Formic acid holds great potential as a fuel for low-temperature proton-exchange membrane fuel cells and portable power devices because of its excellent safety profile and high energy density.However,formic acid oxidat...Formic acid holds great potential as a fuel for low-temperature proton-exchange membrane fuel cells and portable power devices because of its excellent safety profile and high energy density.However,formic acid oxidation reactions(FAOR)face challenges such as low catalytic activity,poor stability,and catalyst poisoning.Atomically dispersed catalysts(ADCs)address these issues by providing a direct oxidation pathway,inhibiting catalyst poisoning,and offering well-defined catalytic sites with ultimate atomic efficiency.This review provides a comprehensive summary of recent breakthroughs in ADCs for FAOR.First,we discuss the structural design and mechanism validation methods of ADCs using enhanced sensitivity,in situ/operando,and high-resolution techniques.Next,we summarize bottom-up optimization strategies for ADCs,guided by the structure-activity relationship and reaction mechanisms at the atomic and electronic levels.Finally,we offer insights into device design and scale-up efforts for FAOR applications and provide an overlook from fundamental catalyst design to practical applications.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
The development of an efficient catalyst for formic acid electrocatalytic oxidation reaction(FAEOR)is of great significance to accelerate the commercial application of direct formic acid fuel cells(DFAFC).Herein,palla...The development of an efficient catalyst for formic acid electrocatalytic oxidation reaction(FAEOR)is of great significance to accelerate the commercial application of direct formic acid fuel cells(DFAFC).Herein,palladium phosphide(PdxPy)porous nanotubes(PNTs)with different phosphide content(i.e.,Pd3P and Pd5P2)are prepared by combining the self-template reduction method of dimethylglyoxime-Pd(II)complex nanorods and succedent phosphating treatment.During the reduction process,the self-removal of the template and the continual inside-outside Ostwald ripening phenomenon are responsible for the generation of the one-dimensional hollow and porous architecture.On the basis of the unique synthetic procedure and structural advantages,Pd3P PNTs with optimized phos phide content show outstanding electroactivity and stability for FAEOR.Im portantly,the strong electronic effect between Pd and P promotes the direct pathway of FAEOR and inhibits the occurrence of the formic acid decomposition reaction,which effectively enhances the FAEOR electroactivity of Pd3P PNTs.In view of the facial synthesis,excellent electroactivity,high stability,and unordinary selectivity,Pd3P PNTs have the potential to be an efficient anode electrocatalyst for DFAFC.展开更多
Anti-CO poisoning ability is significant in formic acid oxidation in the fuel cell technique.Herein,Pd Ni alloy supported on N-doped graphene aerogel(Pd Ni/GA-N)was found to have catalytic ability toward formic acid e...Anti-CO poisoning ability is significant in formic acid oxidation in the fuel cell technique.Herein,Pd Ni alloy supported on N-doped graphene aerogel(Pd Ni/GA-N)was found to have catalytic ability toward formic acid electrooxidation over a wide potential range because of the improved anti-CO poisoning ability.This catalyst was fabricated by simple freeze-drying of mixture solution of graphene aerogel,polyvinylpyrrolidone,Pd^(2+)and Ni^(2+)and the subsequent thermal annealing reduction approach in the N2/H2 atmosphere.Pd-Ni alloy particles anchored over the folding N-doped graphene surface with a porous hierarchical architecture structure in the 3 D directions.It showed the catalytic performance of its maximum mass activity of 836 m A mg^(-1)in a broad potential range(0.2-0.6 V)for formic acid oxidation.The CO stripping experiment demonstrated its largely improved anti-CO poisoning ability with the peak potential of 0.67 V,approximately 60 and 40 m V less compared to those of Pd/GA-N and Pd/C samples.The high anti-CO poisoning ability and strong electronic effect resulting from the interaction between the3 D GA-N support and the Pd-Ni alloy makes it a promising catalyst for application in direct formic acid fuel cells.展开更多
