Pd-based catalysts exhibit higher catalytic activity and durability in many electrochemical reactions.However,the electrochemical performance can be further enhanced by fine-tune of the alloy composition.Although bina...Pd-based catalysts exhibit higher catalytic activity and durability in many electrochemical reactions.However,the electrochemical performance can be further enhanced by fine-tune of the alloy composition.Although binary alloys have been fully studied,the multicomponent alloys are far beyond understanding,which leaves cocktail effect a compromised explanation for the high-entropy alloy.Herein Pd nanosheet-seeded growth was used to synthesize a Pd-Zn-Cd ternary alloy by accurately controlling the Pd-Zn-Cd molar ratio through adjusting the amount of introduced Cd precursor.Through analysis of the crystal phase structure of PdCdZnx and PdZn_(x)Cd_(1-x),the competitive relationship of Zn and Cd in the alloying process with Pd was unveiled:Pd1Cd1 intermetallics(IMC)is thermodynamically favored over Pd_(1)Zn_(1)IMC in the ternary system.However,the increased structure stability of PdCd over PdZn does not bring about increased durability in the catalytic ethanol oxidation reaction.The morphology selection of Pd seeds is also crucial for the study,as Pd cubes,Pd tetrahedrons,and Pd octahedrons do not form PdZn in the same protocol.The successful alloying through the seeded growth depends on the maximum diffusion depth of foreign atoms into the seed.展开更多
Direct ethanol fuel cell(DEFC)has received tremendous research interests because of the more convenient storage and transportation of ethanol vs.compressed hydrogen.However,the electrocatalytic ethanol oxidation react...Direct ethanol fuel cell(DEFC)has received tremendous research interests because of the more convenient storage and transportation of ethanol vs.compressed hydrogen.However,the electrocatalytic ethanol oxidation reaction typically requires precious metal catalysts and is plagued with relatively high over potential and low mass activity.Here we report the synthesis of Pt3Ag alloy wavy nanowires via a particle attachment mechanism in a facile solvothermal process.Transmission microscopy studies and elemental analyses show highly wavy nanowire structures with an average diameter of 4.6±1.0 nm and uniform Pt3Ag alloy formation.Electrocatalytic studies demonstrate that the resulting alloy nanowires can function as highly effective electrocatalysts for ethanol oxidation reactions(EOR)with ultrahigh specific activity of 28.0 mA/cm^2 and mass activity of 6.1 A/mg,far exceeding that of the commercial Pt/carbon samples(1.10 A/mg).The improved electrocatalytic activity may be partly attributed to partial electron transfer from Ag to Pt in the Pt3Ag alloy,which weakens CO binding and the CO poisoning effect.The one-dimensional nanowire morphology also contributes to favorable charge transport properties that are critical for extracting charge from catalytic active sites to external circuits.The chronoamperometry studies demonstrate considerably improved stability for long term operation compared with the commercial Pt/C samples,making the Pt3Ag wavy nanowires an attractive electrocatalyst for EOR.展开更多
High-quality Pt-based catalysts are highly desirable for ethanol oxidation reaction(EOR),which is of critical importance for the commercial applications of direct ethanol fuel cells(DEFCs).However,most of the Pt-based...High-quality Pt-based catalysts are highly desirable for ethanol oxidation reaction(EOR),which is of critical importance for the commercial applications of direct ethanol fuel cells(DEFCs).However,most of the Pt-based catalysts have suffered from high cost and low operation durability.Herein a two-step method has been developed to synthesize porous Pt nanoframes decorated with Bi(OH)3,which show excellent catalytic activity and operation durability in both alkaline and acidic media.For example,the nanoframes show a mass activity of 6.87 A·mgPt−1 in alkaline media,which is 13.5-fold higher than that of commercial Pt/C.More importantly,the catalyst can be reactivated simply,which shows negligible activity loss after running for 180,000 s.Further in situ attenuated total reflection-infrared(ATR-IR)absorption spectroscopy and CO-stripping experiments indicate that surface Bi(OH)3 species can greatly facilitate the formation of adsorbed OH species and subsequently remove carbonaceous poison,resulting in a significantly enhanced stability towards EOR.This work may favor the tailoring of desired electrocatalysts with high activity and durability for future commercial application of DEFCs.展开更多
The catalytic performance of Pt-based catalysts depends sensitively on their d-band centers.Nevertheless,there are still huge challenges to evaluate their d-band centers from experimental technologies,and modulate the...The catalytic performance of Pt-based catalysts depends sensitively on their d-band centers.Nevertheless,there are still huge challenges to evaluate their d-band centers from experimental technologies,and modulate them to analyze their selectivity in ethanol oxidation reaction(EOR).Here,Pt1Au1alloy supported on the commercial carbon material(Pt_(1)Au_(1)/C)is employed as a typical example to investigate its d-band center shift of surface Pt,and as electrocatalysts to study its selectivity towards EOR.Significantly,a highly reliable in situ Fourier-transform infrared spectroscopy CO-probe strategy is developed to characterize the d-band center shift of surface Pt.The modified electronic effect and site effect of Pt_(1)Au_(1)/C dictated the adsorption configuration of intermediate species and the OH species coverage,thereby influencing its selectivity.More importantly,we developed a universal cyclic voltammetry peak differentiation fitting method as an electrochemical analysis technique to investigate CO_(2)selectivity,which is potentially extendable to other Pt-based electrocatalysts.展开更多
Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially ad...Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.展开更多
