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
Storing hydrogen in green methanol is a well-known and cost-effective way for long-term energy storage.However,using green methanol in fuel cell technologies requires electrocatalysts with superior resistance to poiso...Storing hydrogen in green methanol is a well-known and cost-effective way for long-term energy storage.However,using green methanol in fuel cell technologies requires electrocatalysts with superior resistance to poisoning induced by intermediate species.This study introduces a new class of palladium-based rare earth(RE)alloys with exceptional resistance to methanol for the oxygen reduction reaction(ORR)and outstanding resistance to carbon monoxide poisoning for the hydrogen oxidation reaction(HOR).The PdEr catalyst achieved unparalleled ORR activity amongst the Pd-based rare earth alloys and demonstrated remarkable resistance to methanol poisoning,which is two orders of magnitude higher than commercial Pt/C catalysts.Furthermore,the PdEr catalyst shows high hydrogen oxidation activity under 100 ppm CO.Comprehensive analysis demonstrates that the RE element-enriched sublayer tuning of the Pd-skin's surface strain is responsible for the enhanced ORR and HOR capabilities.This modification allows for precise control over the adsorption strength of critical intermediates while concurrently diminishing the adsorption energy of methanol and CO on the PdEr surface.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
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
Anion exchange membrane(AEM)fuel cells have gained great attention partially due to the advantage of using non-precious metal as catalysts.However,the reaction kinetics of hydrogen oxidation reaction(HOR)is two orders...Anion exchange membrane(AEM)fuel cells have gained great attention partially due to the advantage of using non-precious metal as catalysts.However,the reaction kinetics of hydrogen oxidation reaction(HOR)is two orders of magnitude slower in alkaline systems than in acid.To understand the slower kinetics of HOR in base,two major theories have been proposed,such as(1)pH dependent hydrogen binding energy as a major descriptor for HOR;and(2)bifunctional theory based on the contributions of both hydrogen and hydroxide adsorption for HOR in alkaline electrolyte.Here,we discuss the possible HOR mechanisms in alkaline electrolytes with the corresponding change in their Tafel behavior.Apart from the traditional Tafel-Volmer and Heyrovsky-Volmer HOR mechanisms,the recently proposed hydroxide adsorption step is also discussed to illustrate the difference in HOR mechanisms in acid and base.We further summarize the representative works of alkaline HOR catalyst design(e.g.,precious metals,alloy,intermetallic materials,Ni-based alloys,carbides,nitrides,etc.),and briefly describe their fundamental HOR reaction mechanism to emphasize the difference in elementary reaction steps in alkaline medium.The strategy of strengthening local interaction that facilitates both H2 desorption and Hads+OHads recombination is finally proposed for future HOR catalyst design in alkaline environment.展开更多
Developing highly efficient platinum‐group‐metal‐free electrocatalysts towards hydrogen oxidation reaction(HOR)under alkaline electrolyte is critical for the development of alkaline exchange member fuel cells.Herei...Developing highly efficient platinum‐group‐metal‐free electrocatalysts towards hydrogen oxidation reaction(HOR)under alkaline electrolyte is critical for the development of alkaline exchange member fuel cells.Herein,we reported the synthesis of boron doped Ni electrocatalyst(B‐Ni/C)and its remarkable alkaline HOR performance,with a 10‐fold mass activity enhancement compared with that of undoped Ni catalyst.Experimental results and density functional theory calculations indicate the d‐p hybridization between the p orbital of B and the d orbital of Ni via B‐doping could lead to promoted OH adsorption and optimized hydrogen binding energy on Ni surface,which together with the reduced formation energy of water species,contributes to the enhanced HOR performance under alkaline electrolyte.展开更多
This work demonstrates the outstanding performance of alloyed Au1 Pt1 nanoparticles on hydrogen oxidation reaction(HOR)in alkaline solution.Due to the weakened hydrogen binding energy caused by uniform incorporation o...This work demonstrates the outstanding performance of alloyed Au1 Pt1 nanoparticles on hydrogen oxidation reaction(HOR)in alkaline solution.Due to the weakened hydrogen binding energy caused by uniform incorporation of Au,the alloyed Au1Pt1/C nanoparticles exhibit superior HOR activity than commercial PtRu/C.On the contrary,the catalytic performance of the phase-segregated Au2Pt1/C and Au1Pt1/C bimetallic nanoparticles in HOR is significantly worse.Moreover,Au1Pt1/C shows a remarkable durability with activity dropping only 4% after 3000 CV cycles,while performance attenuation of commercial PtRu/C is high up to 15% under the same condition.Our results indicate that the alloyed Au1Pt1/C is a promising candidate to substitute commercial PtRu/C for hydrogen oxidation reaction in alkaline electrolyte.展开更多
Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire n...Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire networks(NWs) with rich interfaces and defects supported on carbon(RuO_(2)-PdO NWs/C) for alkaline hydrogen oxidation reaction(HOR) was formed by a seed induction-oriented attachment-thermal treatment method for the first time.As expected,the RuO_(2)-PdO NWs/C(72.8% Ru atomic content in metal) exhibits an excellent activity in alkaline HOR with a mass specific exchange current density(jo,m) of 1061 A gRuPd-1,which is 3.1 times of commercial Pt/C and better than most of the reported nonPt noble metal HOR electrocatalysts.Even at the high potential(~0.5 V vs.RHE) or the presence of CO(5 vol%),the RuO_(2)-PdO NWs/C still effectively catalyzes the alkaline HOR.Structure/electrochemical analysis and theoretical calculations reveal that the interfaces between RuO_(2) and PdO act as the active sites.The electronic interactions between the two species and the rich defects for the interfacial active sites weaken the adsorption of Had,also strengthen the adsorption of OHad,and accelerate the alkaline HOR process.Moreover,OHadon RuO_(2) can spillover to the interfaces,keeping the RuO_(2)-PdO NWs/C with the stable current density at higher potential and high resistance to CO poisoning.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
Two-dimensional(2D)MXene and single-atom(SA)catalysts are two frontier research fields in catalysis.2D materials with unique geometric and electronic structures can modulate the catalytic performance of supported SAs,...Two-dimensional(2D)MXene and single-atom(SA)catalysts are two frontier research fields in catalysis.2D materials with unique geometric and electronic structures can modulate the catalytic performance of supported SAs,which,in turn,affect the intrinsic activity of 2D materials.Density functional theory calculations were used to systematically explore the potential of O-terminated V2C MXene(V_(2)CO_(2))-supported transition metal(TM)SAs,including a series of 3d,4d,and 5d metals,as oxygen reduction reaction(ORR)and hydrogen oxidation reaction(HOR)catalysts.The combination of TM SAs and V_(2)CO_(2)changes their electronic structure and enriches the active sites,and consequently regulates the intermediate adsorption energy and catalytic activity for ORR and HOR.Among the investigated TM-V_(2)CO_(2)models,Sc-,Mn-,Rh-,and PtMCCh showed high ORR activity,while Sc-,Ti-,V-,Cr-,and Mn-V_(2)CO_(2)exhibited high HOR activity.Specifically,Mn-and Sc-V_(2)CO_(2)are expected to serve as highly efficient and cost-effective bifunctional catalysts for fuel cells because of their high catalytic activity and stability.This work provides theoretical guidance for the rational design of efficient ORR and HOR bifunctional catalysts.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
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
As environmental concerns and the transition to a carbon-neutral society gain importance,proton exchange membrane fuel cells(PEMFCs)using hydrogen as a fuel have attracted significant attention as eco-friendly energy ...As environmental concerns and the transition to a carbon-neutral society gain importance,proton exchange membrane fuel cells(PEMFCs)using hydrogen as a fuel have attracted significant attention as eco-friendly energy technology.Although Pt is the primary catalyst for PEMFC anodes,its high cost and limited availability pose major barriers to commercialization.To address these challenges,non-Pt catalysts,alloy catalysts,and core-shell structured catalysts have been extensively studied;nevertheless,performance degradation and structural instability remain significant issues.In this study,we design Pt-lean Pt1 Co4 alloy nanoparticles encapsulated with an ultrathin carbon shell derived from the carbon sources of the metal precursor ligands.Notably,after synthesizing the carbon-incorporated alloy nanoparticles,heat treatment under a carbon monoxide(CO)atmosphere induces selective surface segregation of Pt atoms due to their strong CO binding affinity,occurring before the carbonization temperature is reached for carbon shell formation,resulting in a Pt-enriched surface structure.The carbon shell imparts a nano-confinement effect that effectively suppresses particle growth and aggregation during heat treatment,thereby significantly enhancing electrochemical stability.Remarkably,despite a 55%reduction in Pt content,the combination of surface segregation and near-surface alloying allows the Pt-lean alloy catalyst to maintain hydrogen oxidation reaction activity comparable to a bare Pt catalyst while providing superior durability.Owing to this dual function of heat treatment,the design of the Pt-lean alloy catalyst structure offers a promising strategy for developing highly efficient and cost-effective anode catalysts for PEMFCs.展开更多
