The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),whi...The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),which relies on the rational regulation of intermediates’binding strength.Herein,we reported a simple strategy to manipulate the adsorption energy of OH^(∗)on electrocatalyst surface via engineering Ni/NbO_(x) heterostructures with manageable oxygen vacancy(Ov).Theoretical calculations confirm that the electronic effect between Ni and NbO_(x) could weaken the hydrogen adsorption on Ni,and the interfacial oxygen vacancy tailor hydroxide binding energy(OHBE).The optimized HBE and OHBE contribute to reduce formation energy of water during the alkaline HOR process.Furthermore,in situ Raman spectroscopy monitor the dynamic process that OH^(∗)adsorbed on oxygen vacancy and react with adjacent H^(∗)adsorbed Ni,confirming the vital role of OH^(∗)for alkaline HOR process.As a result,the optimal Ni/NbO_(x) exhibits a remarkable intrinsic activity with a specific activity of 0.036mA/cm^(2),which is 4-fold than that of pristine Ni counterpart and surpasses most non-precious electrocatalysts ever reported.展开更多
The employment of single atom catalysts(SACs)remarkably increases atomic utilization and catalytic efficiency in various electrochemical processes,especially when coupled with metal clusters/nanoparticles.However,the ...The employment of single atom catalysts(SACs)remarkably increases atomic utilization and catalytic efficiency in various electrochemical processes,especially when coupled with metal clusters/nanoparticles.However,the synergistic effects mainly focus on the energetics of key intermediates during the electrocatalysis,while the properties of electrode surface and electric-double-layer(EDL)structure are largely overlooked.Herein,we report the synthesis of Ru nanoparticles integrated with neighboring Ru single atoms on nitrogen doped carbon(Ru1,n/NC)as efficient catalysts toward hydrogen oxidation reaction(HOR)under alkaline electrolytes.Electrochemical data,in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy,and density functional theory calculations reveal that the positively charged Ru single atoms could lead to the dynamically regulated proportion of strongly hydrogen-bonded interfacial water structure with O-down conformation and optimized connectivity of the hydrogen-bond network in the EDL region,which contribute to the accelerated diffusion of hydroxide ions to the electrified interfaces.Consequently,the obtained Ru1,n/NC catalyst displays remarkable HOR performance with the mass activity of 1.15 mAμgPGM^(-1) under alkaline electrolyte.This work demonstrates the promise of single atoms for interfacial water environment adjustment and mass transfer process modulation,providing new insights into rational design of highly-effective SAC-based electrocatalysts.展开更多
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
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
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
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
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
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
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
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
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
Electrochemically induced surface reconstruction offers a novel approach for in situ modulation of the surface structure of nanomaterials.However,comprehensive studies on the surface reconstruction behavior of nanomat...Electrochemically induced surface reconstruction offers a novel approach for in situ modulation of the surface structure of nanomaterials.However,comprehensive studies on the surface reconstruction behavior of nanomaterials under diverse electrochemical operations remain limited.Here,exemplified by three electrochemical operations,including cyclic voltammetry(CV),squarewave potential(SWP)and chronoamperometry(CA),we reveal the structural evolution behavior and the corresponding electrocatalytic activity of bimetallic telluride hollow