Crystal phase can greatly affect the physicochemical properties and applications of nanomaterials.However,it stil remains a great challenge to synthesize nanostructures with the same composition and morphology but dif...Crystal phase can greatly affect the physicochemical properties and applications of nanomaterials.However,it stil remains a great challenge to synthesize nanostructures with the same composition and morphology but different phases in order to explore the phase-dependent properties and applications.Herein,we report the crystal phase-controlled synthesis of PtCu alloy shells on 4H Au nanoribbons(NRBs),referred to as 4H-Au NRBs,to form the 4H-Au@PtCu core-shell NRBs.By tuning the thickness of PtCu,4H-PtCu and face-centered cubic(cc)phase PICu(cc-PtCu)alloy shells are successtully grown on the 4H-Au NRB cores.This thickness-dependent phase-controlled growth strategy can also be used to grow PtCo alloys with 4H or fcc phase on 4H-Au NRBs.Significantly,when used as electrocatalysts for the ethanol oxidation reaction(EOR)in alkaline media,the 4H-Au@4H-PtCu NRBs show much better EOR performance than the 4H-Au@fcc-PtCu NRBs,and both of them possess superior performance compared to the commercial Pt black.Our study provides a strategy on phase-contolled synthesis of nanomaterials used for crystal phase-dependent applications.展开更多
metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C s...metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C speciessupported Pd nanoparticles(Pd-MoO_(3)/C)using a convenient hydrothermal method,which exhibited excellent catalytic activities for both ethanol oxidation and oxygen reduction in KOH media.The specific activity of PdMoO_(3)/C toward ethanol oxidation with MoO_(3)loading(40wt%)was~2.6 times greater than that for the commercial Pd/C(10 wt%)with the same Pd content.In particular,the activity could effectively hold up to~60%of its maximum activity after 500-cycle tests,demonstrating improved cyclical stability.Notably,the fast electron transfer kinetics toward oxygen reduction for Pd-MoO_(3)/C(40%)were also comparable to those of commercial Pt/C(20 wt%)catalysts.These superior electrochemical features are primarily derived from the stronger electronic coupling between Pd and MoO_(3)through charge transfer,which can supply more active centers and improve the anti-poisoning ability.Meanwhile,the MoO_(3)species in the Pd-MoO_(3)/C composite may provide additional benefits in terms of electrical conductivity and dispersion.展开更多
The catalysis of Au thin film could be improved by fabrication of array structures in large area.In this work,nanoimprint lithography has been developed tofabricate flexible Au micro-array(MA)electrodes with~100%cover...The catalysis of Au thin film could be improved by fabrication of array structures in large area.In this work,nanoimprint lithography has been developed tofabricate flexible Au micro-array(MA)electrodes with~100%coverage.Advanced electron microscopy characterisations have directly visualised the atomic-scale three-dimensional(3D)nanostructures with a maximum depth of 6 atomic layers.In-situ observation unveils the crystal growth in the form of twinning.High double layer capacitance brings about large number of active sites on the Au thin film and has a logarithmic relationship with mesh grade.Electrochemistry testing shows that the Au MAs perform much better ethanol oxidation reaction than the planar sample;MAs with higher mesh grade have a greater active site utilisation ratio(ASUR),which is important to build electrochemical double layer for efficient charge transfer.Further improvement on ASUR is expected for greater electrocatalytic performance and potential application in direct ethanol fuel cell.展开更多
The creation of anodic ethanol oxidation reaction catalysts with superior all-around performance for direct ethanol fuel cells(DEFCs)has continued to attract the attention of researchers.An ultrathin trimetallic PtAuB...The creation of anodic ethanol oxidation reaction catalysts with superior all-around performance for direct ethanol fuel cells(DEFCs)has continued to attract the attention of researchers.An ultrathin trimetallic PtAuBi aerogel with branching,rough-surfaced 1D nanowires that self-assemble into a 3D porous network structure has been created in this study.It has a mass activity(MA)of 8045 mA mgPt^(-1)in an alkaline medium,which is 7.56 times greater than that of commercial Pt/C(1064 mA mgPt^(-1)).Notably,the catalytic activity and resistance to CO poisoning of PtAuBi aerogels are improved by the addition of an efficient"active additive"Au.The results analysis reveals that the increased performance of PtAuBi aerogel is mostly attributable to the integrated function of the 3D porous network structure,the downward shift of the Pt d-band center,and the synergistic effect of the"Pt-Bi"and/or"Pt-Au"dual active sites.展开更多
Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batte...Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batteries.However,the effect of the dynamic surface evolution of the catalyst in operating conditions on the activity of EOR lacks comprehensive understanding.Herein,we demonstrate a tunable operational catalyst activity through the modulated redox property of nickel oxalate(NCO)by establishing a relation between the oxidation behavior of Ni,surface reconstruction,and catalyst activity.We propose a repeated chemical-electrochemical reaction mechanism of EOR on NCO,which is rigorously investigated through a combination of operando Raman and nuclear magnetic resonance.The modulation of the oxidation trend of Ni by doping heteroatoms stimulates the electrochemical oxidation of the catalyst surface to NiOOH,which alters the catalyst activity for EOR.Assembled ethanol-assisted water electrolysis cell exhibits a reduced operating voltage for hydrogen production by 200 mV with a~100% Faradaic efficiency,and zinc-ethanol-air battery showed a 287 mV decreased charge-discharge voltage window and enhanced stability for over 500 h.展开更多
The widespread application of direct ethanol fuel cells is hampered due to the low activity,high cost and poor operation durability of electrocatalysts for ethanol oxidation reaction(EOR).Herein,we report a one-pot sy...The widespread application of direct ethanol fuel cells is hampered due to the low activity,high cost and poor operation durability of electrocatalysts for ethanol oxidation reaction(EOR).Herein,we report a one-pot synthetic method to synthesize PdPb3 nanochains with well-defined shape,size and composition via a solution-phase reduction method.The morphology,composition distribution and structure characteristics of PdPb3 nanochains were investigated by transmission electron microscopy,X-ray photoelectron spectroscopy and X-ray diffraction.Thanks to the unique structure,the as-obtained PdPb3 nanochains can manifest much higher mass activity(2523 mA·mg-1)and higher operation durability than commercial Pd/C(1272 mA·mg-1)during the EOR measurements.More importantly,further CO-stripping measurements indicate that the incorporation of Pb species could favor the oxidative removal of CO intermediates on the Pd electrode at the negative potential and enhance the EOR activity and stability,making it possible to develop highly active and durable electrocatalysts.展开更多
