The sluggish reaction kinetics of the oxygen evolution reaction(OER)and methanol oxidation reaction(MOR)remain obstacles to the commercial promotion of water splitting and direct methanol fuel cells.Considering the vi...The sluggish reaction kinetics of the oxygen evolution reaction(OER)and methanol oxidation reaction(MOR)remain obstacles to the commercial promotion of water splitting and direct methanol fuel cells.Considering the vital role of noble metals in electrocatalytic activity,this work focuses on the rational synthesis of Ni-noble metal composite nanocatalysts for overcoming the drawbacks of high cost and susceptible oxidized surfaces of noble metals.The inherent catalytic activity is improved by the altered electronic structure and effective active sites of the catalyst induced by the size effect of noble metal clusters.In particular,a series of Ni-noble metal nanocomposites are successfully synthesized by partially introducing noble metal into Ni with porous interfacial defects derived from Ni-Al layered double hydroxide(LDH).The Ni_(10)Pd_(1)nanocomposite exhibits high OER catalytic activity with an overpotential of 0.279 V at 10 m A/cm^(2),surpassing Ni_(10)Ag_(1)and Ni_(10)Au_(1)counterparts.Furthermore,the average diameter of Pd clusters gradually increases from 5.57 nm to 44.44 nm with the increased proportion of doped Pd,leading to the passivation of catalytic activity due to the exacerbated surface oxidation of Pd in the form of Pd^(2+).After optimization,Ni_(10)Pd_(1)delivers significantly enhanced OER and MOR electroactivities and long-term stability compared to that of Ni_(2)Pd_(1),Ni_(1)Pd_(1)and Ni_(1)Pd_(2),which is conducive to the effective utilization of Pd and alleviation of surface oxidation.展开更多
The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),whi...The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),which relies on the rational regulation of intermediates’binding strength.Herein,we reported a simple strategy to manipulate the adsorption energy of OH^(∗)on electrocatalyst surface via engineering Ni/NbO_(x) heterostructures with manageable oxygen vacancy(Ov).Theoretical calculations confirm that the electronic effect between Ni and NbO_(x) could weaken the hydrogen adsorption on Ni,and the interfacial oxygen vacancy tailor hydroxide binding energy(OHBE).The optimized HBE and OHBE contribute to reduce formation energy of water during the alkaline HOR process.Furthermore,in situ Raman spectroscopy monitor the dynamic process that OH^(∗)adsorbed on oxygen vacancy and react with adjacent H^(∗)adsorbed Ni,confirming the vital role of OH^(∗)for alkaline HOR process.As a result,the optimal Ni/NbO_(x) exhibits a remarkable intrinsic activity with a specific activity of 0.036mA/cm^(2),which is 4-fold than that of pristine Ni counterpart and surpasses most non-precious electrocatalysts ever reported.展开更多
The employment of single atom catalysts(SACs)remarkably increases atomic utilization and catalytic efficiency in various electrochemical processes,especially when coupled with metal clusters/nanoparticles.However,the ...The employment of single atom catalysts(SACs)remarkably increases atomic utilization and catalytic efficiency in various electrochemical processes,especially when coupled with metal clusters/nanoparticles.However,the synergistic effects mainly focus on the energetics of key intermediates during the electrocatalysis,while the properties of electrode surface and electric-double-layer(EDL)structure are largely overlooked.Herein,we report the synthesis of Ru nanoparticles integrated with neighboring Ru single atoms on nitrogen doped carbon(Ru1,n/NC)as efficient catalysts toward hydrogen oxidation reaction(HOR)under alkaline electrolytes.Electrochemical data,in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy,and density functional theory calculations reveal that the positively charged Ru single atoms could lead to the dynamically regulated proportion of strongly hydrogen-bonded interfacial water structure with O-down conformation and optimized connectivity of the hydrogen-bond network in the EDL region,which contribute to the accelerated diffusion of hydroxide ions to the electrified interfaces.Consequently,the obtained Ru1,n/NC catalyst displays remarkable HOR performance with the mass activity of 1.15 mAμgPGM^(-1) under alkaline electrolyte.This work demonstrates the promise of single atoms for interfacial water environment adjustment and mass transfer process modulation,providing new insights into rational design of highly-effective SAC-based electrocatalysts.展开更多
Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uro...Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uronosyltransferases(UATs)to construct glycans containing uronic acids.Despite their biological importance,the synthesis of naturally occurring NDP-uronic acids on a large scale remains challenging.Here,we developed an oxidation reaction insertion strategy for the efficient synthesis of NDP-uronic acids,and 11 NDP-uronic acids were successfully prepared in good yield and on a large scale.The prepared NDP-uronic acids can be used to explore new uronosyltransferases and synthesize uronic acids containing carbohydrates for fundamental research.展开更多
Electrocatalytic glucose oxidation reaction(GOR)has attracted much attention owing to its crucial role in biofuel cell fabrication.Herein,we load MoO_(3)nanoparticles on carbon nanotubes(CNTs)and use a discharge proce...Electrocatalytic glucose oxidation reaction(GOR)has attracted much attention owing to its crucial role in biofuel cell fabrication.Herein,we load MoO_(3)nanoparticles on carbon nanotubes(CNTs)and use a discharge process to prepare a noblemetal-free MC-60 catalyst containing MoO_(3),Mo_(2)C,and a Mo_(2)C–MoO_(3)interface.In the GOR,MC-60 shows activity as high as 745μA/(mmol/L cm^(2)),considerably higher than those of the Pt/CNT(270μA/(mmol/L cm^(2)))and Au/CNT catalysts(110μA/(mmol/L cm^(2))).In the GOR,the response minimum on MC-60 is as low as 8μmol/L,with a steady-state response time of only 3 s.Moreover,MC-60 has superior stability and anti-interference ability to impurities in the GOR.The better performance of MC-60 in the GOR is attributed to the abundant Mo sites bonding to C and O atoms at the MoO_(3)–Mo_(2)C interface.These Mo sites create active sites for promoting glucose adsorption and oxidation,enhancing MC-60 performance in the GOR.Thus,these results help to fabricate more effi cient noble-metal-free catalysts for the fabrication of glucose-based biofuel cells.展开更多
The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalyst...The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.展开更多