Developing efficient and stable nonplatinum catalysts for the hydrogen oxidation reaction(HOR)in acid is essential for advancing proton exchange membrane fuel cell technology.Herein,we demonstrate the enhancement of b...Developing efficient and stable nonplatinum catalysts for the hydrogen oxidation reaction(HOR)in acid is essential for advancing proton exchange membrane fuel cell technology.Herein,we demonstrate the enhancement of both the activity and stability of iridium(Ir)clusters through coordination engineering on heteroatom-doped carbon supports.Density functional theory calculations identify nitrogen doping as the optimal strategy for tuning the d-band center and hydrogen binding energy of Ir clusters.Guided by this prediction,we synthesized an Ir cluster catalyst supported on nitrogendoped carbon,which exhibits exceptional HOR activity rivaling commercial Pt/C and delivers high power densities with good operational stability in practical fuel cells.Further theoretical analysis reveals that graphitic nitrogen acts as a strong anchoring site for stabilizing Ir clusters during HOR operation.This work provides fundamental insights for designing high-performance Ir-based HOR catalysts via precise coordination environment engineering.展开更多
The anion exchange membrane fuel cell(AEMFC)enables the use of non-noble metal catalysts,greatly reducing the cost of fuel cells.Nickel-based materials are considered the most promising anode catalysts for practical a...The anion exchange membrane fuel cell(AEMFC)enables the use of non-noble metal catalysts,greatly reducing the cost of fuel cells.Nickel-based materials are considered the most promising anode catalysts for practical applications in low-cost AEMFCs,but designing Ni-based catalysts with breakthrough performance remains a major challenge due to the slow kinetics of the anodic hydrogen oxidation reaction(HOR)in alkaline media.In this review,the electrocatalytic mechanisms of the alkaline HOR and the rigorous methods for assessing the performance of Ni-based catalysts are presented as the cornerstones for designing Ni-based catalysts.Alignment with the modulated geometric and electronic properties of Ni-based catalysts is thoroughly discussed,based on the principles of mechanism and performance evaluation.An element navigation map is presented to guide the precise design of efficient Ni-based non-noble metal catalysts for the alkaline HOR,and the current challenges and future prospects are outlined to provide valuable directions for new research about the alkaline HOR on Ni.This review not only offers insights into the rational design of Ni-based electrocatalysts but also provides a blueprint for the commercialization of cost-effective AEMFCs.展开更多
Pt-based catalysts are prone to oxidation and CO poisoning during the hydrogen oxidation reaction(HOR),leading to deactivation,which has presented significant challenges for the application of proton exchange membrane...Pt-based catalysts are prone to oxidation and CO poisoning during the hydrogen oxidation reaction(HOR),leading to deactivation,which has presented significant challenges for the application of proton exchange membrane fuel cells(PEMFC).Here,we propose a dual-protection strategy with the advantages of Pt-polyoxometalates(POMs)and carbon dots(CDs)to synthesize an advanced POMs-CDs based electrocatalyst,Pt-SiW_(12)-CDs,with Pt clusters dispersed on SiW_(12)-CDs substrates.It exhibited exceptional HOR performance,achieving a mass activity of 10.36 A mgPt^(−1)at an overpotential of 50 mV,which is over 54 times greater than that of Pt/C(0.19 A mgPt^(–1)).These catalysts also display impressive stability and CO tolerance.By employing X-ray absorption fine structure(XAFS)spectra,transient photovoltage(TPV),transient potential scanning(TPS),and density functional theory(DFT)calculation,the in-depth investigation suggested the muti-roles of SiW_(12)and CDs for synergistic enhancement of Pt electrocatalyst stability and activity in HOR process.CDs act as bridges,effectively and rapidly transferring protons and electrons to SiW_(12)from Pt clusters.CDs can effectively coordinate with Pt,regulating its electronic structure while pre-occupying Pt sites,thus hindering CO adsorption on Pt.The reduced SiW_(12)efficiently transfers electrons to Pt,inhibiting the oxidation of Pt.Additionally,SiW_(12)also serves as the driving force,maintaining the rapid progression of the HOR process.The dual-protection strategy provides new ideas and directions for design of efficient and stable heterogeneous catalyst.展开更多