Rational design of low‐cost and efficient electrocatalysts for ethanol oxidation reaction(EOR)is imperative for electrocatalytic ethanol fuel cells.In this work,we developed a copper‐doped nickel oxyhydroxide(Cu‐do...Rational design of low‐cost and efficient electrocatalysts for ethanol oxidation reaction(EOR)is imperative for electrocatalytic ethanol fuel cells.In this work,we developed a copper‐doped nickel oxyhydroxide(Cu‐doped NiOOH)catalyst via in situ electrochemical reconstruction of a NiCu alloy.The introduction of Cu dopants increases the specific surface area and more defect sites,as well as forms high‐valence Ni sites.The Cu‐doped NiOOH electrocatalyst exhibited an excellent EOR performance with a peak current density of 227 mA·cm^(–2)at 1.72 V versus reversible hydrogen electrode,high Faradic efficiencies for acetate production(>98%),and excellent electrochemical stability.Our work suggests an attractive route of designing non‐noble metal based electrocatalysts for ethanol oxidation.展开更多
To maximize the size and structural advantages of nanomaterials in electrooxidation of ethanol, we herein report the synthesis of core–shell gold(Au)@Palladium(Pd) nanoparticles smaller than 3 nm in an ionic liquid, ...To maximize the size and structural advantages of nanomaterials in electrooxidation of ethanol, we herein report the synthesis of core–shell gold(Au)@Palladium(Pd) nanoparticles smaller than 3 nm in an ionic liquid, which combines the advantages of ionic liquids in preparing fine metal nanoparticles with the benefits of core–shell nanostructures. This synthetic strategy relies on the use of an ionic liquid(1-(2'-aminoethyl)-3-methyl-imidazolum tetrafluoroborate) as a stabilizer to produce Au particles with an average size of ca. 2.41 nm, which are then served as seeds for the formation of tiny core–shell Au@Pd nanoparticles with different Au/Pd molar ratios. The strong electronic coupling between Au core and Pd shell endows the Pd shell with an electronic structure favorable for the ethanol oxidation reaction. In specific, the ionic liquidderived core–shell Au@Pd nanoparticles at an Au/Pd molar ratio of 1/1 exhibit the highest mass-and area-based activities, approximately 11 times than those of commercial Pd/C catalyst for ethanol electrooxidation.展开更多
The application of direct ethanol fuel cell(DEFC)has been bottlenecked by the sluggish ethanol oxidation reaction(EOR).Efficient electrocatalysts for the C-C bond cleavage are essential to promote EOR with high effici...The application of direct ethanol fuel cell(DEFC)has been bottlenecked by the sluggish ethanol oxidation reaction(EOR).Efficient electrocatalysts for the C-C bond cleavage are essential to promote EOR with high efficiency and C1 selectivity.Here,we prepared Rh-Cu alloy nano-dendrites(RhCu NDs)with abundant surface steps through controlled co-reduction,which exhibited significantly enhanced activity and C1 selectivity(0.47 m A cm_((ECSA))^(-2),472.4 mA mg_(Rh)^(-1),and 38.9%)than Rh NDs(0.32 mA cm((ECSA))-2,322.1 mA mgRh-1,and 21.4%)and commercially available Rh/C(0.18 mA cm_((ECSA))^(-2),265.4 mA mg_(Rh)^(-1),and 14.9%).Theoretical calculations and CO-stripping experiments revealed that alloying with Cu could modulate the surface electronic structures of Rh to resist CO-poisoning while strengthening ethanol adsorption.In situ Fourier transform infrared spectroscopy(FTIR)indicated that the surface steps on RhCu NDs further promoted the C-C bond cleavage to increase the C1 selectivity.Therefore,optimizing the surface geometric and electronic structures of nanocrystals by rational composition and morphology control can provide a promising strategy for developing practical DEFC devices.展开更多
Atomic surface engineering for nanostructures significantly contributes to the enhancement of electrocatalysis for a given chemical reaction.However,exploring a facile method to elaborately regulate surfaces at atomic...Atomic surface engineering for nanostructures significantly contributes to the enhancement of electrocatalysis for a given chemical reaction.However,exploring a facile method to elaborately regulate surfaces at atomic scale remains a grand challenge.Herein,we report the construction of atomically rough surfaces(ARSs)on Au-based binary alloys through a novel and controllable gold(Au)-catalyzed strategy,which involves the first synthesis of Au-based bimetallic nanoalloys,i.e.,AuPd and AuAg,and subsequent reduction of another metal ions(Pt,Pd,or Ag)initiated by Au sites on the alloy particle surfaces.By combining ARSs with low-coordinated atoms with ligand effect induced by vicinal Au atoms,the as-prepared ARSs exhibit good activity and durability toward ethanol oxidation reaction(EOR)in an alkaline medium.In particular,the Pd-Pt ARSs on the AuPd alloy particle surface(denoted as AuPd-Pt)exhibit the highest electrocatalytic EOR performance in terms of both specific activity(14.9 mA cm^(–2))and mass activity(28.5 A mg^(–1)),surpassing those of their AuPd alloy counterparts,commercial Pd/C catalyst,and most Pd-based electrocatalysts reported recently.In situ Fourier transform infrared(FTIR)spectroscopy reveals that the EOR process on the Pd-Pt ARSs strongly prefers incomplete oxidation,which is further authenticated by the density functional theory(DFT)calculations.展开更多
The construction of bimetallic sites with strong interaction can effectively regulate the electronic structure and modulate the adsorption behavior of adsorbate species on bimetallic catalysts,thereby overcoming catal...The construction of bimetallic sites with strong interaction can effectively regulate the electronic structure and modulate the adsorption behavior of adsorbate species on bimetallic catalysts,thereby overcoming catalytic bottlenecks.Herein,an RhPb bimetallene(RhPb b-ML)with the strong d-p orbital hybridization is proposed for efficiently catalyzing ethanol oxidation reaction(EOR).Notably,the specific EOR activity of RhPb b-ML is 32 and 6.8 times higher than those of Rh metallene and commercial Pt/C,respectively.Theoretical calculation analysis reveals that the introduction of Pb atoms into the Rh lattice leads to an upward shift of the d-band center of Rh on RhPb(111).The shift in the d-band center is primarily attributed to the different degrees of hybridization between the d sub-orbitals of Rh and the p-orbitals of Pb,which enhance the adsorption of key species and improve EOR activity and selectivity.In-situ infrared tests and high-performance liquid chromatography tests together confirm that RhPb b-ML not only exhibits enhanced ability for the breakage of C-C bonds but also effectively suppresses the generation of absorbed CO.Furthermore,the strategy of enhancing catalyst performance through the strong d-p orbital hybridization has been demonstrated to be scalable to other bimetallic catalysts,providing valuable insights for the design of advanced catalysts.展开更多