nanorods(Ir_(1-x)Ru_(x)0Te_(2)HNRs).It was found that the surface Te atoms in Ir_(1-x)Ru_(x)0Te_(2)HNRs undergo preferential leaching during the CV and SWP processes,ultimately leading to the formation of a metal alloy shell.In contrast,during the CA process,the surface reconstruction induced by Te leaching was suppressed by the adsorption of anions on the electrode surface.Electrocatalytic tests show that the CV activated Ir_(0.75)Ru_(0.25)Te_(2)HNRs exhibit excellent activity for the hydrogen oxidation reaction in 0.1 M KOH,with a mass activity of 686 Ag^(-1)at an overpotential of50 mV,which is 2.9 times higher than that of commercialPt/C catalyst.Density functional theory(DFT)computation reveals that the incorporation of Ru optimizes the hydroxyl binding energy of IrRu alloy,thus resulting in the reduced reaction energy barrier of hydrogen oxidation reaction.This work provides a new insight into the design of efficient catalysts through electrochemical surface engineering.展开更多
Interface engineering is a prospective method for improving electrochemical performance,while efficient interfacial tuning is still difficult.Here,a series of WO_(3)-Ir catalysts with tuned interfaces were obtained fr...Interface engineering is a prospective method for improving electrochemical performance,while efficient interfacial tuning is still difficult.Here,a series of WO_(3)-Ir catalysts with tuned interfaces were obtained from WO_(3)support with different surface states.The prepared WO_(3)-O-Ir catalyst with higher interfacial oxygen content shows excellent hydrogen oxidation reaction activity with a mass activity of 54.04 A gIr^(-1)for hydrogen oxidation reaction,which is superior to WO_(3)-W-Ir with higher tungsten content and even commercial Pt/C catalysts.Theoretical calculation and X-ray photoelectron spectroscopy valence band spectrum analyses verify that the position of the d-band center is directly proportional to the interfacial oxygen content.This modulates the electronic structure of the active phase,increasing the binding energy for OH species and enhancing their adsorption capacity,which boost the performance for hydrogen oxidation reaction.展开更多
Active and poisoning-resistant Ru-based electrocatalysts for the hydrogen oxidation reaction(HOR)are designed and fabricated by integrating Cu/Ru dual single atoms and alloy CuRu nanoparticles(N-(CuRu)_(NP+SA)@NC)thro...Active and poisoning-resistant Ru-based electrocatalysts for the hydrogen oxidation reaction(HOR)are designed and fabricated by integrating Cu/Ru dual single atoms and alloy CuRu nanoparticles(N-(CuRu)_(NP+SA)@NC)through a strategy involving weak chemical reduction and ammonia-assisted gas-phase nitridation.The resultant N-(CuRu)_(NP+SA)@NC electrocatalysts feature nitrogen atoms coordinated to both Cu and Ru metal atoms via strong N-metal interactions.Density functional theory calculations revealed that alloyed CuRu nanoparticles and monodispersed Cu atoms are vital for altering the electronic configuration of the host Ru elements.This finely tuned structure enhanced the adsorption of H and OH and promoted CO oxidation over the N-(CuRu)_(NP+SA)@NC electrocatalyst,resulting in high alkaline HOR activity,as evidenced by the higher exchange current density of 3.74 mA cm^(-2)and high mass activity of 3.28 mAμg_(Ru)^(-1),which are far superior to those of most Ru-based catalysts reported to date.Moreover,the N-(CuRu)_(NP+SA)@NC electrocatalysts are resistant to CO poisoning and can be used at a high concentration of 1000 ppm CO with no distinct decay in the activity,in stark contrast to the commercial Pt/C catalyst under the same conditions.展开更多