Both structure and interface engineering are highly effective strategies for enhancing the catalytic activity and selectivity of precious metal nanostructures.In this work,we develop a facile pyrolysis strategy to syn...Both structure and interface engineering are highly effective strategies for enhancing the catalytic activity and selectivity of precious metal nanostructures.In this work,we develop a facile pyrolysis strategy to synthesize the high-quality holey platinum nanotubes(Pt-H-NTs)using nanorods-like Pt^(Ⅱ)-phenanthroline(PT)coordination compound as self-template and self-reduction precursor.Then,an up-bottom strategy is used to further synthesize polyallylamine(PA)modified Pt-H-NTs(Pt-HNTs@PA).PA modification sharply promotes the catalytic activity of Pt-H-NTs for the formic acid electrooxidation reaction(FAEOR)by the direct reaction pathway.Meanwhile,PA modification also elevates the catalytic activity of Pt-H-NTs for the hydrogen evolution reaction(HER)by the proton enrichment at electrolyte/electrode interface.Benefiting from the high catalytic activity of Pt-H-NTs@PA for both FAEOR and HER,a two-electrode FAEOR boosted water electrolysis system is fabricated by using Pt-H-NTs@PA as bifunctio nal electrocatalysts.Such FAEOR boosted water electrolysis system only requires the operational voltage of 0.47 V to achieve the high-purity hydrogen production,showing an energy-saving hydrogen production strategy compared to traditional water electrolysis system.展开更多
Inefficient electrocatalysts and high-power consumption are two thorny problems for electrochemical hydrogen(H2)production from acidic water electrolysis.Herein we report the one-pot precise synthesis of ultrafine Au ...Inefficient electrocatalysts and high-power consumption are two thorny problems for electrochemical hydrogen(H2)production from acidic water electrolysis.Herein we report the one-pot precise synthesis of ultrafine Au core-Pt Au alloy shell nanowires(Au@PtxAu UFNWs).Among them,Au@Pt_(0.077) Au UFNWs exhibit the best performance for formic acid oxidation reaction(FAOR)and hydrogen evolution reaction(HER),which only require applied potentials of 0.29 V and-22.6 m V to achieve a current density of 10 m A cm^(-2),respectively.The corresponding formic acid electrolyzer realizes the electrochemical H2 production at a voltage of only 0.51 V with 10 m A cm^(-2) current density.Density functional theory(DFT)calculations reveal that the Au-riched Pt Au alloy structure can facilitates the direct oxidation pathway of FAOR and consequently elevates the FAOR activity of Au@Pt_(0.077) Au UFNWs.This work provides meaningful insights into the electrochemical H_(2) production from both the construction of advanced bifunctional electrocatalysts and the replacement of OER.展开更多
Light-metalloid-atom-doped Pd interstitial nanoalloy is promising candidate for electrocatalysis because of the favorable electronic effect.Herein,an innovative method was developed to synthesize C-doped Pd interstiti...Light-metalloid-atom-doped Pd interstitial nanoalloy is promising candidate for electrocatalysis because of the favorable electronic effect.Herein,an innovative method was developed to synthesize C-doped Pd interstitial nanoalloy using palladium acetate both as metal precursor and C dopant.Elaborate characterizations demonstrated that C atoms were successfully doped into the Pd lattice via self-catalytic decomposition of acetate ions.The as-synthesized C-doped Pd catalysts showed excellent activity and durable stability for formic acid electrooxidation.The mass activity and specific activity at 0.6 V of C-doped Pd were approximately 2.59 A/mg and 3.50 mA cm^(-2),i.e.,2.4 and 2.6 times of Pd,respectively.DFT calculations revealed that interstitial doping with C atoms induced differentiation of Pd sites.The strong noncovalent interaction between the Pd sites and the key intermediates endowed Pd with high-selectivity to direct routes and enhanced CO tolerance.This work presents a sites-differentiation strategy for metallic catalysts to improve the electrocatalysis.展开更多