Nucleophile oxidation reaction(NOR),represented by ethanol oxidation reaction(EOR),is a promising pathway to replace oxygen evolution reaction(OER).EOR can effectively reduce the driving voltage of hydrogen production...Nucleophile oxidation reaction(NOR),represented by ethanol oxidation reaction(EOR),is a promising pathway to replace oxygen evolution reaction(OER).EOR can effectively reduce the driving voltage of hydrogen production in direct water splitting.In this work,large current and high efficiency of EOR on a Ni,Fe layered double hydroxide(NiFe-LDH)catalyst were simultaneously achieved by a facile fluorination strategy.F in NiFe-LDH can reduce the activation energy of the dehydrogenation reaction,thus promoting the deprotonation process of NiFe-LDH to achieve a lower EOR onset potential.It also weakens the absorption of OH-and nucleophile electrooxidation products on the surface of NiFe-LDH at a higher potential,achieving a high current density and EOR selectivity,according to density functional theory calculations.Based on our experiment results,the optimized fluorinated NiFe-LDH catalyst achieves a low potential of 1.386 V to deliver a 10 mA cm^(-2)EOR.Moreover,the Faraday efficiency is greater than 95%,with a current density ranging from 10 to 250 mA cm^(-2).This work provides a promising pathway for an efficient and cost-effective NOR catalyst design for economic hydrogen production.展开更多
Dealloying by which the transition metal is partially or completely leached from an alloy precursor is an effective way to optimize the fundamental effects for further enhancing the electrocatalysis of a catalyst.Here...Dealloying by which the transition metal is partially or completely leached from an alloy precursor is an effective way to optimize the fundamental effects for further enhancing the electrocatalysis of a catalyst.Herein,to address the deficiencies associated with the commonly used dealloying methods,for example,electrochemical and sulfuric acid/nitric acid treatment,we report an acetic acid-assisted mild strategy to dealloy Cu atoms from the outer surface layers of CuPd alloy nanoparticles to achieve high-efficiency electrocatalysis for oxygen reduction and ethanol oxidation in an alkaline electrolyte.The leaching of Cu atoms by acetic acid exerts an additional compressive strain effect on the surface layers and exposes more active Pd atoms,which is beneficial for boosting the catalytic performance of a dealloyed catalyst for the oxygen reduction reaction(ORR)and the ethanol oxidation reaction(EOR).In particular,for ORR,the CuPd nanoparticles with a Pd/Cu molar ratio of 2:1 after acetic dealloying show a half-wave potential of 0.912 V(vs.RHE)and a mass activity of 0.213 AmgPd^(-1)at 0.9 V,respectively,while for EOR,the same dealloyed sample has a mass activity and a specific activity of 8.4 Amg^(-1)and 8.23 mA cm^(-2),respectively,much better than their dealloyed counterparts at other temperatures and commercial Pd/C as well as a Pt/C catalyst.展开更多
The main problem faced by ethanol oxidation reaction(EOR)includes low activity,poor selectivity,and durability.In the study,we found that polysulfide modified on the surface of PtCu intermetallic(IM)/C can simultaneou...The main problem faced by ethanol oxidation reaction(EOR)includes low activity,poor selectivity,and durability.In the study,we found that polysulfide modified on the surface of PtCu intermetallic(IM)/C can simultaneously enrich hydroxyl and ethanol,which could effectively improve the catalytic activity,CO_(2) selectivity,and durability of catalyst.The mass activity and the specific activity of the product in 1 M KOH electrolyte reached 17.83 A·mgPt^(-1) and 24.67 mA·cm^(-2).The CO_(2) selectivity of polysulfide modified product achieved 93.5%,which was 30 folds higher than Pt/C.In addition,the catalyst showed high catalytic stability.The mechanism study demonstrates that the surface modified polysulfide could significantly boost the enrichment effect of ethanol and hydroxyl species,accelerating C–C bond cleavage and CO oxidation.展开更多
The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into electricity.Despite efforts,most Pt-based catalysts still suffer from d...The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into electricity.Despite efforts,most Pt-based catalysts still suffer from drawbacks such as poor activity and susceptibility to CO poisoning,particularly in acidic conditions.Herein,we employed a physical laser-assisted approach to synthetize a PtPd alloy with a 1:1 atomic ratio.This alloy demonstrates remarkable performance in acidic EOR,boasting a high mass activity of 1.86 A·mgPt^(−1)and competitive resistance to poisoning.Combining in situ synchrotron radiation infrared spectroscopy with theoretical calculations,we reveal that the synergic interaction between Pt and Pd enhances both the adsorption of OH*intermediate and the dehydrogenation ability of ethanol.This work will prove the feasibility of synthesizing bimetallic alloys by a physical laser-assisted strategy and promote the development of advanced alloy electrocatalysts.展开更多
基金the support of National Natural Science Foundation of China(No.22175127).
文摘Pd-based catalysts exhibit higher catalytic activity and durability in many electrochemical reactions.However,the electrochemical performance can be further enhanced by fine-tune of the alloy composition.Although binary alloys have been fully studied,the multicomponent alloys are far beyond understanding,which leaves cocktail effect a compromised explanation for the high-entropy alloy.Herein Pd nanosheet-seeded growth was used to synthesize a Pd-Zn-Cd ternary alloy by accurately controlling the Pd-Zn-Cd molar ratio through adjusting the amount of introduced Cd precursor.Through analysis of the crystal phase structure of PdCdZnx and PdZn_(x)Cd_(1-x),the competitive relationship of Zn and Cd in the alloying process with Pd was unveiled:Pd1Cd1 intermetallics(IMC)is thermodynamically favored over Pd_(1)Zn_(1)IMC in the ternary system.However,the increased structure stability of PdCd over PdZn does not bring about increased durability in the catalytic ethanol oxidation reaction.The morphology selection of Pd seeds is also crucial for the study,as Pd cubes,Pd tetrahedrons,and Pd octahedrons do not form PdZn in the same protocol.The successful alloying through the seeded growth depends on the maximum diffusion depth of foreign atoms into the seed.