Sluggish kinetics of anodic hydrogen oxidation reaction(HOR)in alkaline media,which arises from the two orders of magnitude lower HOR activity in alkali than that in acid media for platinum group metals,hinders the co...Sluggish kinetics of anodic hydrogen oxidation reaction(HOR)in alkaline media,which arises from the two orders of magnitude lower HOR activity in alkali than that in acid media for platinum group metals,hinders the commercial implementation of anion exchange membrane fuel cells(AEMFCs).Consequently,the development of platinum-based catalysts combined with high efficiency and durability is urgently required.Herein,we report a facile route for the synthesis of ternary PtRuTe alloy nanofibers with Pt atomic ratio of only 11%via a simple galvanic replacement reaction.We optimize the adsorption strength of platinum and ruthenium towards hydrogen and hydroxyl species by regulating the electron donation from tellurium to platinum and ruthenium.Hence,the obtained trimetallic alloy catalyst exhibits an impressive kinetic current density of 30.6 mA cm^(−2)_(geo) at 50 mV and an exchange current density of 0.426 mA cm^(−2)_(metal),which shows 3.0-and 2.5-fold enhancement compared with the commercial Pt/C in alkaline electrolyte,respectively.Moreover,the catalyst also demonstrates excellent stability with merely 5%activity attenuation after 2000 potential cycles.This work offers new pathways to boost alkaline HOR by rationally designing multicomponent alloys.展开更多
To achieve the goals of the peak carbon dioxide emissions and carbon neutral,the development and utilization of sustainable clean energy are extremely important.Hydrogen fuel cells are an important system for converti...To achieve the goals of the peak carbon dioxide emissions and carbon neutral,the development and utilization of sustainable clean energy are extremely important.Hydrogen fuel cells are an important system for converting hydrogen energy into electrical energy.However,the slow hydrogen oxidation reaction(HOR)kinetics under alkaline conditions has limited its development.Therefore,elucidating the catalytic mechanism of HOR in acidic and alkaline media is of great significance for the construction of highly active and stable catalysts.In terms of practicality,Pt is still the primary choice for commercialization of fuel cells.On the above basis,we first introduced the hydrogen binding energy theory and bifunctional theory used to describe the HOR activity,as well as the pH dependence.After that,the rational design strategies of Pt-based HOR catalysts were systematically classified and summarized from the perspective of activity descriptors.In addition,we further emphasized the importance of theoretical simulations and in situ characterization in revealing the HOR mechanism,which is crucial for the rational design of catalysts.Moreover,the practical application of Pt-based HOR catalysts in fuel cells was also presented.In closing,the current challenges and future development directions of HOR catalysts were discussed.This review will provide a deep understanding for exploring the mechanism of highly efficient HOR catalysts and the development of fuel cells.展开更多
Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte ...Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte fuel cells(APEFCs).Herein,we report the synthesis of amorphous RuCr nanosheets with different molar ratios and their HOR performances under alkaline media.We find a volcano correlation between the Cr content in RuCr nanosheets and their alkaline HOR performance.Experimental results and density functional theory(DFT)calculation reveals that the optimized Cr content in RuCr nanosheets could lead to the optimum hydroxide binding energy(OHBE),contributes to their remarkable alkaline HOR performance with mass activity of 568.1 A·gPGM^(–1) at 50 mV,13-fold higher than that of Ru catalyst.When RuCr nanosheet is further used as the anodic electrocatalyst,a peak power density of 1.04 W·cm^(–2 )can be achieved in an APEFC.展开更多
The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic...The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic gap are indispensable and challenging.Here,the HOR behaviors of palladium phosphides and their counterpart(PdP_2/C,Pd_5P_2/C,Pd_3P/C,and Pd/C)in the whole pH region(from pH 1 to 13)are explored.Unexpectedly,there are non-monotonous relationships between their HOR kinetics and varied pHs,showing distinct inflection-point behaviors(inflection points and acid-base kinetic gaps).We find the inflection-point behaviors can be explained by the discrepant role of pH-dependent hydroxyl binding energy(OHBE)and hydrogen binding energy(HBE)induced HOR kinetics under the entire pH range.We further reveal that the strengthened OHBE is responsible for the earlier appearance of the inflection point and much narrower acid-base kinetic gap.These findings are conducive to understanding the mechanism of the pH-targeted HOR process,and provide a new strategy for rational designing advanced HOR electrocatalysts under alkaline electrolyte.展开更多
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.
基金supported by the National Key Research and Development Program of China,China(2023YFB4006202)the National Natural Science Foundation of China,China(22272206)the Natural Science Foundation of Hunan Province,China(2023JJ10061).