Modifying Ir by foreign metals with oxophilicity is a promising strategy to accelerate the hydrogen oxidation kinetics.However,uncontrolled enrichment and oxidative dissolution of metastable oxophilic dopants in conve...Modifying Ir by foreign metals with oxophilicity is a promising strategy to accelerate the hydrogen oxidation kinetics.However,uncontrolled enrichment and oxidative dissolution of metastable oxophilic dopants in conventional Ir-based alloys impair their activity and durability.Here,we address these challenges by atomically dispersing oxophilic Sn sites within Ir clusters to form dilute alloys.The Sn1-Ir pairs,confined within an atomic-scale lattice,prevent excessive*OH coverage caused by oxophilic site enrichment,while also reducing durability loss due to the dissolution of metastable dopants.Our analysis reveals that the Sn1-Ir pairs facilitate electron transfer between Sn1 and adjacent Ir sites,generating electron-rich Ir atoms and electron-poor Sn atoms.This modulation weakens*H and CO adsorption on Ir sites while enhancing OH adsorption on Sn sites.The resulting catalyst shows improved catalytic hydrogen oxidation performance in alkaline media,with mass activities 6.4 and 10.7 times higher than that of Ir/C and Pt/C,respectively.Under CO poisoning conditions,it retains 90.9%of its initial activity,outperforming both Ir/C and Pt/C.This work offers new perspectives on the design of dual-site catalysts for hydrogen oxidation catalysis.展开更多
The susceptibility of Pt catalyst surfaces to carbon monoxide(CO)poisoning in anodic hydrogen oxidation reaction(HOR)has been a critical constraint on the development of proton exchange membrane fuel cells(PEMFCs).Eff...The susceptibility of Pt catalyst surfaces to carbon monoxide(CO)poisoning in anodic hydrogen oxidation reaction(HOR)has been a critical constraint on the development of proton exchange membrane fuel cells(PEMFCs).Effectively regulating the electronic structure of Pt to enhance CO resistance is crucial for developing high-performance catalysts with robust anti-poisoning capabilities.Herein,the Pt/W@NCNF featured by Pt nanoparticles and atomical dispersed tungsten(W)sites on N-doped carbon nanofibers is developed for CO tolerance HOR catalyst.The presence of W enables the electron transfer from Pt,which promotes electron rearrangement in the Pt-5d orbitals.It not only optimizes the adsorption of H^(*) and CO^(*)on Pt,but also the OH^(*) intermediates adsorbed on the W sites oxidize the CO*adsorbed on Pt,thereby retaining more active sites for H_(2) adsorption and oxidation.The HOR exchange current density of Pt/W@NCNF reaches 1.35 times that of commercial Pt/C,and the limiting current density decreases by only 3.4%after introducing 1000 ppm CO in H_(2).Notably,the Pt/W@NCNF-based PEMFCs deliver markedly superior performance across a range of CO concentrations.The present study demonstrates that electronic modulation of Pt is an effective strategy for simultaneously achieving resistance to CO and promoted HOR activity.展开更多
The scarcity,high cost and susceptibility to CO of Platinum severely restrict its application in alkaline hydrogen oxidation reaction(HOR).Hybridizing Pt with other transition metals provides an effective strategy to ...The scarcity,high cost and susceptibility to CO of Platinum severely restrict its application in alkaline hydrogen oxidation reaction(HOR).Hybridizing Pt with other transition metals provides an effective strategy to modulate its catalytic HOR performance,but at the cost of mass activity due to the coverage of modifiers on Pt surface.Herein,we constructed dual junctions'Pt/nitrogen-doped carbon(Pt/NC)andδ-MoC/NC to modify electronic structure of Pt via interfacial electron transfer to acquire Pt-MoC@NC catalyst with electron-deficient Pt nanoparticles,simultaneously endowing it with high mass activity and durability of alkaline HOR.Moreover,the unique structure of Pt-MoC@NC endows Pt with a high COtolerance at 1,000 ppm CO/H_(2),a quality that commercial Pt-C catalyst lacks.The theoretical calculations not only confirm the diffusion of electrons from Pt/NC to Mo C/NC could occur,but also demonstrate the negative shift of Pt d-band center for the optimized binding energies of*H,*OH and CO.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
基金supported by Jilin Province Science and Technology Development Program(Nos.20200201001JC,20210502002ZP,20230101367JC,20220301011GX)Jilin Province Science and Technology Major Project(No.222648GX0105103875).