Precisely tailoring the surface electronic structures of electrocatalysts for optimal hydrogen binding energy and hydroxide binding energy is vital to improve the sluggish kinetics of hydrogen oxidation reac-tion(HOR)...Precisely tailoring the surface electronic structures of electrocatalysts for optimal hydrogen binding energy and hydroxide binding energy is vital to improve the sluggish kinetics of hydrogen oxidation reac-tion(HOR).Herein,we employ a partial desulfurization strategy to construct a homologous Ru-RuS_(2) heterostructure anchored on hollow mesoporous carbon nanospheres(Ru-RuS_(2)@C).The disparate work functions of the heterostructure contribute to the spontaneous formation of a unique built-in electric field,accelerating charge transfer and boosting conductivity of electrocatalyst.Consequently,Ru-RuS_(2)@C exhibits robust HOR electrocatalytic activity,achieving an exchange current density and mass activity as high as 3.56 mA cm^(-2) and 2.13 mAμg_(Ru)^(-1),respectively.exceeding those of state-of-the-art Pt/C and most contemporary Ru-based HOR electrocatalysts.Surprisingly,Ru-RuS_(2)@C can tolerate 1000 ppm of cO that lacks in Pt/C.Comprehensive analysis reveals that the directional electron transfer across Ru-RuS_(2) heterointerface induces local charge redistribution in interfacial region,which optimizes and balances the adsorption energies of H and OH species,as well as lowers the energy barrier for water formation,thereby promoting theHoR performance.展开更多
Urea oxidation reaction(UOR)is an auxiliary water electrolysis hydrogen production technology developed in recent years to replace oxygen evolution reaction and reduce energy consumption,which can produce hydrogen mor...Urea oxidation reaction(UOR)is an auxiliary water electrolysis hydrogen production technology developed in recent years to replace oxygen evolution reaction and reduce energy consumption,which can produce hydrogen more efficiently by low theoretical potential,reduce the average cost of electrochemical hydrogen production,and is a frontier research hotspot for renewable hydrogen energy.Two-dimensional(2D)nanomaterials as electrocatalysts have many favorable potential,such as it can effectively reduce the resistivity of materials and increase the specific surface area with certainty.This paper reviews the application of 2D materials in UOR in alkaline electrolytes.And a cross-sectional comparison of various material performance data including overpotential,Tafel slope,electrochemical active surface area(ECSA)and it stability test was conducted,which could illustrate the differences between materials composed of different elements.In addition,the main challenges hindering the progress of research on 2D materials in urea electrocatalysis processes and promising materials in this field in future are summarized and prospected.It is believed that this review will contribute to designing and analyzing highperformance 2D urea electrocatalysts for water splitting.展开更多
For treatment of sulfion-containing wastewater,coupling the electrochemical sulfion oxidation reaction(SOR)with hydrogen evolution reaction(HER)can be an ideal way for sulfur and H_(2)resources recovery.Herein,we synt...For treatment of sulfion-containing wastewater,coupling the electrochemical sulfion oxidation reaction(SOR)with hydrogen evolution reaction(HER)can be an ideal way for sulfur and H_(2)resources recovery.Herein,we synthesize a metal-modified carbon nanotube arrays electrode(Co@N-CNTs/CC)for SOR and HER.This electrode has excellent performance for SOR and HER attributed to the unique array structure.It can achieve 99.36 mA/cm^(2)at 0.6 V for SOR,and 10 mA/cm^(2)at 0.067 V for HER.Density functional theory calculations verify that metal modification is able to regulate the electronic structure of carbon nanotube,which is able to optimize the adsorption of intermediates.Employed Co@N-CNTs/CC as bifunctional elec-trodes to establish a hybrid electrolytic cell can reduce about 67%of energy consumption compared with the traditional water splitting electrolytic cell.Finally,the hybrid electrolytic cell is used to treat actual sulfion-containing wastewater,achieving the sulfur yield of 30 mg h^(−1)cm^(−2)and the hydrogen production of 0.64 mL/min.展开更多
Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional therm...Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs.In this study,a mild electrochemical method has been developed as a new approach to induce SMSI,using the cable structured core@shell CNT@SnO_(2) loaded Pt NPs as a proof of concept.The induced SnO_(x) encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in hydrogen oxidation reaction(HOR),and the HOR current density could still maintain 85% for 2000 s with 10,000 ppm CO in H_(2),while the commercial Pt/C is completely inactivated.In addition,the electrons transfer from SnO_(x) to Pt NPs improved the HOR activity of the E-Pt-CNT@SnO_(2),achieving the excellent exchange current density of 1.55 A·mgPt^(-1).In situ Raman spectra and theoretical calculations show that the key to the electrochemical-method-induced SMSI is the formation of defects and the migration of SnO_(x) caused by the electrochemical redox operation,and the weakening the SneO bond strength by Pt NPs.展开更多
Constructing well-defined interfaces in catalysts is a highly effective method to accelerate reactions with multiple intermediates.In this study,we developed a heterostructure catalyst combining fcc NiCu and hcp Ni_(3...Constructing well-defined interfaces in catalysts is a highly effective method to accelerate reactions with multiple intermediates.In this study,we developed a heterostructure catalyst combining fcc NiCu and hcp Ni_(3)N,aiming at achieving superior performance in alkaline hydrogen electrocatalysis.The NiCu/Ni_(3)N not only overcomes the inadequate hydroxyl binding energy performance of NiCu alloys but also solves the problems of insufficient active sites found in most Ni/Ni_(3)N.Experimental results and density functional theoretical calculations reveal that the formation of heterostructure significantly depends on the amount of Cu.This approach effectively prevents the side effects of increased catalyst particle size,typically resulting from the high temperatures and prolonged reaction times required for conventional synthesis of Ni/Ni_(3)N.The interface of this heterostructure induces a distinctive overlapping effect that enhances the adsorption of water and lowers the energy barrier for the rate-determining step.The NiCu/Ni_(3)N catalyst shows an impressive activity of 71.8 mA mg^(-1) at an overpotential of 50 mV,a 14.7 times efficiency enhancement compared to pure Ni and comparable to that of low-loaded commercial Pt/C.This research highlights the potential of NiCu/Ni_(3)N in advancing catalyst development.展开更多
