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
Enhancing the electrosynthesis of hydrogen peroxide(H_(2)O_(2))(the two-electron oxygen reduction and 2e−ORR)is critical for decentralized and on-site H_(2)O_(2) production.However,the high aeration energy consumption...Enhancing the electrosynthesis of hydrogen peroxide(H_(2)O_(2))(the two-electron oxygen reduction and 2e−ORR)is critical for decentralized and on-site H_(2)O_(2) production.However,the high aeration energy consumption and serious side reactions in the 2e−ORR system have decreased its 2e−ORR performance,hindering its further application.Herein,we greatly reduced the aeration energy consumption using anode-produced O_(2) for the cathode 2e−ORR(anode-cathode coupling)and further decreased the hydrogen evolution reaction(HER)and H_(2)O_(2) electroreduction by applying pulses.A flowthrough reactor with narrow electrode gaps efficiently improves the utilization of anode-produced O_(2).It increased the effluent H_(2)O_(2) concentration by 101.22%compared to non-coupled systems.In addition,pulsed electrolysis increased the effluent H_(2)O_(2) concentration and current efficiency by 3.41 and 11.38 times,respectively.During the power-off period,the electrochemical reaction paused,whereas the O_(2) and H_(2)O_(2) diffusion continued under the concentration gradient.These processes relieve the O_(2) shortage at the cathodes to decrease the HER and alleviate H_(2)O_(2) accumulation at the cathodes,thus reducing its decomposition.Our results provide an easy and efficient way to improve H_(2)O_(2) electrosynthesis performance.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
Electrochemical transformation emerges as an important solution to sustainable energy conversion and chemical production.Conventional electrolytic systems usually operate under galvanostatic or potentiostatic conditio...Electrochemical transformation emerges as an important solution to sustainable energy conversion and chemical production.Conventional electrolytic systems usually operate under galvanostatic or potentiostatic conditions that sometimes result in unsatisfactory efficiencies or selectivities.Pulse electrolysis by pulsating and programming the potentials/currents can feature unique tunability to the electrodeelectrolyte interface properties that can give rise to drastically different electrochemical behaviors compared to the steady-state counterparts.Although invented almost 100 years ago,pulse electrolysis has received little attention over the period,but has recently attracted a revived focus toward the energyefficient electrolysis.This review will summarize the history and recent efforts of pulse electrolysis in three categories:water electrolysis,CO_(2)electrolysis and other electrolysis.In each section,the advantage of pulse electrolysis over steady-state electrolysis will be discussed in detail,giving a comprehensive overview of the pulse effect on the electrolytic systems.Finally,we will provide our vision of future directions in pulse electrolysis based on previous works.展开更多
Pulsed electrolysis for CO_(2)reduction reaction has emerged as an effective method to enhance catalyst efficiency and optimize product selectivity.However,challenges remain in understanding the mechanisms of surface ...Pulsed electrolysis for CO_(2)reduction reaction has emerged as an effective method to enhance catalyst efficiency and optimize product selectivity.However,challenges remain in understanding the mechanisms of surface transformation under pulsed conditions.In this study,using in-situ time-resolved surface-enhanced Raman spectroscopy and differential electrochemical mass spectroscopy,we found local pH at the surface and Cu–O–C species that was generated during the anodic pulse played a key role in pulsed electrolysis.During the pulsed oxidation,an oxidation layer first formed,depleting OH–and lowering the local pH.When the pH was below 8.4,HCO_(3)–transformed the oxidation layer to a nanometer-thick Cu–O–C species,which is a highly reactive catalyst.In the reduction pulse,about 7.4%of the surface Cu–O–C was transformed into CO and CuOx species,enhancing CO_(2)reduction activity.Even in Ar-saturated 0.1 M KHCO_(3),through a Cu–O–C intermediate,a Faradaic efficiency of 0.17%for bicarbonate reduction to CO was observed.Our findings highlight the crucial role of the anodic pulse process in improving CO_(2)reduction activity.展开更多
Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for ...Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for productions of materials with well-defined functional properties.Pulse electrolysis,a top-down electrochemical approach,has been demonstrated to be a viable method for producing nanostructured materials with a particular efficacy in the synthesis of tin oxides.This method allows for significant control over the composition and shape of the resulting tin oxides particles by modifying the anionic composition of the aqueous electrolyte,obviating the need for additional capping agents in the synthesis process and eliminating the requirement for high-temperature post-treatments.The composition and microstructural characteristics of these oxides are found to be contingent upon the differing stabilities of tin fluoride and chloride complexes,as well as the distinct mechanisms of interaction between chloride and fluoride anions with an oxidized tin surface,which is influenced by the varying kosmotropic/chaotropic nature of these anions.The composition and microstructural characteristics of the obtained dispersed tin oxides would thus determine their potential applications as an anode material for lithium-ion batteries,as a photocatalyst,or as an oxyphilic component of a hybrid support for a platinum-containing electrocatalyst.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