文摘The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),which relies on the rational regulation of intermediates’binding strength.Herein,we reported a simple strategy to manipulate the adsorption energy of OH^(∗)on electrocatalyst surface via engineering Ni/NbO_(x) heterostructures with manageable oxygen vacancy(Ov).Theoretical calculations confirm that the electronic effect between Ni and NbO_(x) could weaken the hydrogen adsorption on Ni,and the interfacial oxygen vacancy tailor hydroxide binding energy(OHBE).The optimized HBE and OHBE contribute to reduce formation energy of water during the alkaline HOR process.Furthermore,in situ Raman spectroscopy monitor the dynamic process that OH^(∗)adsorbed on oxygen vacancy and react with adjacent H^(∗)adsorbed Ni,confirming the vital role of OH^(∗)for alkaline HOR process.As a result,the optimal Ni/NbO_(x) exhibits a remarkable intrinsic activity with a specific activity of 0.036mA/cm^(2),which is 4-fold than that of pristine Ni counterpart and surpasses most non-precious electrocatalysts ever reported.
文摘The employment of single atom catalysts(SACs)remarkably increases atomic utilization and catalytic efficiency in various electrochemical processes,especially when coupled with metal clusters/nanoparticles.However,the synergistic effects mainly focus on the energetics of key intermediates during the electrocatalysis,while the properties of electrode surface and electric-double-layer(EDL)structure are largely overlooked.Herein,we report the synthesis of Ru nanoparticles integrated with neighboring Ru single atoms on nitrogen doped carbon(Ru1,n/NC)as efficient catalysts toward hydrogen oxidation reaction(HOR)under alkaline electrolytes.Electrochemical data,in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy,and density functional theory calculations reveal that the positively charged Ru single atoms could lead to the dynamically regulated proportion of strongly hydrogen-bonded interfacial water structure with O-down conformation and optimized connectivity of the hydrogen-bond network in the EDL region,which contribute to the accelerated diffusion of hydroxide ions to the electrified interfaces.Consequently,the obtained Ru1,n/NC catalyst displays remarkable HOR performance with the mass activity of 1.15 mAμgPGM^(-1) under alkaline electrolyte.This work demonstrates the promise of single atoms for interfacial water environment adjustment and mass transfer process modulation,providing new insights into rational design of highly-effective SAC-based electrocatalysts.
基金financially supported by 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.
文摘Constructing well-defined interfaces in catalysts is a highly effective method to accelerate reactions with multiple intermediates.In this study,we developed a heterostructure catalyst combining fcc NiCu and hcp Ni_(3)N,aiming at achieving superior performance in alkaline hydrogen electrocatalysis.The NiCu/Ni_(3)N not only overcomes the inadequate hydroxyl binding energy performance of NiCu alloys but also solves the problems of insufficient active sites found in most Ni/Ni_(3)N.Experimental results and density functional theoretical calculations reveal that the formation of heterostructure significantly depends on the amount of Cu.This approach effectively prevents the side effects of increased catalyst particle size,typically resulting from the high temperatures and prolonged reaction times required for conventional synthesis of Ni/Ni_(3)N.The interface of this heterostructure induces a distinctive overlapping effect that enhances the adsorption of water and lowers the energy barrier for the rate-determining step.The NiCu/Ni_(3)N catalyst shows an impressive activity of 71.8 mA mg^(-1) at an overpotential of 50 mV,a 14.7 times efficiency enhancement compared to pure Ni and comparable to that of low-loaded commercial Pt/C.This research highlights the potential of NiCu/Ni_(3)N in advancing catalyst development.
基金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.
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.
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.
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.