文摘Storing hydrogen in green methanol is a well-known and cost-effective way for long-term energy storage.However,using green methanol in fuel cell technologies requires electrocatalysts with superior resistance to poisoning induced by intermediate species.This study introduces a new class of palladium-based rare earth(RE)alloys with exceptional resistance to methanol for the oxygen reduction reaction(ORR)and outstanding resistance to carbon monoxide poisoning for the hydrogen oxidation reaction(HOR).The PdEr catalyst achieved unparalleled ORR activity amongst the Pd-based rare earth alloys and demonstrated remarkable resistance to methanol poisoning,which is two orders of magnitude higher than commercial Pt/C catalysts.Furthermore,the PdEr catalyst shows high hydrogen oxidation activity under 100 ppm CO.Comprehensive analysis demonstrates that the RE element-enriched sublayer tuning of the Pd-skin's surface strain is responsible for the enhanced ORR and HOR capabilities.This modification allows for precise control over the adsorption strength of critical intermediates while concurrently diminishing the adsorption energy of methanol and CO on the PdEr surface.
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 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Anion exchange membrane(AEM)fuel cells have gained great attention partially due to the advantage of using non-precious metal as catalysts.However,the reaction kinetics of hydrogen oxidation reaction(HOR)is two orders of magnitude slower in alkaline systems than in acid.To understand the slower kinetics of HOR in base,two major theories have been proposed,such as(1)pH dependent hydrogen binding energy as a major descriptor for HOR;and(2)bifunctional theory based on the contributions of both hydrogen and hydroxide adsorption for HOR in alkaline electrolyte.Here,we discuss the possible HOR mechanisms in alkaline electrolytes with the corresponding change in their Tafel behavior.Apart from the traditional Tafel-Volmer and Heyrovsky-Volmer HOR mechanisms,the recently proposed hydroxide adsorption step is also discussed to illustrate the difference in HOR mechanisms in acid and base.We further summarize the representative works of alkaline HOR catalyst design(e.g.,precious metals,alloy,intermetallic materials,Ni-based alloys,carbides,nitrides,etc.),and briefly describe their fundamental HOR reaction mechanism to emphasize the difference in elementary reaction steps in alkaline medium.The strategy of strengthening local interaction that facilitates both H2 desorption and Hads+OHads recombination is finally proposed for future HOR catalyst design in alkaline environment.
文摘Developing highly efficient platinum‐group‐metal‐free electrocatalysts towards hydrogen oxidation reaction(HOR)under alkaline electrolyte is critical for the development of alkaline exchange member fuel cells.Herein,we reported the synthesis of boron doped Ni electrocatalyst(B‐Ni/C)and its remarkable alkaline HOR performance,with a 10‐fold mass activity enhancement compared with that of undoped Ni catalyst.Experimental results and density functional theory calculations indicate the d‐p hybridization between the p orbital of B and the d orbital of Ni via B‐doping could lead to promoted OH adsorption and optimized hydrogen binding energy on Ni surface,which together with the reduced formation energy of water species,contributes to the enhanced HOR performance under alkaline electrolyte.
基金financially supported by the National Natural Science Foundation of China (Grants no. 21376283, 21436003 and 21576032)
文摘This work demonstrates the outstanding performance of alloyed Au1 Pt1 nanoparticles on hydrogen oxidation reaction(HOR)in alkaline solution.Due to the weakened hydrogen binding energy caused by uniform incorporation of Au,the alloyed Au1Pt1/C nanoparticles exhibit superior HOR activity than commercial PtRu/C.On the contrary,the catalytic performance of the phase-segregated Au2Pt1/C and Au1Pt1/C bimetallic nanoparticles in HOR is significantly worse.Moreover,Au1Pt1/C shows a remarkable durability with activity dropping only 4% after 3000 CV cycles,while performance attenuation of commercial PtRu/C is high up to 15% under the same condition.Our results indicate that the alloyed Au1Pt1/C is a promising candidate to substitute commercial PtRu/C for hydrogen oxidation reaction in alkaline electrolyte.