基金X.E D.acknowledges support from National Science Foundation award 1800580.Y.H.acknowledges support from Office of Naval Research grant N000141812155.X.Q.P.acknowledge the support from the National Science Foundation award DMR-1506535.HAADF imaging and EDS mapping were carried out using the JEOL Grand ARM in the Irvine Materials Research Institute at the University of California,Irvine.
文摘Direct ethanol fuel cell(DEFC)has received tremendous research interests because of the more convenient storage and transportation of ethanol vs.compressed hydrogen.However,the electrocatalytic ethanol oxidation reaction typically requires precious metal catalysts and is plagued with relatively high over potential and low mass activity.Here we report the synthesis of Pt3Ag alloy wavy nanowires via a particle attachment mechanism in a facile solvothermal process.Transmission microscopy studies and elemental analyses show highly wavy nanowire structures with an average diameter of 4.6±1.0 nm and uniform Pt3Ag alloy formation.Electrocatalytic studies demonstrate that the resulting alloy nanowires can function as highly effective electrocatalysts for ethanol oxidation reactions(EOR)with ultrahigh specific activity of 28.0 mA/cm^2 and mass activity of 6.1 A/mg,far exceeding that of the commercial Pt/carbon samples(1.10 A/mg).The improved electrocatalytic activity may be partly attributed to partial electron transfer from Ag to Pt in the Pt3Ag alloy,which weakens CO binding and the CO poisoning effect.The one-dimensional nanowire morphology also contributes to favorable charge transport properties that are critical for extracting charge from catalytic active sites to external circuits.The chronoamperometry studies demonstrate considerably improved stability for long term operation compared with the commercial Pt/C samples,making the Pt3Ag wavy nanowires an attractive electrocatalyst for EOR.
基金supported by the National Key R&D Program of China(No.2016YFE0129600)the National Natural Science Foundation of China(Nos.21673150 and 21703146)+1 种基金the financial support from the 111 Project,Collaborative Innovation Center of Suzhou Nano Science and Technology(NANO-CIC)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘High-quality Pt-based catalysts are highly desirable for ethanol oxidation reaction(EOR),which is of critical importance for the commercial applications of direct ethanol fuel cells(DEFCs).However,most of the Pt-based catalysts have suffered from high cost and low operation durability.Herein a two-step method has been developed to synthesize porous Pt nanoframes decorated with Bi(OH)3,which show excellent catalytic activity and operation durability in both alkaline and acidic media.For example,the nanoframes show a mass activity of 6.87 A·mgPt−1 in alkaline media,which is 13.5-fold higher than that of commercial Pt/C.More importantly,the catalyst can be reactivated simply,which shows negligible activity loss after running for 180,000 s.Further in situ attenuated total reflection-infrared(ATR-IR)absorption spectroscopy and CO-stripping experiments indicate that surface Bi(OH)3 species can greatly facilitate the formation of adsorbed OH species and subsequently remove carbonaceous poison,resulting in a significantly enhanced stability towards EOR.This work may favor the tailoring of desired electrocatalysts with high activity and durability for future commercial application of DEFCs.
基金granted by the National Natural Science Foundation of China(22172134,22288102,22279011)Fundamental Research Funds for the Central Universities(2022CDJXY-003)。
文摘The catalytic performance of Pt-based catalysts depends sensitively on their d-band centers.Nevertheless,there are still huge challenges to evaluate their d-band centers from experimental technologies,and modulate them to analyze their selectivity in ethanol oxidation reaction(EOR).Here,Pt1Au1alloy supported on the commercial carbon material(Pt_(1)Au_(1)/C)is employed as a typical example to investigate its d-band center shift of surface Pt,and as electrocatalysts to study its selectivity towards EOR.Significantly,a highly reliable in situ Fourier-transform infrared spectroscopy CO-probe strategy is developed to characterize the d-band center shift of surface Pt.The modified electronic effect and site effect of Pt_(1)Au_(1)/C dictated the adsorption configuration of intermediate species and the OH species coverage,thereby influencing its selectivity.More importantly,we developed a universal cyclic voltammetry peak differentiation fitting method as an electrochemical analysis technique to investigate CO_(2)selectivity,which is potentially extendable to other Pt-based electrocatalysts.
基金This work was supported by the National Natural Science Foundation of China(Nos.51922073 and 21902109)the Natural Science Foundation of Jiangsu Province(Nos.BK20200960 and BK20180097)+1 种基金the Natural Science Foundation of Higher Education in Jiangsu Province(No.20KJB150041)the Natural Science Foundation of Nantong University for High-Level Talent(No.03083033).
文摘Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.
基金MOE under AcRF Tier 2(Nos.MOE2016-T2-2-103 and MOE2017-T2-1-162)NTU under Start-Up Grant(No.M4081296.070.500000)in Singapore+2 种基金We would like to acknowledge the Facility for Analysis,Characterization,Testing and Simulation,Nanyang Technological University,Singapore,for use of their electron microscopy and X-ray facilities.Z.X.F.and H.Z.thank the financial support from ITC via Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM)acknowledge the start-up grants(Nos.9380100,9610480 and 7200651)grants(Nos.9610478 and 1886921)in City University of Hong Kong.
文摘Crystal phase can greatly affect the physicochemical properties and applications of nanomaterials.However,it stil remains a great challenge to synthesize nanostructures with the same composition and morphology but different phases in order to explore the phase-dependent properties and applications.Herein,we report the crystal phase-controlled synthesis of PtCu alloy shells on 4H Au nanoribbons(NRBs),referred to as 4H-Au NRBs,to form the 4H-Au@PtCu core-shell NRBs.By tuning the thickness of PtCu,4H-PtCu and face-centered cubic(cc)phase PICu(cc-PtCu)alloy shells are successtully grown on the 4H-Au NRB cores.This thickness-dependent phase-controlled growth strategy can also be used to grow PtCo alloys with 4H or fcc phase on 4H-Au NRBs.Significantly,when used as electrocatalysts for the ethanol oxidation reaction(EOR)in alkaline media,the 4H-Au@4H-PtCu NRBs show much better EOR performance than the 4H-Au@fcc-PtCu NRBs,and both of them possess superior performance compared to the commercial Pt black.Our study provides a strategy on phase-contolled synthesis of nanomaterials used for crystal phase-dependent applications.