Electrochemical nitrite(NO_(2)^(−))reduction offers a sustainable route for ammonia(NH_(3))synthesis while simultaneously removing contaminants in wastewater.However,its efficiency is often limited by low catalytic ef...Electrochemical nitrite(NO_(2)^(−))reduction offers a sustainable route for ammonia(NH_(3))synthesis while simultaneously removing contaminants in wastewater.However,its efficiency is often limited by low catalytic efficiency and the competitive hydrogen evolution reaction at low NO_(2)^(−)concentrations.Herein,we report an intermittent pulsed electrolysis(IPE)strategy using copper oxide(Cu_(x)O)nanowires,which significantly enhances the NH3 yield rate and Faradaic efficiency(FE)at lower reactant concentrations.In situ experiments and theoretical calculations reveal that alternating between open-circuit and cathodic potentials modulates the copper oxidation states,stabilizing the catalytically active cuprous oxide(Cu_(2)O).Consequently,the IPE approach provides an outstanding NH3 yield rate of 115.10 mg·h^(−1)·cm^(−2)and FE of 91.14%in the presence of 25 mM NO_(2)^(−),markedly outperforming conventional constant potential electrolysis.展开更多
One fundamental question facing electrocatalytic CO_(2)reduction reaction(CO_(2)RR)is how to identify and correlate the local catalyst activity and stability to their bulk performance.Here we develop a versatile scann...One fundamental question facing electrocatalytic CO_(2)reduction reaction(CO_(2)RR)is how to identify and correlate the local catalyst activity and stability to their bulk performance.Here we develop a versatile scanning electrochemical microscopy(SECM)platform to directly analyze catalyst stability,CO_(2)RR product distribution,and chemical environment in complex systems at the microscopic scale.Using two Cu-porphyrin complex isomers as molecular catalysts,we have demonstrated that alternating the Cu-complex catalyst center to asymmetric Cu-N3C structure leads to reduced stability under constant potential electrolysis but increases the electrocatalytic activity under pulsed potential electrolysis.Testing the electroreduction properties of the catalysts in diff erent electrolysis modes,we find alternating electrolysis pattern changes the catalyst product selectivity and the local pH environment at the vicinity of the catalyst surface,which sheds light on the origin of improved hydrocarbon propagation.This work introduces a fast,efficient,and multifunctional SECM technique for evaluating fundamental and mechanistic aspects of CO_(2)RR in situ.展开更多
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National Key Research and Development Program of China(No.2022YFC3901304)the National Natural Science Foundation of China(Nos.52221004,U24A20190,and 52400101).
文摘Enhancing the electrosynthesis of hydrogen peroxide(H_(2)O_(2))(the two-electron oxygen reduction and 2e−ORR)is critical for decentralized and on-site H_(2)O_(2) production.However,the high aeration energy consumption and serious side reactions in the 2e−ORR system have decreased its 2e−ORR performance,hindering its further application.Herein,we greatly reduced the aeration energy consumption using anode-produced O_(2) for the cathode 2e−ORR(anode-cathode coupling)and further decreased the hydrogen evolution reaction(HER)and H_(2)O_(2) electroreduction by applying pulses.A flowthrough reactor with narrow electrode gaps efficiently improves the utilization of anode-produced O_(2).It increased the effluent H_(2)O_(2) concentration by 101.22%compared to non-coupled systems.In addition,pulsed electrolysis increased the effluent H_(2)O_(2) concentration and current efficiency by 3.41 and 11.38 times,respectively.During the power-off period,the electrochemical reaction paused,whereas the O_(2) and H_(2)O_(2) diffusion continued under the concentration gradient.These processes relieve the O_(2) shortage at the cathodes to decrease the HER and alleviate H_(2)O_(2) accumulation at the cathodes,thus reducing its decomposition.Our results provide an easy and efficient way to improve H_(2)O_(2) electrosynthesis performance.
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supports from the National Key R&D program of China(2019YFC1604602)supports from the National Key Basic Research Program of China(2019YFC1906700)the National Natural Science Foundation of China(21876049,51878643)。
文摘Electrochemical transformation emerges as an important solution to sustainable energy conversion and chemical production.Conventional electrolytic systems usually operate under galvanostatic or potentiostatic conditions that sometimes result in unsatisfactory efficiencies or selectivities.Pulse electrolysis by pulsating and programming the potentials/currents can feature unique tunability to the electrodeelectrolyte interface properties that can give rise to drastically different electrochemical behaviors compared to the steady-state counterparts.Although invented almost 100 years ago,pulse electrolysis has received little attention over the period,but has recently attracted a revived focus toward the energyefficient electrolysis.This review will summarize the history and recent efforts of pulse electrolysis in three categories:water electrolysis,CO_(2)electrolysis and other electrolysis.In each section,the advantage of pulse electrolysis over steady-state electrolysis will be discussed in detail,giving a comprehensive overview of the pulse effect on the electrolytic systems.Finally,we will provide our vision of future directions in pulse electrolysis based on previous works.