Crystallographic defects in noble metal nanocrystals are recognized as highly active catalytic sites,significantly enhancing activities in many important reactions.Despite their importance,synthesizing noble metal nan...Crystallographic defects in noble metal nanocrystals are recognized as highly active catalytic sites,significantly enhancing activities in many important reactions.Despite their importance,synthesizing noble metal nanocrystals with a high density of defects poses a considerable synthetic challenge.Here,we present a novel lattice mismatch-induced formation mechanism to create high-density defects in noble metal nanocrystals.This approach takes advantage of lattice mismatch to enable nonepitaxial nucleation and growth of a noble metal on a foreign metal substrate,forming abundant noble metal crystallites with random lattice orientations not dictated by the substrate lattice.As these crystallites grow extensively,they merge,forming numerous grain boundaries and yielding defect-rich noble metal nanocrystals.Defect-rich alloy nanocrystals can also be synthesized through a subsequent vacancy-diffusion alloying process.We take defective PdCu alloy nanocages as an example and demonstrate the effectiveness of crystallographic defects in enhancing catalytic performance of noble metal nanocrystals.The nanocages exhibit superior activity in the electrocatalytic formic acid oxidation reaction,which is 1.6 times greater than their defect-free counterparts.Our strategy offers a new avenue for creating defect-rich noble metal nanocrystals as highly efficient catalysts for a wide array of catalytic applications.展开更多
Exploring a new strategy for the removal of adsorbed CO (CO^(*)) on a Pt surface at a low potential is the key to achieving enhanced catalysis for the formic acid oxidation reaction (FAOR);however, the development of ...Exploring a new strategy for the removal of adsorbed CO (CO^(*)) on a Pt surface at a low potential is the key to achieving enhanced catalysis for the formic acid oxidation reaction (FAOR);however, the development of such a strategy remains a significant challenge. Herein, we report a class of Au/PtCo heterojunction nanowires (HNWs) as efficient electrocatalysts for accelerating the FAOR. This heterojunction structure and the induced Co alloying effects can facilitate formic acid adsorption/activation on Pt with high CO tolerance, generating the FAOR pathway from dehydration to dehydrogenation. The optimized Au_(23)/Pt_(63)Co_(14) HNWs showed the highest specific and mass activities of 11.7 mA cm^(−2)Pt and 6.42 A mg^(−1)Pt reported to date, respectively, which are considerably higher than those of commercial Pt/C. DFT calculations confirmed that the electron-rich Au segment enhances the electronic activity of the PtCo NWs, which not only allows the construction of a highly efficient electron transfer channel for the FAOR but also suppresses CO formation.展开更多
Recently, the surface chemical functionalization and morphology control of precious metal nanostructures have been recognized as two efficient strategies for improving their electroactivity and/or selectivity. In this...Recently, the surface chemical functionalization and morphology control of precious metal nanostructures have been recognized as two efficient strategies for improving their electroactivity and/or selectivity. In this work, 1, 10-phenanthroline monohydrate(PM) functionalized Pt nanodendrites(Pt-NDs) on carbon cloth(CC)(denoted as PM@Pt-NDs/CC) and polyethylenimine(PEI) functionalized Pt-NDs on CC(denoted as PEI@Pt-NDs/CC) are successfully achieved by immersing Pt-NDs/CC into PM and PEI aqueous solutions, respectively. PEI functionalization of Pt-NDs/CC improves its electroactivity for hydrogen evolution reaction(HER) due to local proton enrichment whereas PM functionalization of Pt-NDs/CC improves its electroactivity for formic acid oxidation reaction(FAOR) by facilitating dehydrogenation pathway. With such high activity, a two-electrode electrolyzer is assembled using PM@Pt-NDs/CC as the anodic electrocatalyst and PEI@Pt-NDs/CC as the cathodic electrocatalyst for electrochemical reforming of formic acid, which only requires 0.45 V voltage to achieve the current density of 10 mA cm^(-1) for highpurity hydrogen production, much lower than conventional water electrolysis(1.59 V). The work presents an example of interfacial engineering enhancing electrocatalytic activity and indicates that electrochemical reforming of formic acid is an energy-saving electrochemical method for high-purity hydrogen production.展开更多