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financially supported by the National Natural Science Foundation of China(Nos.22205196 and U1904215)the Natural Science Foundation of Jiangsu Province(No.BK20210790)the start-up fundings from Yangzhou University
文摘Electrochemically induced surface reconstruction offers a novel approach for in situ modulation of the surface structure of nanomaterials.However,comprehensive studies on the surface reconstruction behavior of nanomaterials under diverse electrochemical operations remain limited.Here,exemplified by three electrochemical operations,including cyclic voltammetry(CV),squarewave potential(SWP)and chronoamperometry(CA),we reveal the structural evolution behavior and the corresponding electrocatalytic activity of bimetallic telluride hollow nanorods(Ir_(1-x)Ru_(x)0Te_(2)HNRs).It was found that the surface Te atoms in Ir_(1-x)Ru_(x)0Te_(2)HNRs undergo preferential leaching during the CV and SWP processes,ultimately leading to the formation of a metal alloy shell.In contrast,during the CA process,the surface reconstruction induced by Te leaching was suppressed by the adsorption of anions on the electrode surface.Electrocatalytic tests show that the CV activated Ir_(0.75)Ru_(0.25)Te_(2)HNRs exhibit excellent activity for the hydrogen oxidation reaction in 0.1 M KOH,with a mass activity of 686 Ag^(-1)at an overpotential of50 mV,which is 2.9 times higher than that of commercialPt/C catalyst.Density functional theory(DFT)computation reveals that the incorporation of Ru optimizes the hydroxyl binding energy of IrRu alloy,thus resulting in the reduced reaction energy barrier of hydrogen oxidation reaction.This work provides a new insight into the design of efficient catalysts through electrochemical surface engineering.
基金financially supported by the National Natural Science Foundation of China(Nos.21776115 and 51902140)the project from Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology,No.2024-KF-24)the open project from Key Laboratory of Advanced Electrode Materials for Novel Solar Cells for Petroleum and Chemical Industry of China(School of Chemistry and Life Science,Suzhou University of Science and Technology)
文摘Interface engineering is a prospective method for improving electrochemical performance,while efficient interfacial tuning is still difficult.Here,a series of WO_(3)-Ir catalysts with tuned interfaces were obtained from WO_(3)support with different surface states.The prepared WO_(3)-O-Ir catalyst with higher interfacial oxygen content shows excellent hydrogen oxidation reaction activity with a mass activity of 54.04 A gIr^(-1)for hydrogen oxidation reaction,which is superior to WO_(3)-W-Ir with higher tungsten content and even commercial Pt/C catalysts.Theoretical calculation and X-ray photoelectron spectroscopy valence band spectrum analyses verify that the position of the d-band center is directly proportional to the interfacial oxygen content.This modulates the electronic structure of the active phase,increasing the binding energy for OH species and enhancing their adsorption capacity,which boost the performance for hydrogen oxidation reaction.
文摘Active and poisoning-resistant Ru-based electrocatalysts for the hydrogen oxidation reaction(HOR)are designed and fabricated by integrating Cu/Ru dual single atoms and alloy CuRu nanoparticles(N-(CuRu)_(NP+SA)@NC)through a strategy involving weak chemical reduction and ammonia-assisted gas-phase nitridation.The resultant N-(CuRu)_(NP+SA)@NC electrocatalysts feature nitrogen atoms coordinated to both Cu and Ru metal atoms via strong N-metal interactions.Density functional theory calculations revealed that alloyed CuRu nanoparticles and monodispersed Cu atoms are vital for altering the electronic configuration of the host Ru elements.This finely tuned structure enhanced the adsorption of H and OH and promoted CO oxidation over the N-(CuRu)_(NP+SA)@NC electrocatalyst,resulting in high alkaline HOR activity,as evidenced by the higher exchange current density of 3.74 mA cm^(-2)and high mass activity of 3.28 mAμg_(Ru)^(-1),which are far superior to those of most Ru-based catalysts reported to date.Moreover,the N-(CuRu)_(NP+SA)@NC electrocatalysts are resistant to CO poisoning and can be used at a high concentration of 1000 ppm CO with no distinct decay in the activity,in stark contrast to the commercial Pt/C catalyst under the same conditions.
基金financially supported by the National Natural Science Foundation of China(No.12274190)Shandong Provincial Natural Science Foundation(No.ZR2024QB039)the Special Fund for Taishan Scholars Project(No.tsqn202312224 and tsqn202211186)in Shandong Province.The authors acknowledge the support of the Carbon Neutrality Innovation Research Center at Ludong University.