基金supported by the National Natural Science Foundation of China (22262018)Young Science and Technology Fund in Gansu Province of China (21JR7RA252)+2 种基金Natural Research Fund of Gansu Province (20JR5RA441)Lanzhou Open Competition Mechanism,Merit Based Admission Project Major Fund (2021-JB-6)National Engineering&Fund for National Nickel and Cobalt Advanced Materials Engineering Research Center(GCZX2021JSKF001)。
文摘Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire networks(NWs) with rich interfaces and defects supported on carbon(RuO_(2)-PdO NWs/C) for alkaline hydrogen oxidation reaction(HOR) was formed by a seed induction-oriented attachment-thermal treatment method for the first time.As expected,the RuO_(2)-PdO NWs/C(72.8% Ru atomic content in metal) exhibits an excellent activity in alkaline HOR with a mass specific exchange current density(jo,m) of 1061 A gRuPd-1,which is 3.1 times of commercial Pt/C and better than most of the reported nonPt noble metal HOR electrocatalysts.Even at the high potential(~0.5 V vs.RHE) or the presence of CO(5 vol%),the RuO_(2)-PdO NWs/C still effectively catalyzes the alkaline HOR.Structure/electrochemical analysis and theoretical calculations reveal that the interfaces between RuO_(2) and PdO act as the active sites.The electronic interactions between the two species and the rich defects for the interfacial active sites weaken the adsorption of Had,also strengthen the adsorption of OHad,and accelerate the alkaline HOR process.Moreover,OHadon RuO_(2) can spillover to the interfaces,keeping the RuO_(2)-PdO NWs/C with the stable current density at higher potential and high resistance to CO poisoning.
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.
文摘Two-dimensional(2D)MXene and single-atom(SA)catalysts are two frontier research fields in catalysis.2D materials with unique geometric and electronic structures can modulate the catalytic performance of supported SAs,which,in turn,affect the intrinsic activity of 2D materials.Density functional theory calculations were used to systematically explore the potential of O-terminated V2C MXene(V_(2)CO_(2))-supported transition metal(TM)SAs,including a series of 3d,4d,and 5d metals,as oxygen reduction reaction(ORR)and hydrogen oxidation reaction(HOR)catalysts.The combination of TM SAs and V_(2)CO_(2)changes their electronic structure and enriches the active sites,and consequently regulates the intermediate adsorption energy and catalytic activity for ORR and HOR.Among the investigated TM-V_(2)CO_(2)models,Sc-,Mn-,Rh-,and PtMCCh showed high ORR activity,while Sc-,Ti-,V-,Cr-,and Mn-V_(2)CO_(2)exhibited high HOR activity.Specifically,Mn-and Sc-V_(2)CO_(2)are expected to serve as highly efficient and cost-effective bifunctional catalysts for fuel cells because of their high catalytic activity and stability.This work provides theoretical guidance for the rational design of efficient ORR and HOR bifunctional catalysts.
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.
基金supported by the Technology Innovation Program(Nos.20020400,RS-2024-00423147)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)by a National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.RS-2021-NR059501).
文摘As environmental concerns and the transition to a carbon-neutral society gain importance,proton exchange membrane fuel cells(PEMFCs)using hydrogen as a fuel have attracted significant attention as eco-friendly energy technology.Although Pt is the primary catalyst for PEMFC anodes,its high cost and limited availability pose major barriers to commercialization.To address these challenges,non-Pt catalysts,alloy catalysts,and core-shell structured catalysts have been extensively studied;nevertheless,performance degradation and structural instability remain significant issues.In this study,we design Pt-lean Pt1 Co4 alloy nanoparticles encapsulated with an ultrathin carbon shell derived from the carbon sources of the metal precursor ligands.Notably,after synthesizing the carbon-incorporated alloy nanoparticles,heat treatment under a carbon monoxide(CO)atmosphere induces selective surface segregation of Pt atoms due to their strong CO binding affinity,occurring before the carbonization temperature is reached for carbon shell formation,resulting in a Pt-enriched surface structure.The carbon shell imparts a nano-confinement effect that effectively suppresses particle growth and aggregation during heat treatment,thereby significantly enhancing electrochemical stability.Remarkably,despite a 55%reduction in Pt content,the combination of surface segregation and near-surface alloying allows the Pt-lean alloy catalyst to maintain hydrogen oxidation reaction activity comparable to a bare Pt catalyst while providing superior durability.Owing to this dual function of heat treatment,the design of the Pt-lean alloy catalyst structure offers a promising strategy for developing highly efficient and cost-effective anode catalysts for PEMFCs.
基金supported by the Key R&D Program of Zhejiang(grant no.2024SSYS0081)the National Natural Science Foundation of China(grant nos.22225903,U21A20328,52222106,and 22409013)the China Postdoctoral Science Foundation(grant no.2022M720013).