The formation of porosity within nanoparticles via dealloying is notably constrained by the dimensions of the precursor particles,a limitation stemming from the surface kinetic processes occurring during dealloying.In...The formation of porosity within nanoparticles via dealloying is notably constrained by the dimensions of the precursor particles,a limitation stemming from the surface kinetic processes occurring during dealloying.In this study,we present a straightforward methodology,specifically tailored for fabricating diminutive nanoporous alloy nanoparticles,originating from their small-sized precursor counterparts.We initiated our research with precursor PtNi alloy nanoparticles,which possess an average diameter of 9 nm.By incorporating an extrinsic metal,Ir,known for its slower surface diffusion on the nanoparticle surface,we successfully modulated the surface migration velocity of Pt during the dealloying process of the PtNi alloy nanoparticles.This precise manipulation led to the formation of an abundantly complex nanoporous structure on diminutive PtNi nanoparticles.Owing to their enhanced high surface area-to-volume ratio and the synergistic alloy effect,electrochemical tests revealed that the Ir-coated diminutive nanoporous PtNi nanoparticles exhibit superior electrocatalytic activities towards oxygen reduction and formic acid oxidation reactions.Furthermore,the presence of Ir on the surface effectively suppresses the surface diffusion rate of Pt,thereby significantly inhibiting the coarsening evolution of the porous metallic structure.This intervention ensures the long-term preservation of both structural integrity and catalytic stability.展开更多
Electrochemical energy storage and conversion toward sustainable carbon neutrality cycle is of great interest in today's society.In this perspective,we highlight the interconversion between carbon dioxide and form...Electrochemical energy storage and conversion toward sustainable carbon neutrality cycle is of great interest in today's society.In this perspective,we highlight the interconversion between carbon dioxide and formic acid by means of electrocatalytic CO_(2)reduction reaction(CO_(2)RR)and formic acid oxidation reaction(FAOR)as an effective way to achieve that goal.In line with the distinctive catalytic nature of Pd to reversibly drive both FAOR and CO_(2)RR,we first illustrate the intimate mechanistic relation between these two reversed reactions over Pd surfaces.Next,recent advances in developing Pd-based bifunctional catalysts and relevant optimization strategies are briefly summarized,including geometric structure engineering with preferential facet exposure,construction of crystallographic ordering intermetallic,electronic structure manipulation through metal or metalloid doping to fine tune the binding strength for active and poisoning intermediates.At the end,our viewpoints on the design principles at both microscopic and macroscopic scales are offered toward an efficient CO_(2)and HCOOH interconversion loop.展开更多
基金supported by The National Key R&D Program of China(2022YFA1505700)National Natural Science Foundation of China(22475214 and 22205232)+3 种基金Talent Plan of Shanghai Branch,Chinese Academy of Sciences(CASSHB-QNPD-2023-020)Natural Science Foundation of Fujian Province(2023J06044)the SelfDeployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(CXZX-2022-JQ06 and CXZX-2022-GH03)the Postdoctoral Fellowship Program of the China Postdoctoral Science Foundation(CPSF,GZC20241727)。
文摘Formic acid holds great potential as a fuel for low-temperature proton-exchange membrane fuel cells and portable power devices because of its excellent safety profile and high energy density.However,formic acid oxidation reactions(FAOR)face challenges such as low catalytic activity,poor stability,and catalyst poisoning.Atomically dispersed catalysts(ADCs)address these issues by providing a direct oxidation pathway,inhibiting catalyst poisoning,and offering well-defined catalytic sites with ultimate atomic efficiency.This review provides a comprehensive summary of recent breakthroughs in ADCs for FAOR.First,we discuss the structural design and mechanism validation methods of ADCs using enhanced sensitivity,in situ/operando,and high-resolution techniques.Next,we summarize bottom-up optimization strategies for ADCs,guided by the structure-activity relationship and reaction mechanisms at the atomic and electronic levels.Finally,we offer insights into device design and scale-up efforts for FAOR applications and provide an overlook from fundamental catalyst design to practical applications.