Formic acid oxidation reaction(FAOR),as the anodic reaction in direct formic acid fuel cells,has attracted much attention but increasing the mass activity and stability of catalysts still face a bottleneck to meet the...Formic acid oxidation reaction(FAOR),as the anodic reaction in direct formic acid fuel cells,has attracted much attention but increasing the mass activity and stability of catalysts still face a bottleneck to meet the requirements of practical applications.In the past decades,researchers developed many strategies to fix these issues by improving the structure of catalysts and the newly raised single atom catalysts(SACs)show the high mass activity and stability in FAOR.This review first summarized the reaction mechanism involved in FAOR.The mass activity as well as stability of catalysts reported in the past five years have been outlined.Moreover,the synthetic strategies to improve the catalytic performance of catalysts are also reviewed in this work.Finally,we proposed the research directions to guide the rational design of new FAOR catalysts in the future.展开更多
Corrosion engineering is an effective way to improve the oxygen evolution reaction(OER)activity of al-loys.However,the impact of grain boundary corrosion on the structure and electrochemical performance of alloy is st...Corrosion engineering is an effective way to improve the oxygen evolution reaction(OER)activity of al-loys.However,the impact of grain boundary corrosion on the structure and electrochemical performance of alloy is still unknown.Herein,the vacuum arc-melted CrCoNiFe alloys with interlaced network struc-tures via grain boundary corrosion methods were fabricated.The grain boundaries that existed as de-fects were severely corroded and an interlaced network structure was formed,promoting the exposure of the active site and the release of gas bubbles.Besides,the(oxy)hydroxides layer(25 nm)on the sur-face could act as the true active center and improve the surface wettability.Benefiting from the unique structure and constructed surface,the CrCoNiFe-12 affords a high urea oxidation reaction(UOR)perfor-mance with the lowest overpotential of 250 mV at 10 mA/cm^(2)in 1 M KOH adding 0.33 M urea.The CrCoNiFe-12||Pt only required a cell voltage of 1.485 V to afford 10 mA/cm^(2)for UOR and long-term sta-bility of 100 h at 10 mA/cm^(2)(27.6 mV decrease).These findings offer a facile strategy for designing bulk multiple-principal-element alloy electrodes for energy conversion.展开更多
It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization appli...It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization applications of nano gold catalysts. In this work, some theoretical works on CO adsorp‐tion, O2 adsorption, atomic oxygen adsorption, formation of surface gold oxide films, reaction mechanisms of CO oxidation involving O2 reaction with CO and O2 dissociation before reacting with CO on gold surfaces and Au/metal oxide were summarized, and the influences of coordination number, charge transfer and relativity of gold on CO oxidation reaction were briefly reviewed. It was found that CO reaction mechanism depended on the systems with or without oxide and the strong relativistic effects might play an important role in CO oxidation reaction on gold catalysts. In particular, the relativistic effects are related to the unique behaviors of CO adsorption, O adsorption, O2 activation on gold surfaces, effects of coordination number and the wide gap between the chem‐ical inertness of bulk gold and high catalytic activity of nano gold. The present work helps us to understand the CO oxidation reaction mechanism on gold catalysts and the influence of relativistic effects on gold catalysis.展开更多
Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)in fuel cells.Maximizing the utilization of Pt based materials by modulating their m...Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)in fuel cells.Maximizing the utilization of Pt based materials by modulating their morphologies to expose more active sites is a fundamental objective for the practical application of fuel cells.Herein,we report a new class of hierarchically skeletal Pt-Ni nanocrystals(HSNs)with a multi-layered structure,prepared by an inorganic acid-induced solvothermal method.The addition of H_(2)SO_(4)to the synthetic protocol provides a critical trigger for the successful growth of Pt-Ni nanocrystals with the desired structure.The Pt-Ni HSNs synthesized by this method exhibit enhanced mass activity of 1.25 A mgpt−1 at 0.9 V(versus the reversible hydrogen electrode)towards ORR in 0.1-M HClO_(4),which is superior to that of Pt-Ni multi-branched nanocrystals obtained by the same method in the absence of inorganic acid;it is additionally 8.9-fold higher than that of the commercial Pt/C catalyst.Meanwhile,it displays enhanced stability,with only 21.6%mass activity loss after 10,000 cycles(0.6–1.0 V)for ORR.Furthermore,the Pt-Ni HSNs show enhanced activity and anti-toxic ability in CO for MOR.The superb activity of the Pt-Ni HSNs for ORR and MOR is fully attributed to an extensively exposed electrochemical surface area and high intrinsic activity,induced by strain effects,provided by the unique hierarchically skeletal alloy structure.The novel open and hierarchical structure of Pt-Ni alloy provides a promising approach for significant improvements of the activity of Pt based alloy electrocatalysts.展开更多
An experiment for the oxidation process of single magnetite pellet and theoretical analysis based on modi lied unreacted core shrinking （MUCS） model were carried out, and the controlling mechanisms of the initial an...An experiment for the oxidation process of single magnetite pellet and theoretical analysis based on modi lied unreacted core shrinking （MUCS） model were carried out, and the controlling mechanisms of the initial and de veloping reactions were examined, respectively. From the study of the initial reaction, it was found that the chemical reaction of surface is the controlling step of the overall reaction when the temperature is up to about 750 K, while the mass transfer through the gaseous boundary layer dominates the reaction rate when the temperature is above 750 K. As the reaction developing within the pellet, the mass transfer through the produced layer becomes the controlling step. In addition, the effects of reaction conditions （such as oxygen concentration, temperature） on the fractional oxidation of magnetite pellet were determined.展开更多