文摘Developing efficient and stable nonplatinum catalysts for the hydrogen oxidation reaction(HOR)in acid is essential for advancing proton exchange membrane fuel cell technology.Herein,we demonstrate the enhancement of both the activity and stability of iridium(Ir)clusters through coordination engineering on heteroatom-doped carbon supports.Density functional theory calculations identify nitrogen doping as the optimal strategy for tuning the d-band center and hydrogen binding energy of Ir clusters.Guided by this prediction,we synthesized an Ir cluster catalyst supported on nitrogendoped carbon,which exhibits exceptional HOR activity rivaling commercial Pt/C and delivers high power densities with good operational stability in practical fuel cells.Further theoretical analysis reveals that graphitic nitrogen acts as a strong anchoring site for stabilizing Ir clusters during HOR operation.This work provides fundamental insights for designing high-performance Ir-based HOR catalysts via precise coordination environment engineering.
基金supported by the National Natural Science Foundation of China(22279036)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003).
文摘The anion exchange membrane fuel cell(AEMFC)enables the use of non-noble metal catalysts,greatly reducing the cost of fuel cells.Nickel-based materials are considered the most promising anode catalysts for practical applications in low-cost AEMFCs,but designing Ni-based catalysts with breakthrough performance remains a major challenge due to the slow kinetics of the anodic hydrogen oxidation reaction(HOR)in alkaline media.In this review,the electrocatalytic mechanisms of the alkaline HOR and the rigorous methods for assessing the performance of Ni-based catalysts are presented as the cornerstones for designing Ni-based catalysts.Alignment with the modulated geometric and electronic properties of Ni-based catalysts is thoroughly discussed,based on the principles of mechanism and performance evaluation.An element navigation map is presented to guide the precise design of efficient Ni-based non-noble metal catalysts for the alkaline HOR,and the current challenges and future prospects are outlined to provide valuable directions for new research about the alkaline HOR on Ni.This review not only offers insights into the rational design of Ni-based electrocatalysts but also provides a blueprint for the commercialization of cost-effective AEMFCs.
基金supported by the National Key R&D Program of China(2024YFA1509300)the Natural Science Foundation of Jiangsu Province(BK20220028)+4 种基金the National Natural Science Foundation of China(52272043,52271223,52472049,52472230,52202107,22171041,22471030,22379024,and 21671036)the Science and Technology Development Fund,Macao SAR(0009/2022/ITP)State Key Laboratory of Catalysis(2024SKL-A-014)Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 ProjectSuzhou Key Laboratory of Functional Nano&Soft Materials.
文摘Pt-based catalysts are prone to oxidation and CO poisoning during the hydrogen oxidation reaction(HOR),leading to deactivation,which has presented significant challenges for the application of proton exchange membrane fuel cells(PEMFC).Here,we propose a dual-protection strategy with the advantages of Pt-polyoxometalates(POMs)and carbon dots(CDs)to synthesize an advanced POMs-CDs based electrocatalyst,Pt-SiW_(12)-CDs,with Pt clusters dispersed on SiW_(12)-CDs substrates.It exhibited exceptional HOR performance,achieving a mass activity of 10.36 A mgPt^(−1)at an overpotential of 50 mV,which is over 54 times greater than that of Pt/C(0.19 A mgPt^(–1)).These catalysts also display impressive stability and CO tolerance.By employing X-ray absorption fine structure(XAFS)spectra,transient photovoltage(TPV),transient potential scanning(TPS),and density functional theory(DFT)calculation,the in-depth investigation suggested the muti-roles of SiW_(12)and CDs for synergistic enhancement of Pt electrocatalyst stability and activity in HOR process.CDs act as bridges,effectively and rapidly transferring protons and electrons to SiW_(12)from Pt clusters.CDs can effectively coordinate with Pt,regulating its electronic structure while pre-occupying Pt sites,thus hindering CO adsorption on Pt.The reduced SiW_(12)efficiently transfers electrons to Pt,inhibiting the oxidation of Pt.Additionally,SiW_(12)also serves as the driving force,maintaining the rapid progression of the HOR process.The dual-protection strategy provides new ideas and directions for design of efficient and stable heterogeneous catalyst.
基金the National Natural Science Foundation of China(21905178)Shenzhen Science and Technology Program(JCYJ20190808143007479 and JCYJ20170818144659020).