基金financially supported by the Natural Science Foundation of Shanxi Province(No.201901D111277)the National Natural Science Foundation of China(No.21571119)+1 种基金the Graduate Science and Technology Innovation Project Foundation of Shanxi Normal University(No.2021DCXM71)the Program for New Century Excellent Talents in University(No.NCET-12-1035)。
文摘metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C speciessupported Pd nanoparticles(Pd-MoO_(3)/C)using a convenient hydrothermal method,which exhibited excellent catalytic activities for both ethanol oxidation and oxygen reduction in KOH media.The specific activity of PdMoO_(3)/C toward ethanol oxidation with MoO_(3)loading(40wt%)was~2.6 times greater than that for the commercial Pd/C(10 wt%)with the same Pd content.In particular,the activity could effectively hold up to~60%of its maximum activity after 500-cycle tests,demonstrating improved cyclical stability.Notably,the fast electron transfer kinetics toward oxygen reduction for Pd-MoO_(3)/C(40%)were also comparable to those of commercial Pt/C(20 wt%)catalysts.These superior electrochemical features are primarily derived from the stronger electronic coupling between Pd and MoO_(3)through charge transfer,which can supply more active centers and improve the anti-poisoning ability.Meanwhile,the MoO_(3)species in the Pd-MoO_(3)/C composite may provide additional benefits in terms of electrical conductivity and dispersion.
基金the MOE AcRF Tier 1 grant M4011528.The XRD and FEG-TEM characterisations were performed at Facility for Analysis,Characterisation,Testing and Simulation(FACTS)Labthe FEG-SEM/FIB characterisations were carried out at Microelectronics Reliability and Characterisation(MRC)Lab.
文摘The catalysis of Au thin film could be improved by fabrication of array structures in large area.In this work,nanoimprint lithography has been developed tofabricate flexible Au micro-array(MA)electrodes with~100%coverage.Advanced electron microscopy characterisations have directly visualised the atomic-scale three-dimensional(3D)nanostructures with a maximum depth of 6 atomic layers.In-situ observation unveils the crystal growth in the form of twinning.High double layer capacitance brings about large number of active sites on the Au thin film and has a logarithmic relationship with mesh grade.Electrochemistry testing shows that the Au MAs perform much better ethanol oxidation reaction than the planar sample;MAs with higher mesh grade have a greater active site utilisation ratio(ASUR),which is important to build electrochemical double layer for efficient charge transfer.Further improvement on ASUR is expected for greater electrocatalytic performance and potential application in direct ethanol fuel cell.
基金supported by the National Natural Science Foundation of China(91745112)the Science and Technology Commission of Shanghai Municipality(22010501200,21ZR1425000,19DZ2271100).
文摘The creation of anodic ethanol oxidation reaction catalysts with superior all-around performance for direct ethanol fuel cells(DEFCs)has continued to attract the attention of researchers.An ultrathin trimetallic PtAuBi aerogel with branching,rough-surfaced 1D nanowires that self-assemble into a 3D porous network structure has been created in this study.It has a mass activity(MA)of 8045 mA mgPt^(-1)in an alkaline medium,which is 7.56 times greater than that of commercial Pt/C(1064 mA mgPt^(-1)).Notably,the catalytic activity and resistance to CO poisoning of PtAuBi aerogels are improved by the addition of an efficient"active additive"Au.The results analysis reveals that the increased performance of PtAuBi aerogel is mostly attributable to the integrated function of the 3D porous network structure,the downward shift of the Pt d-band center,and the synergistic effect of the"Pt-Bi"and/or"Pt-Au"dual active sites.
基金supported by the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(NRF-2022M3H4A1A04076616 and NRF-2022M3H4A1A01008918)a cooperation project of“Basic project(referring to projects performed with the budget directly contributed by the Government to achieve the purposes of establishment of Government–funded research Institutes)”supported by the Korea Research Institute of Chemical Technology(KRICT).
文摘Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batteries.However,the effect of the dynamic surface evolution of the catalyst in operating conditions on the activity of EOR lacks comprehensive understanding.Herein,we demonstrate a tunable operational catalyst activity through the modulated redox property of nickel oxalate(NCO)by establishing a relation between the oxidation behavior of Ni,surface reconstruction,and catalyst activity.We propose a repeated chemical-electrochemical reaction mechanism of EOR on NCO,which is rigorously investigated through a combination of operando Raman and nuclear magnetic resonance.The modulation of the oxidation trend of Ni by doping heteroatoms stimulates the electrochemical oxidation of the catalyst surface to NiOOH,which alters the catalyst activity for EOR.Assembled ethanol-assisted water electrolysis cell exhibits a reduced operating voltage for hydrogen production by 200 mV with a~100% Faradaic efficiency,and zinc-ethanol-air battery showed a 287 mV decreased charge-discharge voltage window and enhanced stability for over 500 h.
基金financially supported by the National Natural Science Foundation of China(Nos.21673150,21703146 and 51802206)the Natural Science Foundation of Jiangsu Province(Nos.BK20180097 and BK20180846)+2 种基金the Program of the Ministry of Education of China for Introducing Talents of Discipline to Universities(111 Project)the Collaborative Innovation Center of Suzhou Nano Science and Technology(NANO-CIC)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘The widespread application of direct ethanol fuel cells is hampered due to the low activity,high cost and poor operation durability of electrocatalysts for ethanol oxidation reaction(EOR).Herein,we report a one-pot synthetic method to synthesize PdPb3 nanochains with well-defined shape,size and composition via a solution-phase reduction method.The morphology,composition distribution and structure characteristics of PdPb3 nanochains were investigated by transmission electron microscopy,X-ray photoelectron spectroscopy and X-ray diffraction.Thanks to the unique structure,the as-obtained PdPb3 nanochains can manifest much higher mass activity(2523 mA·mg-1)and higher operation durability than commercial Pd/C(1272 mA·mg-1)during the EOR measurements.More importantly,further CO-stripping measurements indicate that the incorporation of Pb species could favor the oxidative removal of CO intermediates on the Pd electrode at the negative potential and enhance the EOR activity and stability,making it possible to develop highly active and durable electrocatalysts.