Exploring effective, durable, and affordable electrocatalysts of methanol oxidation reaction(MOR) is of vital significance for the industrial application of direct methanol fuel cells. Herein, an efficient, general,an...Exploring effective, durable, and affordable electrocatalysts of methanol oxidation reaction(MOR) is of vital significance for the industrial application of direct methanol fuel cells. Herein, an efficient, general,and expandable method is developed to synthesis two-dimensional(2D) ternary Pt Bi M nanoplates(NPLs), in which various M(Co, Ni, Cu, Zn, Sn) is severed as the third component to the binary Pt Bi system. The MOR performance of Pt Bi M NPLs is entirely investigated, demonstrating that both the MOR activity and durability is enhanced with the introduction of the additional composition. Pt3Bi3Zn NPLs shows much higher MOR activity and stability than that of the Pt Bi counterparts, not to mention the current advanced Pt Ru/C and Pt/C catalysts. The prominent performances are attributed to the modulated electronic structure of the surface Pt in Pt Bi NPLs by the addition of Zn, resulting in a weakened affination between Pt and the adsorbed poisoning species(mainly CO) compared with Pt Bi NPLs, verified by density functional theory(DFT) calculations. In addition, the absorbed OH can be generated on the surface of Zn atom due to its favorable water activation properties, thus the CO removal on the adjacent Pt atoms is accelerated, further leading to a high activity and anti-poisoning performance of the resulting Pt_(3)Bi_(3)Zn catalyst. This work provides new insights and robust strategy for highly efficient MOR electrocatalyst with extraordinary anti-poisoning performance and stability.展开更多
Urea oxidation reaction (UOR),which has favorable thermodynamic energy barriers compared with oxygen evolution reaction (OER),can provide more cost-effective electrons for the renewable energy systems,but is trapped b...Urea oxidation reaction (UOR),which has favorable thermodynamic energy barriers compared with oxygen evolution reaction (OER),can provide more cost-effective electrons for the renewable energy systems,but is trapped by its sluggish UOR kinetics and intricate reaction intermediates formation/desorption process.Herein,we report a novel and effective electrocatalyst consisting of carbon cloth supported nitrogen vacancies-enriched Ce-doped Ni_(3)N hierarchical nanosheets (Ce-Ni_(3)N @CC) to optimize the flat-footed UOR kinetics,especially the stiff rate-determine CO_(2)desorption step of UOR.Upon the introduction of valance state variable Ce,the resultant nitrogen vacancies enriched Ce-Ni_(3)N @CC exhibits an enhanced UOR performance where the operation voltage requires only 1.31 V to deliver the current density of 10 mA cm^(-2),which is superior to that of Ni_(3)N @CC catalyst (1.36 V) and other counterparts.Density functional theory (DFT) results demonstrate that the incorporation of Ce in Ni_(3)N lowers the formation energy of nitrogen vacancies,resulting in rich nitrogen vacancies in Ce-Ni_(3)N @CC.Moreover,the nitrogen vacancies together with Ce doping optimize the local charge distribution around Ni sites,and balance the adsorption energy of CO_(2)in the rate-determining step (RDS),as well as affect the initial adsorption structure of urea,leading to the superior UOR catalytic performance of Ce-Ni_(3)N @CC.When integrating the Ce-Ni_(3)N catalyst in UOR//HER and UOR//CO_(2)R flow electrolyzer,both of them perform well with low operation voltage and robust long-term stability,proofing that the thermodynamically favorable UOR can act as a suitable substitute anodic reaction compared with that of OER.Our findings here not only provide a novel UOR catalyst but also offer a promising design strategy for the future development of energy-related devices.展开更多
The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR ...The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR kinetics in alkaline is two to three orders of magnitude slower than that in acid.More critically,fundamental understanding of the sluggish kinetics derived from the p H effect is still debatable.In this review,the recent development of understanding HOR mechanism and rational design of advanced HOR electrocatalysts are summarized.First,recent advances in the theories focusing on fundamental understandings of HOR under alkaline electrolyte are comprehensively discussed.Then,from the aspect of intermediates binding energy,optimizing hydrogen binding energy(HBE)and increasing hydroxyl binding energy(OHBE),the strategies for designing efficient alkaline HOR catalysts are summarized.At last,perspectives for the future research on alkaline HOR are pointed out.展开更多
Bimetallic Pt-based catalysts have been extensively investigated to enhance the performance of direct methanol fuel cells(DMFCs) because CO, a by-product, reduces the activity of the pure Pt catalysts. Herein, we synt...Bimetallic Pt-based catalysts have been extensively investigated to enhance the performance of direct methanol fuel cells(DMFCs) because CO, a by-product, reduces the activity of the pure Pt catalysts. Herein, we synthesized Pt-Pb hexagonal nanoplates as a model catalyst for the methanol oxidation reaction(MOR) and further controlled the Pt and Pb distributions on the surface of the nanoplates through acetic acid(HAc) treatment. As a result, we obtained Pt-Pb nanoplates and HAc-treated Pt-Pb nanoplates with homogeneous and heterogeneous distributions of the Pt-Pb alloy surfaces, respectively. We showed that the MOR activity and stability of the Pt-Pb nanoplates improved compared to those of the HAc-treated Pt-Pb nanoplates, mainly due to the enhanced CO tolerance and the modified electronic structure of Pt under the influence of the oxophilic Pb.展开更多
基金support by the National Natural Science Foundation of China(Nos.U20A20123,51874357,22379166)Natural Science Foundation for Distinguished Young Scholars of Hunan Province(No.2022JJ10089)。
文摘The sluggish reaction kinetics of the oxygen evolution reaction(OER)and methanol oxidation reaction(MOR)remain obstacles to the commercial promotion of water splitting and direct methanol fuel cells.Considering the vital role of noble metals in electrocatalytic activity,this work focuses on the rational synthesis of Ni-noble metal composite nanocatalysts for overcoming the drawbacks of high cost and susceptible oxidized surfaces of noble metals.The inherent catalytic activity is improved by the altered electronic structure and effective active sites of the catalyst induced by the size effect of noble metal clusters.In particular,a series of Ni-noble metal nanocomposites are successfully synthesized by partially introducing noble metal into Ni with porous interfacial defects derived from Ni-Al layered double hydroxide(LDH).The Ni_(10)Pd_(1)nanocomposite exhibits high OER catalytic activity with an overpotential of 0.279 V at 10 m A/cm^(2),surpassing Ni_(10)Ag_(1)and Ni_(10)Au_(1)counterparts.Furthermore,the average diameter of Pd clusters gradually increases from 5.57 nm to 44.44 nm with the increased proportion of doped Pd,leading to the passivation of catalytic activity due to the exacerbated surface oxidation of Pd in the form of Pd^(2+).After optimization,Ni_(10)Pd_(1)delivers significantly enhanced OER and MOR electroactivities and long-term stability compared to that of Ni_(2)Pd_(1),Ni_(1)Pd_(1)and Ni_(1)Pd_(2),which is conducive to the effective utilization of Pd and alleviation of surface oxidation.
