high-value fuels.However,the insufficient catalytic activity,poor longterm stability,and high costs have significantly hindered the industrial-scale application of SOECs.To this end,substantial efforts,with an emphasis on the smart design of targeting electrode materials for specific applications have been devoted to advancing the electrosynthesis of high-value fuels from CO_(2) in various SOECs,but there still lacks a critical and comprehensive review in-depth discussing the fundamentals,and summarizing the latest advances in various applications and electrode materials for electrochemically converting CO_(2) to high-value fuels in SOECs.This review thus aims to fill this gap by focusing on the fundamentals(i.e.,SOEC working principles,thermodynamics,kinetics and representative evaluation parameters),specific applications(i.e.,pure CO_(2) electrolysis,CO_(2)-H_(2)O co-electrolysis,fuel-assisted CO_(2) conversion),and material selection criteria(i.e.,cathodic materials for CO_(2) conversion,and anodic materials for fuel-assisted CO_(2) conversion).In addition,the challenges that this technology is currently facing,and our perspectives on electrochemical CO_(2) conversion in SOECs are proposed to guide the smart design of high-performance electrocatalysts and future industrial-scale application of SOECs for electrosynthesizing high-value fuels from CO_(2).
文摘Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that synergizes CO_(2)-H_(2)O co-electrolysis(producing CO/O_(2) feeds)with oxidative double carbonylation of ethylene/acetylene to synthesize CO_(2)-derived C_(4) diesters(dimethyl succinate,fumarate,and maleate).A group of versatile building blocks for manufacturing plasticizers,biodegradable polymers,and pharmaceutical intermediates.Remarkably,CO_(2) exhibits dual functionality:serving simultaneously as a CO/O_(2) source and an explosion suppressant during the oxidative carbonylation process.We systematically investigated the explosion-suppressing efficacy of CO_(2) in flammable gas mixtures(CO/O_(2),C_(2)H_(4)/CO/O_(2),and C_(2)H_(2)/CO/O_(2))across varying concentrations.Notably,the mixed gas stream from CO_(2)/H_(2)O co-electrolysis at an industrial-scale current densities of 400 mA/cm^(2),enabling direct utilization in oxidative double carbonylation reactions with exceptional compatibility and inherent safety.Extended applications were demonstrated through substrate scope expansion and gram-scale synthesis.This study establishes not only a safe protocol for oxidative carbonylation processes,but also opens an innovative pathway for sustainable CO_(2) valorization,including CO surrogate and explosion suppressant.