文摘Rational design of low‐cost and efficient electrocatalysts for ethanol oxidation reaction(EOR)is imperative for electrocatalytic ethanol fuel cells.In this work,we developed a copper‐doped nickel oxyhydroxide(Cu‐doped NiOOH)catalyst via in situ electrochemical reconstruction of a NiCu alloy.The introduction of Cu dopants increases the specific surface area and more defect sites,as well as forms high‐valence Ni sites.The Cu‐doped NiOOH electrocatalyst exhibited an excellent EOR performance with a peak current density of 227 mA·cm^(–2)at 1.72 V versus reversible hydrogen electrode,high Faradic efficiencies for acetate production(>98%),and excellent electrochemical stability.Our work suggests an attractive route of designing non‐noble metal based electrocatalysts for ethanol oxidation.
基金supported by the National Natural Science Foundation of China(21573240,21706265,21776292)National Natural Science Foundation of Beijing(2173062)+1 种基金the Center for Mesoscience,Institute of Process Engineering,Chinese Academy of Sciences(MPCS-2017-A-02)State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences(MPCS2019-A-09)。
文摘To maximize the size and structural advantages of nanomaterials in electrooxidation of ethanol, we herein report the synthesis of core–shell gold(Au)@Palladium(Pd) nanoparticles smaller than 3 nm in an ionic liquid, which combines the advantages of ionic liquids in preparing fine metal nanoparticles with the benefits of core–shell nanostructures. This synthetic strategy relies on the use of an ionic liquid(1-(2'-aminoethyl)-3-methyl-imidazolum tetrafluoroborate) as a stabilizer to produce Au particles with an average size of ca. 2.41 nm, which are then served as seeds for the formation of tiny core–shell Au@Pd nanoparticles with different Au/Pd molar ratios. The strong electronic coupling between Au core and Pd shell endows the Pd shell with an electronic structure favorable for the ethanol oxidation reaction. In specific, the ionic liquidderived core–shell Au@Pd nanoparticles at an Au/Pd molar ratio of 1/1 exhibit the highest mass-and area-based activities, approximately 11 times than those of commercial Pd/C catalyst for ethanol electrooxidation.
基金the financial support from the National Natural Science Foundation of China(Nos.21971012,21922502,21971017)the National Key Research and Development Program of China(No.2020YFB1506300)+1 种基金the Beijing Municipal Natural Science Foundation(No.JQ20007)the Beijing Institute of Technology Research Fund Program。
文摘The application of direct ethanol fuel cell(DEFC)has been bottlenecked by the sluggish ethanol oxidation reaction(EOR).Efficient electrocatalysts for the C-C bond cleavage are essential to promote EOR with high efficiency and C1 selectivity.Here,we prepared Rh-Cu alloy nano-dendrites(RhCu NDs)with abundant surface steps through controlled co-reduction,which exhibited significantly enhanced activity and C1 selectivity(0.47 m A cm_((ECSA))^(-2),472.4 mA mg_(Rh)^(-1),and 38.9%)than Rh NDs(0.32 mA cm((ECSA))-2,322.1 mA mgRh-1,and 21.4%)and commercially available Rh/C(0.18 mA cm_((ECSA))^(-2),265.4 mA mg_(Rh)^(-1),and 14.9%).Theoretical calculations and CO-stripping experiments revealed that alloying with Cu could modulate the surface electronic structures of Rh to resist CO-poisoning while strengthening ethanol adsorption.In situ Fourier transform infrared spectroscopy(FTIR)indicated that the surface steps on RhCu NDs further promoted the C-C bond cleavage to increase the C1 selectivity.Therefore,optimizing the surface geometric and electronic structures of nanocrystals by rational composition and morphology control can provide a promising strategy for developing practical DEFC devices.
基金supported by the National Natural Science Foundation of China(22272179,22075290,and 42307326)the Natural Science Foundation of Hebei Province(E2021203005 and B2021203016)+2 种基金Department of Education of Hebei Province(BJ2021042)Chinese Academy of Sciences Project for Young Scientists in Basic Research(YSBR-044)State Key Laboratory of Mesoscience and Engineering,Institute of Process Engineering,Chinese Academy of Sciences(MESO-23-A06 and MESO-24-A01).
文摘Atomic surface engineering for nanostructures significantly contributes to the enhancement of electrocatalysis for a given chemical reaction.However,exploring a facile method to elaborately regulate surfaces at atomic scale remains a grand challenge.Herein,we report the construction of atomically rough surfaces(ARSs)on Au-based binary alloys through a novel and controllable gold(Au)-catalyzed strategy,which involves the first synthesis of Au-based bimetallic nanoalloys,i.e.,AuPd and AuAg,and subsequent reduction of another metal ions(Pt,Pd,or Ag)initiated by Au sites on the alloy particle surfaces.By combining ARSs with low-coordinated atoms with ligand effect induced by vicinal Au atoms,the as-prepared ARSs exhibit good activity and durability toward ethanol oxidation reaction(EOR)in an alkaline medium.In particular,the Pd-Pt ARSs on the AuPd alloy particle surface(denoted as AuPd-Pt)exhibit the highest electrocatalytic EOR performance in terms of both specific activity(14.9 mA cm^(–2))and mass activity(28.5 A mg^(–1)),surpassing those of their AuPd alloy counterparts,commercial Pd/C catalyst,and most Pd-based electrocatalysts reported recently.In situ Fourier transform infrared(FTIR)spectroscopy reveals that the EOR process on the Pd-Pt ARSs strongly prefers incomplete oxidation,which is further authenticated by the density functional theory(DFT)calculations.