基金supported by Jilin Province Science and Technology Development Program(Nos.20200201001JC,20210502002ZP,20230101367JC,20220301011GX)Jilin Province Science and Technology Major Project(No.222648GX0105103875).
文摘The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),which relies on the rational regulation of intermediates’binding strength.Herein,we reported a simple strategy to manipulate the adsorption energy of OH^(∗)on electrocatalyst surface via engineering Ni/NbO_(x) heterostructures with manageable oxygen vacancy(Ov).Theoretical calculations confirm that the electronic effect between Ni and NbO_(x) could weaken the hydrogen adsorption on Ni,and the interfacial oxygen vacancy tailor hydroxide binding energy(OHBE).The optimized HBE and OHBE contribute to reduce formation energy of water during the alkaline HOR process.Furthermore,in situ Raman spectroscopy monitor the dynamic process that OH^(∗)adsorbed on oxygen vacancy and react with adjacent H^(∗)adsorbed Ni,confirming the vital role of OH^(∗)for alkaline HOR process.As a result,the optimal Ni/NbO_(x) exhibits a remarkable intrinsic activity with a specific activity of 0.036mA/cm^(2),which is 4-fold than that of pristine Ni counterpart and surpasses most non-precious electrocatalysts ever reported.
文摘The employment of single atom catalysts(SACs)remarkably increases atomic utilization and catalytic efficiency in various electrochemical processes,especially when coupled with metal clusters/nanoparticles.However,the synergistic effects mainly focus on the energetics of key intermediates during the electrocatalysis,while the properties of electrode surface and electric-double-layer(EDL)structure are largely overlooked.Herein,we report the synthesis of Ru nanoparticles integrated with neighboring Ru single atoms on nitrogen doped carbon(Ru1,n/NC)as efficient catalysts toward hydrogen oxidation reaction(HOR)under alkaline electrolytes.Electrochemical data,in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy,and density functional theory calculations reveal that the positively charged Ru single atoms could lead to the dynamically regulated proportion of strongly hydrogen-bonded interfacial water structure with O-down conformation and optimized connectivity of the hydrogen-bond network in the EDL region,which contribute to the accelerated diffusion of hydroxide ions to the electrified interfaces.Consequently,the obtained Ru1,n/NC catalyst displays remarkable HOR performance with the mass activity of 1.15 mAμgPGM^(-1) under alkaline electrolyte.This work demonstrates the promise of single atoms for interfacial water environment adjustment and mass transfer process modulation,providing new insights into rational design of highly-effective SAC-based electrocatalysts.
基金financially supported by National Natural Science Foundation of China(No.22207113 to J.Zhang)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110588to J.Zhang)Natural Science Foundation of Shanghai Municipality(No.22ZR1474000 to L.Wen)。
文摘Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uronosyltransferases(UATs)to construct glycans containing uronic acids.Despite their biological importance,the synthesis of naturally occurring NDP-uronic acids on a large scale remains challenging.Here,we developed an oxidation reaction insertion strategy for the efficient synthesis of NDP-uronic acids,and 11 NDP-uronic acids were successfully prepared in good yield and on a large scale.The prepared NDP-uronic acids can be used to explore new uronosyltransferases and synthesize uronic acids containing carbohydrates for fundamental research.
基金supported by the National Natural Science Foundation of China(Nos.82170426 and 22078193)Double Thousand Plan of Jiangxi Province(Nos.461654,jxsq2019102052).
文摘Electrocatalytic glucose oxidation reaction(GOR)has attracted much attention owing to its crucial role in biofuel cell fabrication.Herein,we load MoO_(3)nanoparticles on carbon nanotubes(CNTs)and use a discharge process to prepare a noblemetal-free MC-60 catalyst containing MoO_(3),Mo_(2)C,and a Mo_(2)C–MoO_(3)interface.In the GOR,MC-60 shows activity as high as 745μA/(mmol/L cm^(2)),considerably higher than those of the Pt/CNT(270μA/(mmol/L cm^(2)))and Au/CNT catalysts(110μA/(mmol/L cm^(2))).In the GOR,the response minimum on MC-60 is as low as 8μmol/L,with a steady-state response time of only 3 s.Moreover,MC-60 has superior stability and anti-interference ability to impurities in the GOR.The better performance of MC-60 in the GOR is attributed to the abundant Mo sites bonding to C and O atoms at the MoO_(3)–Mo_(2)C interface.These Mo sites create active sites for promoting glucose adsorption and oxidation,enhancing MC-60 performance in the GOR.Thus,these results help to fabricate more effi cient noble-metal-free catalysts for the fabrication of glucose-based biofuel cells.
基金financially supported by the National Natural Science Foundation of China (52200076,22169005,52370057)the Growth Project of Young Scientific and Technological Talents in General Colleges and Universities in Guizhou Province ([2022]143)+4 种基金the Science and Technology Foundation of Guizhou Province ([2022]109)the Natural Science Special Foundation of Guizhou University (202017,702775203301)the Natural Science Foundation of Chongqing (CSTB2022NSCQ-BHX0035)the Special Research Assistant Program of Chinese Academy of Sciencethe Research Foundation of Chongqing University of Science and Technology (ckrc2022026)。
文摘The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.