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 Natural Science Foundation of China(21875133 and 51873100)Natural Science Foundation of Shaanxi Province(2020JZ-23)+2 种基金the National Training Program of Innovation and Entrepreneurship for Undergraduates(S202010718130)Fundamental Research Funds for the Central Universities(GK202101005,GK202103062,and 2021CBLZ004)the 111 Project(B14041).
文摘The development of an efficient catalyst for formic acid electrocatalytic oxidation reaction(FAEOR)is of great significance to accelerate the commercial application of direct formic acid fuel cells(DFAFC).Herein,palladium phosphide(PdxPy)porous nanotubes(PNTs)with different phosphide content(i.e.,Pd3P and Pd5P2)are prepared by combining the self-template reduction method of dimethylglyoxime-Pd(II)complex nanorods and succedent phosphating treatment.During the reduction process,the self-removal of the template and the continual inside-outside Ostwald ripening phenomenon are responsible for the generation of the one-dimensional hollow and porous architecture.On the basis of the unique synthetic procedure and structural advantages,Pd3P PNTs with optimized phos phide content show outstanding electroactivity and stability for FAEOR.Im portantly,the strong electronic effect between Pd and P promotes the direct pathway of FAEOR and inhibits the occurrence of the formic acid decomposition reaction,which effectively enhances the FAEOR electroactivity of Pd3P PNTs.In view of the facial synthesis,excellent electroactivity,high stability,and unordinary selectivity,Pd3P PNTs have the potential to be an efficient anode electrocatalyst for DFAFC.
基金supported by the National Natural Science Foundation of China(21972124,21603041)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institution+1 种基金the Double Tops Joint Fund of the Yunnan Science and Technology Bureau and Yunnan University(2019FY003025)the Research Foundation of Department of Education of Yunnan Province(2020Y0018)。
文摘Anti-CO poisoning ability is significant in formic acid oxidation in the fuel cell technique.Herein,Pd Ni alloy supported on N-doped graphene aerogel(Pd Ni/GA-N)was found to have catalytic ability toward formic acid electrooxidation over a wide potential range because of the improved anti-CO poisoning ability.This catalyst was fabricated by simple freeze-drying of mixture solution of graphene aerogel,polyvinylpyrrolidone,Pd^(2+)and Ni^(2+)and the subsequent thermal annealing reduction approach in the N2/H2 atmosphere.Pd-Ni alloy particles anchored over the folding N-doped graphene surface with a porous hierarchical architecture structure in the 3 D directions.It showed the catalytic performance of its maximum mass activity of 836 m A mg^(-1)in a broad potential range(0.2-0.6 V)for formic acid oxidation.The CO stripping experiment demonstrated its largely improved anti-CO poisoning ability with the peak potential of 0.67 V,approximately 60 and 40 m V less compared to those of Pd/GA-N and Pd/C samples.The high anti-CO poisoning ability and strong electronic effect resulting from the interaction between the3 D GA-N support and the Pd-Ni alloy makes it a promising catalyst for application in direct formic acid fuel cells.