基金financially supported by the National Natural Science Foundation of China (52173173, 22403047)Natural Science Foundation of Jiangsu Province (BK20220051)+2 种基金Jiangsu Province Carbon Peak and Neutrality Innovation Program (Industry tackling on prospect and key technology) (BE2022031-4, BE2022002-3)The Natural Foundation of Jiangsu Higher Education Institutions of China (23KJB430021)State Key Laboratory of Materials-Oriented Chemical Engineering (No.SKL-MCE-24A16)
文摘Pulsed electrolysis for CO_(2)reduction reaction has emerged as an effective method to enhance catalyst efficiency and optimize product selectivity.However,challenges remain in understanding the mechanisms of surface transformation under pulsed conditions.In this study,using in-situ time-resolved surface-enhanced Raman spectroscopy and differential electrochemical mass spectroscopy,we found local pH at the surface and Cu–O–C species that was generated during the anodic pulse played a key role in pulsed electrolysis.During the pulsed oxidation,an oxidation layer first formed,depleting OH–and lowering the local pH.When the pH was below 8.4,HCO_(3)–transformed the oxidation layer to a nanometer-thick Cu–O–C species,which is a highly reactive catalyst.In the reduction pulse,about 7.4%of the surface Cu–O–C was transformed into CO and CuOx species,enhancing CO_(2)reduction activity.Even in Ar-saturated 0.1 M KHCO_(3),through a Cu–O–C intermediate,a Faradaic efficiency of 0.17%for bicarbonate reduction to CO was observed.Our findings highlight the crucial role of the anodic pulse process in improving CO_(2)reduction activity.
基金supported by the Ministry of Science and Higher Education of the Russian Federation under Project FENN-2024-0002.
文摘Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for productions of materials with well-defined functional properties.Pulse electrolysis,a top-down electrochemical approach,has been demonstrated to be a viable method for producing nanostructured materials with a particular efficacy in the synthesis of tin oxides.This method allows for significant control over the composition and shape of the resulting tin oxides particles by modifying the anionic composition of the aqueous electrolyte,obviating the need for additional capping agents in the synthesis process and eliminating the requirement for high-temperature post-treatments.The composition and microstructural characteristics of these oxides are found to be contingent upon the differing stabilities of tin fluoride and chloride complexes,as well as the distinct mechanisms of interaction between chloride and fluoride anions with an oxidized tin surface,which is influenced by the varying kosmotropic/chaotropic nature of these anions.The composition and microstructural characteristics of the obtained dispersed tin oxides would thus determine their potential applications as an anode material for lithium-ion batteries,as a photocatalyst,or as an oxyphilic component of a hybrid support for a platinum-containing electrocatalyst.
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supported in part by the National Key R&D Program of China(No.2024YFA1509400)the National Natural Science Foundation of China(No.52302094)Natural Science Foundation of Jiangxi,China(No.20232ACB203002).
文摘Electrochemical nitrite(NO_(2)^(−))reduction offers a sustainable route for ammonia(NH_(3))synthesis while simultaneously removing contaminants in wastewater.However,its efficiency is often limited by low catalytic efficiency and the competitive hydrogen evolution reaction at low NO_(2)^(−)concentrations.Herein,we report an intermittent pulsed electrolysis(IPE)strategy using copper oxide(Cu_(x)O)nanowires,which significantly enhances the NH3 yield rate and Faradaic efficiency(FE)at lower reactant concentrations.In situ experiments and theoretical calculations reveal that alternating between open-circuit and cathodic potentials modulates the copper oxidation states,stabilizing the catalytically active cuprous oxide(Cu_(2)O).Consequently,the IPE approach provides an outstanding NH3 yield rate of 115.10 mg·h^(−1)·cm^(−2)and FE of 91.14%in the presence of 25 mM NO_(2)^(−),markedly outperforming conventional constant potential electrolysis.
基金supported by the National Natural Science Foundation of China(22204115,22072101)the Natural Science Foundation of Jiangsu Province(BK20220485)+1 种基金the Suzhou Municipal Science and Technology Bureau(ZXL2022494)the start-up research grant for a distinguished professor at Soochow University(J.H.)。
文摘One fundamental question facing electrocatalytic CO_(2)reduction reaction(CO_(2)RR)is how to identify and correlate the local catalyst activity and stability to their bulk performance.Here we develop a versatile scanning electrochemical microscopy(SECM)platform to directly analyze catalyst stability,CO_(2)RR product distribution,and chemical environment in complex systems at the microscopic scale.Using two Cu-porphyrin complex isomers as molecular catalysts,we have demonstrated that alternating the Cu-complex catalyst center to asymmetric Cu-N3C structure leads to reduced stability under constant potential electrolysis but increases the electrocatalytic activity under pulsed potential electrolysis.Testing the electroreduction properties of the catalysts in diff erent electrolysis modes,we find alternating electrolysis pattern changes the catalyst product selectivity and the local pH environment at the vicinity of the catalyst surface,which sheds light on the origin of improved hydrocarbon propagation.This work introduces a fast,efficient,and multifunctional SECM technique for evaluating fundamental and mechanistic aspects of CO_(2)RR in situ.