基金financially supported by the National Natural Science Foundation of China (52363028)the Natural Science Foundation of Guangxi Province (2021GXNSFAA076001)the Guangxi Technology Base and Talent Subject (GUIKE AD23023004,GUIKE AD20297039)
文摘Precisely tailoring the surface electronic structures of electrocatalysts for optimal hydrogen binding energy and hydroxide binding energy is vital to improve the sluggish kinetics of hydrogen oxidation reac-tion(HOR).Herein,we employ a partial desulfurization strategy to construct a homologous Ru-RuS_(2) heterostructure anchored on hollow mesoporous carbon nanospheres(Ru-RuS_(2)@C).The disparate work functions of the heterostructure contribute to the spontaneous formation of a unique built-in electric field,accelerating charge transfer and boosting conductivity of electrocatalyst.Consequently,Ru-RuS_(2)@C exhibits robust HOR electrocatalytic activity,achieving an exchange current density and mass activity as high as 3.56 mA cm^(-2) and 2.13 mAμg_(Ru)^(-1),respectively.exceeding those of state-of-the-art Pt/C and most contemporary Ru-based HOR electrocatalysts.Surprisingly,Ru-RuS_(2)@C can tolerate 1000 ppm of cO that lacks in Pt/C.Comprehensive analysis reveals that the directional electron transfer across Ru-RuS_(2) heterointerface induces local charge redistribution in interfacial region,which optimizes and balances the adsorption energies of H and OH species,as well as lowers the energy barrier for water formation,thereby promoting theHoR performance.
基金financially supported by the National Key Research and Development Program of China(No.2020YFB1713500)the Major Science and Technology Projects of Henan Province(No.221100230200)+3 种基金Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.23IRTSTHN009)the Project of Science and Technology Department of Henan Province(Nos.232102241034 and 222102240074)the Natural Science Foundation of Suzhou University of Science and Technology(No.XKQ2020002)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.22KJB530009)。
文摘Urea oxidation reaction(UOR)is an auxiliary water electrolysis hydrogen production technology developed in recent years to replace oxygen evolution reaction and reduce energy consumption,which can produce hydrogen more efficiently by low theoretical potential,reduce the average cost of electrochemical hydrogen production,and is a frontier research hotspot for renewable hydrogen energy.Two-dimensional(2D)nanomaterials as electrocatalysts have many favorable potential,such as it can effectively reduce the resistivity of materials and increase the specific surface area with certainty.This paper reviews the application of 2D materials in UOR in alkaline electrolytes.And a cross-sectional comparison of various material performance data including overpotential,Tafel slope,electrochemical active surface area(ECSA)and it stability test was conducted,which could illustrate the differences between materials composed of different elements.In addition,the main challenges hindering the progress of research on 2D materials in urea electrocatalysis processes and promising materials in this field in future are summarized and prospected.It is believed that this review will contribute to designing and analyzing highperformance 2D urea electrocatalysts for water splitting.
基金supported by Natural Science Foundation of Shandong Province(Nos.ZR2022QE076,ZR2021JQ15,ZR2019YQ20)the National Natural Science Foundation of China(Nos.52002145,52202092,51972147,52022037)Taishan Scholars Project Special Funds(No.tsqn201812083).
文摘For treatment of sulfion-containing wastewater,coupling the electrochemical sulfion oxidation reaction(SOR)with hydrogen evolution reaction(HER)can be an ideal way for sulfur and H_(2)resources recovery.Herein,we synthesize a metal-modified carbon nanotube arrays electrode(Co@N-CNTs/CC)for SOR and HER.This electrode has excellent performance for SOR and HER attributed to the unique array structure.It can achieve 99.36 mA/cm^(2)at 0.6 V for SOR,and 10 mA/cm^(2)at 0.067 V for HER.Density functional theory calculations verify that metal modification is able to regulate the electronic structure of carbon nanotube,which is able to optimize the adsorption of intermediates.Employed Co@N-CNTs/CC as bifunctional elec-trodes to establish a hybrid electrolytic cell can reduce about 67%of energy consumption compared with the traditional water splitting electrolytic cell.Finally,the hybrid electrolytic cell is used to treat actual sulfion-containing wastewater,achieving the sulfur yield of 30 mg h^(−1)cm^(−2)and the hydrogen production of 0.64 mL/min.
基金the“National Natural Science Foundation of China(No.22122202)”.
文摘Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs.In this study,a mild electrochemical method has been developed as a new approach to induce SMSI,using the cable structured core@shell CNT@SnO_(2) loaded Pt NPs as a proof of concept.The induced SnO_(x) encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in hydrogen oxidation reaction(HOR),and the HOR current density could still maintain 85% for 2000 s with 10,000 ppm CO in H_(2),while the commercial Pt/C is completely inactivated.In addition,the electrons transfer from SnO_(x) to Pt NPs improved the HOR activity of the E-Pt-CNT@SnO_(2),achieving the excellent exchange current density of 1.55 A·mgPt^(-1).In situ Raman spectra and theoretical calculations show that the key to the electrochemical-method-induced SMSI is the formation of defects and the migration of SnO_(x) caused by the electrochemical redox operation,and the weakening the SneO bond strength by Pt NPs.
文摘Constructing well-defined interfaces in catalysts is a highly effective method to accelerate reactions with multiple intermediates.In this study,we developed a heterostructure catalyst combining fcc NiCu and hcp Ni_(3)N,aiming at achieving superior performance in alkaline hydrogen electrocatalysis.The NiCu/Ni_(3)N not only overcomes the inadequate hydroxyl binding energy performance of NiCu alloys but also solves the problems of insufficient active sites found in most Ni/Ni_(3)N.Experimental results and density functional theoretical calculations reveal that the formation of heterostructure significantly depends on the amount of Cu.This approach effectively prevents the side effects of increased catalyst particle size,typically resulting from the high temperatures and prolonged reaction times required for conventional synthesis of Ni/Ni_(3)N.The interface of this heterostructure induces a distinctive overlapping effect that enhances the adsorption of water and lowers the energy barrier for the rate-determining step.The NiCu/Ni_(3)N catalyst shows an impressive activity of 71.8 mA mg^(-1) at an overpotential of 50 mV,a 14.7 times efficiency enhancement compared to pure Ni and comparable to that of low-loaded commercial Pt/C.This research highlights the potential of NiCu/Ni_(3)N in advancing catalyst development.