基金sponsored by the National Natural Science Foundation of China(22272103)the Natural Science Foundation of Shaanxi Province(2020JZ-23,2019KJXX-021,and 2020JM269)+7 种基金the Key Research and Development Program of Shaanxi(2020SF-355)the Science and Technology Innovation Team of Shaanxi Province(2022TD-35)the University Engineering Research Center of Crystal Growth and Applications of Guangdong Province(2020GCZX005)the Special Innovative Projects of Guangdong Province(2020KTSCX125)the Shenzhen Stable Supporting Program(SZWD2021015)the Fundamental Research Funds for the Central Universities(GK202202001)the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials at Guangxi University(2021GXYSOF02)the 111 Project(B14041)。
文摘Both structure and interface engineering are highly effective strategies for enhancing the catalytic activity and selectivity of precious metal nanostructures.In this work,we develop a facile pyrolysis strategy to synthesize the high-quality holey platinum nanotubes(Pt-H-NTs)using nanorods-like Pt^(Ⅱ)-phenanthroline(PT)coordination compound as self-template and self-reduction precursor.Then,an up-bottom strategy is used to further synthesize polyallylamine(PA)modified Pt-H-NTs(Pt-HNTs@PA).PA modification sharply promotes the catalytic activity of Pt-H-NTs for the formic acid electrooxidation reaction(FAEOR)by the direct reaction pathway.Meanwhile,PA modification also elevates the catalytic activity of Pt-H-NTs for the hydrogen evolution reaction(HER)by the proton enrichment at electrolyte/electrode interface.Benefiting from the high catalytic activity of Pt-H-NTs@PA for both FAEOR and HER,a two-electrode FAEOR boosted water electrolysis system is fabricated by using Pt-H-NTs@PA as bifunctio nal electrocatalysts.Such FAEOR boosted water electrolysis system only requires the operational voltage of 0.47 V to achieve the high-purity hydrogen production,showing an energy-saving hydrogen production strategy compared to traditional water electrolysis system.
基金supported by the Natural Science Foundation of Shaanxi Province(2020JZ-23)the Fundamental Research Funds for the Central Universities(GK201901002,GK202101005,2020CSLZ012 and 2019TS007)+4 种基金the Innovation Team Project for Graduate Student at Shaanxi Normal University(TD2020048Y)the Key Research and Development Program of Shaanxi(Program No.2020SF-355)the National Training Program of Innovation and Entrepreneurship for Undergraduates(S202010718130)the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials at Guangxi University(2021GXYSOF02)the 111 Project(B14041)。
文摘Inefficient electrocatalysts and high-power consumption are two thorny problems for electrochemical hydrogen(H2)production from acidic water electrolysis.Herein we report the one-pot precise synthesis of ultrafine Au core-Pt Au alloy shell nanowires(Au@PtxAu UFNWs).Among them,Au@Pt_(0.077) Au UFNWs exhibit the best performance for formic acid oxidation reaction(FAOR)and hydrogen evolution reaction(HER),which only require applied potentials of 0.29 V and-22.6 m V to achieve a current density of 10 m A cm^(-2),respectively.The corresponding formic acid electrolyzer realizes the electrochemical H2 production at a voltage of only 0.51 V with 10 m A cm^(-2) current density.Density functional theory(DFT)calculations reveal that the Au-riched Pt Au alloy structure can facilitates the direct oxidation pathway of FAOR and consequently elevates the FAOR activity of Au@Pt_(0.077) Au UFNWs.This work provides meaningful insights into the electrochemical H_(2) production from both the construction of advanced bifunctional electrocatalysts and the replacement of OER.
基金the financial support from the National Natural Science Foundation of China(51904191)the Overseas High-level Talents Foundation of Shenzhen。
文摘Light-metalloid-atom-doped Pd interstitial nanoalloy is promising candidate for electrocatalysis because of the favorable electronic effect.Herein,an innovative method was developed to synthesize C-doped Pd interstitial nanoalloy using palladium acetate both as metal precursor and C dopant.Elaborate characterizations demonstrated that C atoms were successfully doped into the Pd lattice via self-catalytic decomposition of acetate ions.The as-synthesized C-doped Pd catalysts showed excellent activity and durable stability for formic acid electrooxidation.The mass activity and specific activity at 0.6 V of C-doped Pd were approximately 2.59 A/mg and 3.50 mA cm^(-2),i.e.,2.4 and 2.6 times of Pd,respectively.DFT calculations revealed that interstitial doping with C atoms induced differentiation of Pd sites.The strong noncovalent interaction between the Pd sites and the key intermediates endowed Pd with high-selectivity to direct routes and enhanced CO tolerance.This work presents a sites-differentiation strategy for metallic catalysts to improve the electrocatalysis.