文摘Modifying Ir by foreign metals with oxophilicity is a promising strategy to accelerate the hydrogen oxidation kinetics.However,uncontrolled enrichment and oxidative dissolution of metastable oxophilic dopants in conventional Ir-based alloys impair their activity and durability.Here,we address these challenges by atomically dispersing oxophilic Sn sites within Ir clusters to form dilute alloys.The Sn1-Ir pairs,confined within an atomic-scale lattice,prevent excessive*OH coverage caused by oxophilic site enrichment,while also reducing durability loss due to the dissolution of metastable dopants.Our analysis reveals that the Sn1-Ir pairs facilitate electron transfer between Sn1 and adjacent Ir sites,generating electron-rich Ir atoms and electron-poor Sn atoms.This modulation weakens*H and CO adsorption on Ir sites while enhancing OH adsorption on Sn sites.The resulting catalyst shows improved catalytic hydrogen oxidation performance in alkaline media,with mass activities 6.4 and 10.7 times higher than that of Ir/C and Pt/C,respectively.Under CO poisoning conditions,it retains 90.9%of its initial activity,outperforming both Ir/C and Pt/C.This work offers new perspectives on the design of dual-site catalysts for hydrogen oxidation catalysis.
基金supported by the National Natural Science Foundation of China(22179034,22279030)the Natural Science Foundation of Heilongjiang Province(ZD2023B002).
文摘The susceptibility of Pt catalyst surfaces to carbon monoxide(CO)poisoning in anodic hydrogen oxidation reaction(HOR)has been a critical constraint on the development of proton exchange membrane fuel cells(PEMFCs).Effectively regulating the electronic structure of Pt to enhance CO resistance is crucial for developing high-performance catalysts with robust anti-poisoning capabilities.Herein,the Pt/W@NCNF featured by Pt nanoparticles and atomical dispersed tungsten(W)sites on N-doped carbon nanofibers is developed for CO tolerance HOR catalyst.The presence of W enables the electron transfer from Pt,which promotes electron rearrangement in the Pt-5d orbitals.It not only optimizes the adsorption of H^(*) and CO^(*)on Pt,but also the OH^(*) intermediates adsorbed on the W sites oxidize the CO*adsorbed on Pt,thereby retaining more active sites for H_(2) adsorption and oxidation.The HOR exchange current density of Pt/W@NCNF reaches 1.35 times that of commercial Pt/C,and the limiting current density decreases by only 3.4%after introducing 1000 ppm CO in H_(2).Notably,the Pt/W@NCNF-based PEMFCs deliver markedly superior performance across a range of CO concentrations.The present study demonstrates that electronic modulation of Pt is an effective strategy for simultaneously achieving resistance to CO and promoted HOR activity.
基金supported by the National Natural Science Foundation of China (Grant Nos.52072272,52171145 and 22109120)the Zhejiang Provincial Natural Science Foundation of China (LQ21B030002)+1 种基金the Zhejiang Provincial Special Support Program for High-level Talents (2019R52042)the Key programs for Science and Technology Innovation of Wenzhou (ZG2022037)。
文摘The scarcity,high cost and susceptibility to CO of Platinum severely restrict its application in alkaline hydrogen oxidation reaction(HOR).Hybridizing Pt with other transition metals provides an effective strategy to modulate its catalytic HOR performance,but at the cost of mass activity due to the coverage of modifiers on Pt surface.Herein,we constructed dual junctions'Pt/nitrogen-doped carbon(Pt/NC)andδ-MoC/NC to modify electronic structure of Pt via interfacial electron transfer to acquire Pt-MoC@NC catalyst with electron-deficient Pt nanoparticles,simultaneously endowing it with high mass activity and durability of alkaline HOR.Moreover,the unique structure of Pt-MoC@NC endows Pt with a high COtolerance at 1,000 ppm CO/H_(2),a quality that commercial Pt-C catalyst lacks.The theoretical calculations not only confirm the diffusion of electrons from Pt/NC to Mo C/NC could occur,but also demonstrate the negative shift of Pt d-band center for the optimized binding energies of*H,*OH and CO.
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.