基金Project(22102218)supported by the National Natural Science Foundation of ChinaProject(2022RC1110)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2022QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,China。
文摘Formic acid oxidation reaction(FAOR),as the anodic reaction in direct formic acid fuel cells,has attracted much attention but increasing the mass activity and stability of catalysts still face a bottleneck to meet the requirements of practical applications.In the past decades,researchers developed many strategies to fix these issues by improving the structure of catalysts and the newly raised single atom catalysts(SACs)show the high mass activity and stability in FAOR.This review first summarized the reaction mechanism involved in FAOR.The mass activity as well as stability of catalysts reported in the past five years have been outlined.Moreover,the synthetic strategies to improve the catalytic performance of catalysts are also reviewed in this work.Finally,we proposed the research directions to guide the rational design of new FAOR catalysts in the future.
基金supported by the National Natu-ral Science Foundation of China(No.52102210)the Natural Sci-ence Foundation of Sichuan Province(Nos.2022NSFSC2005 and 2022NSFSC1255)+1 种基金the Opening Project of Key Laboratory of Op-toelectronic Chemical Materials and Devices of Ministry of Educa-tion,Jianghan University(No.JDGD-202218)Supplementary materials Supplementary material associated with this article can be found,in the online version,at doi:10.1016/j.jmst.2024.01.096.106。
文摘Corrosion engineering is an effective way to improve the oxygen evolution reaction(OER)activity of al-loys.However,the impact of grain boundary corrosion on the structure and electrochemical performance of alloy is still unknown.Herein,the vacuum arc-melted CrCoNiFe alloys with interlaced network struc-tures via grain boundary corrosion methods were fabricated.The grain boundaries that existed as de-fects were severely corroded and an interlaced network structure was formed,promoting the exposure of the active site and the release of gas bubbles.Besides,the(oxy)hydroxides layer(25 nm)on the sur-face could act as the true active center and improve the surface wettability.Benefiting from the unique structure and constructed surface,the CrCoNiFe-12 affords a high urea oxidation reaction(UOR)perfor-mance with the lowest overpotential of 250 mV at 10 mA/cm^(2)in 1 M KOH adding 0.33 M urea.The CrCoNiFe-12||Pt only required a cell voltage of 1.485 V to afford 10 mA/cm^(2)for UOR and long-term sta-bility of 100 h at 10 mA/cm^(2)(27.6 mV decrease).These findings offer a facile strategy for designing bulk multiple-principal-element alloy electrodes for energy conversion.
基金supported by the National Natural Science Foundation of China (21103165)
文摘It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization applications of nano gold catalysts. In this work, some theoretical works on CO adsorp‐tion, O2 adsorption, atomic oxygen adsorption, formation of surface gold oxide films, reaction mechanisms of CO oxidation involving O2 reaction with CO and O2 dissociation before reacting with CO on gold surfaces and Au/metal oxide were summarized, and the influences of coordination number, charge transfer and relativity of gold on CO oxidation reaction were briefly reviewed. It was found that CO reaction mechanism depended on the systems with or without oxide and the strong relativistic effects might play an important role in CO oxidation reaction on gold catalysts. In particular, the relativistic effects are related to the unique behaviors of CO adsorption, O adsorption, O2 activation on gold surfaces, effects of coordination number and the wide gap between the chem‐ical inertness of bulk gold and high catalytic activity of nano gold. The present work helps us to understand the CO oxidation reaction mechanism on gold catalysts and the influence of relativistic effects on gold catalysis.
文摘Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)in fuel cells.Maximizing the utilization of Pt based materials by modulating their morphologies to expose more active sites is a fundamental objective for the practical application of fuel cells.Herein,we report a new class of hierarchically skeletal Pt-Ni nanocrystals(HSNs)with a multi-layered structure,prepared by an inorganic acid-induced solvothermal method.The addition of H_(2)SO_(4)to the synthetic protocol provides a critical trigger for the successful growth of Pt-Ni nanocrystals with the desired structure.The Pt-Ni HSNs synthesized by this method exhibit enhanced mass activity of 1.25 A mgpt−1 at 0.9 V(versus the reversible hydrogen electrode)towards ORR in 0.1-M HClO_(4),which is superior to that of Pt-Ni multi-branched nanocrystals obtained by the same method in the absence of inorganic acid;it is additionally 8.9-fold higher than that of the commercial Pt/C catalyst.Meanwhile,it displays enhanced stability,with only 21.6%mass activity loss after 10,000 cycles(0.6–1.0 V)for ORR.Furthermore,the Pt-Ni HSNs show enhanced activity and anti-toxic ability in CO for MOR.The superb activity of the Pt-Ni HSNs for ORR and MOR is fully attributed to an extensively exposed electrochemical surface area and high intrinsic activity,induced by strain effects,provided by the unique hierarchically skeletal alloy structure.The novel open and hierarchical structure of Pt-Ni alloy provides a promising approach for significant improvements of the activity of Pt based alloy electrocatalysts.
基金Sponsored by National Natural Science Foundation of China(59374166,11072057)
文摘An experiment for the oxidation process of single magnetite pellet and theoretical analysis based on modi lied unreacted core shrinking （MUCS） model were carried out, and the controlling mechanisms of the initial and de veloping reactions were examined, respectively. From the study of the initial reaction, it was found that the chemical reaction of surface is the controlling step of the overall reaction when the temperature is up to about 750 K, while the mass transfer through the gaseous boundary layer dominates the reaction rate when the temperature is above 750 K. As the reaction developing within the pellet, the mass transfer through the produced layer becomes the controlling step. In addition, the effects of reaction conditions （such as oxygen concentration, temperature） on the fractional oxidation of magnetite pellet were determined.