基金support of the National Natural Science Foundation of China(22371222)the Science Fund for Distinguished Young Scholars of Shaanxi Province(2024JC-JCQN-14)+4 种基金the Key Research and Development Projects of Shaanxi Province(2021GXLHZ-022)the Fundamental Research Funds for Central Universities.Z.L.acknowledges the support from the China Postdoctoral Science Foundation(2023TQ0263)the National Postdoctoral Research Program of China(GZC20232091)the Postdoctoral Research Project of Shaanxi Province(2023BSHYDZZ49)the Fundamental Research Funds for the Central Universities(XZY012023026).
文摘Crystallographic defects in noble metal nanocrystals are recognized as highly active catalytic sites,significantly enhancing activities in many important reactions.Despite their importance,synthesizing noble metal nanocrystals with a high density of defects poses a considerable synthetic challenge.Here,we present a novel lattice mismatch-induced formation mechanism to create high-density defects in noble metal nanocrystals.This approach takes advantage of lattice mismatch to enable nonepitaxial nucleation and growth of a noble metal on a foreign metal substrate,forming abundant noble metal crystallites with random lattice orientations not dictated by the substrate lattice.As these crystallites grow extensively,they merge,forming numerous grain boundaries and yielding defect-rich noble metal nanocrystals.Defect-rich alloy nanocrystals can also be synthesized through a subsequent vacancy-diffusion alloying process.We take defective PdCu alloy nanocages as an example and demonstrate the effectiveness of crystallographic defects in enhancing catalytic performance of noble metal nanocrystals.The nanocages exhibit superior activity in the electrocatalytic formic acid oxidation reaction,which is 1.6 times greater than their defect-free counterparts.Our strategy offers a new avenue for creating defect-rich noble metal nanocrystals as highly efficient catalysts for a wide array of catalytic applications.
基金The authors are grateful for the financial support of this work from the National Science Fund for Distinguished Young Scholars(No.52025133)Tencent Foundation through the XPLORER PRIZE,the Beijing Natural Science Foundation(JQ18005)Young Thousand Talented Program,and Postdoctoral Science Foundation of China.(2020M680200).
文摘Exploring a new strategy for the removal of adsorbed CO (CO^(*)) on a Pt surface at a low potential is the key to achieving enhanced catalysis for the formic acid oxidation reaction (FAOR);however, the development of such a strategy remains a significant challenge. Herein, we report a class of Au/PtCo heterojunction nanowires (HNWs) as efficient electrocatalysts for accelerating the FAOR. This heterojunction structure and the induced Co alloying effects can facilitate formic acid adsorption/activation on Pt with high CO tolerance, generating the FAOR pathway from dehydration to dehydrogenation. The optimized Au_(23)/Pt_(63)Co_(14) HNWs showed the highest specific and mass activities of 11.7 mA cm^(−2)Pt and 6.42 A mg^(−1)Pt reported to date, respectively, which are considerably higher than those of commercial Pt/C. DFT calculations confirmed that the electron-rich Au segment enhances the electronic activity of the PtCo NWs, which not only allows the construction of a highly efficient electron transfer channel for the FAOR but also suppresses CO formation.
基金sponsored by Natural Science Foundation of Shaanxi Province (2020JZ-23)the Fundamental Research Funds for the Central Universities (GK201901002, GK201701007 and GK201902014)the 111 Project (B14041)。
文摘Recently, the surface chemical functionalization and morphology control of precious metal nanostructures have been recognized as two efficient strategies for improving their electroactivity and/or selectivity. In this work, 1, 10-phenanthroline monohydrate(PM) functionalized Pt nanodendrites(Pt-NDs) on carbon cloth(CC)(denoted as PM@Pt-NDs/CC) and polyethylenimine(PEI) functionalized Pt-NDs on CC(denoted as PEI@Pt-NDs/CC) are successfully achieved by immersing Pt-NDs/CC into PM and PEI aqueous solutions, respectively. PEI functionalization of Pt-NDs/CC improves its electroactivity for hydrogen evolution reaction(HER) due to local proton enrichment whereas PM functionalization of Pt-NDs/CC improves its electroactivity for formic acid oxidation reaction(FAOR) by facilitating dehydrogenation pathway. With such high activity, a two-electrode electrolyzer is assembled using PM@Pt-NDs/CC as the anodic electrocatalyst and PEI@Pt-NDs/CC as the cathodic electrocatalyst for electrochemical reforming of formic acid, which only requires 0.45 V voltage to achieve the current density of 10 mA cm^(-1) for highpurity hydrogen production, much lower than conventional water electrolysis(1.59 V). The work presents an example of interfacial engineering enhancing electrocatalytic activity and indicates that electrochemical reforming of formic acid is an energy-saving electrochemical method for high-purity hydrogen production.