文摘Sluggish kinetics of anodic hydrogen oxidation reaction(HOR)in alkaline media,which arises from the two orders of magnitude lower HOR activity in alkali than that in acid media for platinum group metals,hinders the commercial implementation of anion exchange membrane fuel cells(AEMFCs).Consequently,the development of platinum-based catalysts combined with high efficiency and durability is urgently required.Herein,we report a facile route for the synthesis of ternary PtRuTe alloy nanofibers with Pt atomic ratio of only 11%via a simple galvanic replacement reaction.We optimize the adsorption strength of platinum and ruthenium towards hydrogen and hydroxyl species by regulating the electron donation from tellurium to platinum and ruthenium.Hence,the obtained trimetallic alloy catalyst exhibits an impressive kinetic current density of 30.6 mA cm^(−2)_(geo) at 50 mV and an exchange current density of 0.426 mA cm^(−2)_(metal),which shows 3.0-and 2.5-fold enhancement compared with the commercial Pt/C in alkaline electrolyte,respectively.Moreover,the catalyst also demonstrates excellent stability with merely 5%activity attenuation after 2000 potential cycles.This work offers new pathways to boost alkaline HOR by rationally designing multicomponent alloys.
基金support of this research by the National Natural Science Foundation of China(Nos.22179034 and 22279030)the Natural Science Foundation of Heilongjiang Province(No.ZD2023B002).
文摘To achieve the goals of the peak carbon dioxide emissions and carbon neutral,the development and utilization of sustainable clean energy are extremely important.Hydrogen fuel cells are an important system for converting hydrogen energy into electrical energy.However,the slow hydrogen oxidation reaction(HOR)kinetics under alkaline conditions has limited its development.Therefore,elucidating the catalytic mechanism of HOR in acidic and alkaline media is of great significance for the construction of highly active and stable catalysts.In terms of practicality,Pt is still the primary choice for commercialization of fuel cells.On the above basis,we first introduced the hydrogen binding energy theory and bifunctional theory used to describe the HOR activity,as well as the pH dependence.After that,the rational design strategies of Pt-based HOR catalysts were systematically classified and summarized from the perspective of activity descriptors.In addition,we further emphasized the importance of theoretical simulations and in situ characterization in revealing the HOR mechanism,which is crucial for the rational design of catalysts.Moreover,the practical application of Pt-based HOR catalysts in fuel cells was also presented.In closing,the current challenges and future development directions of HOR catalysts were discussed.This review will provide a deep understanding for exploring the mechanism of highly efficient HOR catalysts and the development of fuel cells.
基金supported bythe National Key Research and Development program of China(2021YFB4001200,2018YFB1502302)the National Natural Science Foundation of China(21972107)+1 种基金the Fundamental Reseearch Funds for the Central Universities(2042022kf1179)the Natural Science Foundation of Hubei Province(2020CFA095)。
文摘Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte fuel cells(APEFCs).Herein,we report the synthesis of amorphous RuCr nanosheets with different molar ratios and their HOR performances under alkaline media.We find a volcano correlation between the Cr content in RuCr nanosheets and their alkaline HOR performance.Experimental results and density functional theory(DFT)calculation reveals that the optimized Cr content in RuCr nanosheets could lead to the optimum hydroxide binding energy(OHBE),contributes to their remarkable alkaline HOR performance with mass activity of 568.1 A·gPGM^(–1) at 50 mV,13-fold higher than that of Ru catalyst.When RuCr nanosheet is further used as the anodic electrocatalyst,a peak power density of 1.04 W·cm^(–2 )can be achieved in an APEFC.
基金supported by the National Key Research and Development Program of China(2021YFB4001200)the National Natural Science Foundation of China(22272121,21972107)the Natural Science Foundation of Hubei Province(2020CFA095)。
文摘The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic gap are indispensable and challenging.Here,the HOR behaviors of palladium phosphides and their counterpart(PdP_2/C,Pd_5P_2/C,Pd_3P/C,and Pd/C)in the whole pH region(from pH 1 to 13)are explored.Unexpectedly,there are non-monotonous relationships between their HOR kinetics and varied pHs,showing distinct inflection-point behaviors(inflection points and acid-base kinetic gaps).We find the inflection-point behaviors can be explained by the discrepant role of pH-dependent hydroxyl binding energy(OHBE)and hydrogen binding energy(HBE)induced HOR kinetics under the entire pH range.We further reveal that the strengthened OHBE is responsible for the earlier appearance of the inflection point and much narrower acid-base kinetic gap.These findings are conducive to understanding the mechanism of the pH-targeted HOR process,and provide a new strategy for rational designing advanced HOR electrocatalysts under alkaline electrolyte.