基金supported by the Hainan Province Science and Technology Special Fund(ZDYF2020037,2020207)the National Natural Science Foundation of China(21805104,22109034,22109035,52164028,62105083)+3 种基金the Basic and Applied Basic Research Foundation of Guangdong Province(2019A1515110558)the Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province(202021)the Innovative Research Projects for Graduate Students of Hainan Province(Qhys2021-134)the Start-up Research Foundation of Hainan University(KYQD(ZR)-20008,20082,20083,20084,21065,21124,21125)。
文摘Exploring effective, durable, and affordable electrocatalysts of methanol oxidation reaction(MOR) is of vital significance for the industrial application of direct methanol fuel cells. Herein, an efficient, general,and expandable method is developed to synthesis two-dimensional(2D) ternary Pt Bi M nanoplates(NPLs), in which various M(Co, Ni, Cu, Zn, Sn) is severed as the third component to the binary Pt Bi system. The MOR performance of Pt Bi M NPLs is entirely investigated, demonstrating that both the MOR activity and durability is enhanced with the introduction of the additional composition. Pt3Bi3Zn NPLs shows much higher MOR activity and stability than that of the Pt Bi counterparts, not to mention the current advanced Pt Ru/C and Pt/C catalysts. The prominent performances are attributed to the modulated electronic structure of the surface Pt in Pt Bi NPLs by the addition of Zn, resulting in a weakened affination between Pt and the adsorbed poisoning species(mainly CO) compared with Pt Bi NPLs, verified by density functional theory(DFT) calculations. In addition, the absorbed OH can be generated on the surface of Zn atom due to its favorable water activation properties, thus the CO removal on the adjacent Pt atoms is accelerated, further leading to a high activity and anti-poisoning performance of the resulting Pt_(3)Bi_(3)Zn catalyst. This work provides new insights and robust strategy for highly efficient MOR electrocatalyst with extraordinary anti-poisoning performance and stability.
基金financially supported by the National Natural Science Foundation of China (22109073, 22072067 and 21875112)the supports from National and Local Joint Engineering Research Center of Biomedical Functional Materialsa project sponsored by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Urea oxidation reaction (UOR),which has favorable thermodynamic energy barriers compared with oxygen evolution reaction (OER),can provide more cost-effective electrons for the renewable energy systems,but is trapped by its sluggish UOR kinetics and intricate reaction intermediates formation/desorption process.Herein,we report a novel and effective electrocatalyst consisting of carbon cloth supported nitrogen vacancies-enriched Ce-doped Ni_(3)N hierarchical nanosheets (Ce-Ni_(3)N @CC) to optimize the flat-footed UOR kinetics,especially the stiff rate-determine CO_(2)desorption step of UOR.Upon the introduction of valance state variable Ce,the resultant nitrogen vacancies enriched Ce-Ni_(3)N @CC exhibits an enhanced UOR performance where the operation voltage requires only 1.31 V to deliver the current density of 10 mA cm^(-2),which is superior to that of Ni_(3)N @CC catalyst (1.36 V) and other counterparts.Density functional theory (DFT) results demonstrate that the incorporation of Ce in Ni_(3)N lowers the formation energy of nitrogen vacancies,resulting in rich nitrogen vacancies in Ce-Ni_(3)N @CC.Moreover,the nitrogen vacancies together with Ce doping optimize the local charge distribution around Ni sites,and balance the adsorption energy of CO_(2)in the rate-determining step (RDS),as well as affect the initial adsorption structure of urea,leading to the superior UOR catalytic performance of Ce-Ni_(3)N @CC.When integrating the Ce-Ni_(3)N catalyst in UOR//HER and UOR//CO_(2)R flow electrolyzer,both of them perform well with low operation voltage and robust long-term stability,proofing that the thermodynamically favorable UOR can act as a suitable substitute anodic reaction compared with that of OER.Our findings here not only provide a novel UOR catalyst but also offer a promising design strategy for the future development of energy-related devices.
基金financially supported by the National Key Research and Development program of China(2018YFB1502302)the National Natural Science Foundation of China(21972107)+1 种基金the Natural Science Foundation of Hubei Province(2020CFA095)the Natural Science Foundation of Jiangsu Province(BK20191186)。
文摘The development of highly efficient electrocatalysts toward hydrogen oxidation reaction(HOR)under alkaline media is essential for the commercialization of alkaline exchange membrane fuel cells(AEMFCs).However,the HOR kinetics in alkaline is two to three orders of magnitude slower than that in acid.More critically,fundamental understanding of the sluggish kinetics derived from the p H effect is still debatable.In this review,the recent development of understanding HOR mechanism and rational design of advanced HOR electrocatalysts are summarized.First,recent advances in the theories focusing on fundamental understandings of HOR under alkaline electrolyte are comprehensively discussed.Then,from the aspect of intermediates binding energy,optimizing hydrogen binding energy(HBE)and increasing hydroxyl binding energy(OHBE),the strategies for designing efficient alkaline HOR catalysts are summarized.At last,perspectives for the future research on alkaline HOR are pointed out.
文摘Bimetallic Pt-based catalysts have been extensively investigated to enhance the performance of direct methanol fuel cells(DMFCs) because CO, a by-product, reduces the activity of the pure Pt catalysts. Herein, we synthesized Pt-Pb hexagonal nanoplates as a model catalyst for the methanol oxidation reaction(MOR) and further controlled the Pt and Pb distributions on the surface of the nanoplates through acetic acid(HAc) treatment. As a result, we obtained Pt-Pb nanoplates and HAc-treated Pt-Pb nanoplates with homogeneous and heterogeneous distributions of the Pt-Pb alloy surfaces, respectively. We showed that the MOR activity and stability of the Pt-Pb nanoplates improved compared to those of the HAc-treated Pt-Pb nanoplates, mainly due to the enhanced CO tolerance and the modified electronic structure of Pt under the influence of the oxophilic Pb.