基金financially supported by the National Natural Science Foundation of China(Nos.22202124 and UA22A20429)Shanxi Scholarship Council of China(Nos.2023-008 and 2023-009)+5 种基金Shanxi Outstanding Project Selection and Support Program for Overseas Scientific and Technological Activities(No.20230002)Science and Technology Innovation Teams of Shanxi Province(No.202304051001023)the Key Research and Development Program of Shanxi Province(No.202302060301009)Qingdao New Energy Shandong Laboratory Open Project(QNESL OP)Shandong Provincial Natural Science Foundation(Nos.ZR2024QB175 and ZR2023LFG005)Fundamental Research Funds for the Central Universities(No.25CX07002A).
文摘The formation of porosity within nanoparticles via dealloying is notably constrained by the dimensions of the precursor particles,a limitation stemming from the surface kinetic processes occurring during dealloying.In this study,we present a straightforward methodology,specifically tailored for fabricating diminutive nanoporous alloy nanoparticles,originating from their small-sized precursor counterparts.We initiated our research with precursor PtNi alloy nanoparticles,which possess an average diameter of 9 nm.By incorporating an extrinsic metal,Ir,known for its slower surface diffusion on the nanoparticle surface,we successfully modulated the surface migration velocity of Pt during the dealloying process of the PtNi alloy nanoparticles.This precise manipulation led to the formation of an abundantly complex nanoporous structure on diminutive PtNi nanoparticles.Owing to their enhanced high surface area-to-volume ratio and the synergistic alloy effect,electrochemical tests revealed that the Ir-coated diminutive nanoporous PtNi nanoparticles exhibit superior electrocatalytic activities towards oxygen reduction and formic acid oxidation reactions.Furthermore,the presence of Ir on the surface effectively suppresses the surface diffusion rate of Pt,thereby significantly inhibiting the coarsening evolution of the porous metallic structure.This intervention ensures the long-term preservation of both structural integrity and catalytic stability.
基金supported by the National Natural Science Foundation of China(NSFC,21733004,22002088)the INTERNATIONAL COOPERATION Program of Shanghai Science and Technology Committee(STCSM,17520711200)+1 种基金the Shanghai Sailing Program(20YF1420500)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2020MS007).
文摘Electrochemical energy storage and conversion toward sustainable carbon neutrality cycle is of great interest in today's society.In this perspective,we highlight the interconversion between carbon dioxide and formic acid by means of electrocatalytic CO_(2)reduction reaction(CO_(2)RR)and formic acid oxidation reaction(FAOR)as an effective way to achieve that goal.In line with the distinctive catalytic nature of Pd to reversibly drive both FAOR and CO_(2)RR,we first illustrate the intimate mechanistic relation between these two reversed reactions over Pd surfaces.Next,recent advances in developing Pd-based bifunctional catalysts and relevant optimization strategies are briefly summarized,including geometric structure engineering with preferential facet exposure,construction of crystallographic ordering intermetallic,electronic structure manipulation through metal or metalloid doping to fine tune the binding strength for active and poisoning intermediates.At the end,our viewpoints on the design principles at both microscopic and macroscopic scales are offered toward an efficient CO_(2)and HCOOH interconversion loop.