基金supported by the National Natural Science Foundation of China(22309108,22202076,22272103)the China Postdoctoral Science Foundation(2022M711231,2023TQ0204)+3 种基金the Science and Technology Innovation Team of Shaanxi Province(2023-CX-TD27)the Fundamental Research Funds for the Central Universities(GK202202001)the 111 Project(B14041)Sanqin scholars'innovation teams in Shaanxi Province,China。
文摘The construction of bimetallic sites with strong interaction can effectively regulate the electronic structure and modulate the adsorption behavior of adsorbate species on bimetallic catalysts,thereby overcoming catalytic bottlenecks.Herein,an RhPb bimetallene(RhPb b-ML)with the strong d-p orbital hybridization is proposed for efficiently catalyzing ethanol oxidation reaction(EOR).Notably,the specific EOR activity of RhPb b-ML is 32 and 6.8 times higher than those of Rh metallene and commercial Pt/C,respectively.Theoretical calculation analysis reveals that the introduction of Pb atoms into the Rh lattice leads to an upward shift of the d-band center of Rh on RhPb(111).The shift in the d-band center is primarily attributed to the different degrees of hybridization between the d sub-orbitals of Rh and the p-orbitals of Pb,which enhance the adsorption of key species and improve EOR activity and selectivity.In-situ infrared tests and high-performance liquid chromatography tests together confirm that RhPb b-ML not only exhibits enhanced ability for the breakage of C-C bonds but also effectively suppresses the generation of absorbed CO.Furthermore,the strategy of enhancing catalyst performance through the strong d-p orbital hybridization has been demonstrated to be scalable to other bimetallic catalysts,providing valuable insights for the design of advanced catalysts.
基金the financial support from the National Natural Science Foundation of China(22197121)Knowledge Innovation Program of Wuhan-Basic Research(2022010801010202)Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202201)。
文摘Nucleophile oxidation reaction(NOR),represented by ethanol oxidation reaction(EOR),is a promising pathway to replace oxygen evolution reaction(OER).EOR can effectively reduce the driving voltage of hydrogen production in direct water splitting.In this work,large current and high efficiency of EOR on a Ni,Fe layered double hydroxide(NiFe-LDH)catalyst were simultaneously achieved by a facile fluorination strategy.F in NiFe-LDH can reduce the activation energy of the dehydrogenation reaction,thus promoting the deprotonation process of NiFe-LDH to achieve a lower EOR onset potential.It also weakens the absorption of OH-and nucleophile electrooxidation products on the surface of NiFe-LDH at a higher potential,achieving a high current density and EOR selectivity,according to density functional theory calculations.Based on our experiment results,the optimized fluorinated NiFe-LDH catalyst achieves a low potential of 1.386 V to deliver a 10 mA cm^(-2)EOR.Moreover,the Faraday efficiency is greater than 95%,with a current density ranging from 10 to 250 mA cm^(-2).This work provides a promising pathway for an efficient and cost-effective NOR catalyst design for economic hydrogen production.
基金the financial support provided by the National Natural Science Foundation of China(22075290,21972068,52164028)the Beijing Natural Science Foundation(Z200012)+3 种基金the State Key Laboratory of Multiphase Complex Systemsthe Institute of Process Engineeringthe Chinese Academy of Sciences(MPCS-2021-A-05)the Nanjing IPE Institute of Green Manufacturing Industry(E0010725).
文摘Dealloying by which the transition metal is partially or completely leached from an alloy precursor is an effective way to optimize the fundamental effects for further enhancing the electrocatalysis of a catalyst.Herein,to address the deficiencies associated with the commonly used dealloying methods,for example,electrochemical and sulfuric acid/nitric acid treatment,we report an acetic acid-assisted mild strategy to dealloy Cu atoms from the outer surface layers of CuPd alloy nanoparticles to achieve high-efficiency electrocatalysis for oxygen reduction and ethanol oxidation in an alkaline electrolyte.The leaching of Cu atoms by acetic acid exerts an additional compressive strain effect on the surface layers and exposes more active Pd atoms,which is beneficial for boosting the catalytic performance of a dealloyed catalyst for the oxygen reduction reaction(ORR)and the ethanol oxidation reaction(EOR).In particular,for ORR,the CuPd nanoparticles with a Pd/Cu molar ratio of 2:1 after acetic dealloying show a half-wave potential of 0.912 V(vs.RHE)and a mass activity of 0.213 AmgPd^(-1)at 0.9 V,respectively,while for EOR,the same dealloyed sample has a mass activity and a specific activity of 8.4 Amg^(-1)and 8.23 mA cm^(-2),respectively,much better than their dealloyed counterparts at other temperatures and commercial Pd/C as well as a Pt/C catalyst.
基金supported by the National Natural Science Foundation of China(Nos.22001143,21971132,and 52072197)Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)+5 种基金Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)Taishan Scholar Young Talent Program(Nos.tsqn201909114 and tsqn201909123)Natural Science Foundation of Shandong Province(Nos.ZR2020YQ34 and ZR2019MB042)Major Scientific and Technological Innovation Project(No.2019JZZY020405)Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09)the National Natural Science Foundation of China(No.22002083).
文摘The main problem faced by ethanol oxidation reaction(EOR)includes low activity,poor selectivity,and durability.In the study,we found that polysulfide modified on the surface of PtCu intermetallic(IM)/C can simultaneously enrich hydroxyl and ethanol,which could effectively improve the catalytic activity,CO_(2) selectivity,and durability of catalyst.The mass activity and the specific activity of the product in 1 M KOH electrolyte reached 17.83 A·mgPt^(-1) and 24.67 mA·cm^(-2).The CO_(2) selectivity of polysulfide modified product achieved 93.5%,which was 30 folds higher than Pt/C.In addition,the catalyst showed high catalytic stability.The mechanism study demonstrates that the surface modified polysulfide could significantly boost the enrichment effect of ethanol and hydroxyl species,accelerating C–C bond cleavage and CO oxidation.
基金supported by the National Natural Science Foundation of China(Nos.12025505,12105287,22002147,22179125,U21A20317,and 22373001)the National Key Research and Development Program of China(No.2021YFA1600800)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0450200)the Fundamental Research Funds for the Central Universities(No.KY2310000097)Xiaomi Young Talents Programsupported by the Supercomputing Center of the USTC.
文摘The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into electricity.Despite efforts,most Pt-based catalysts still suffer from drawbacks such as poor activity and susceptibility to CO poisoning,particularly in acidic conditions.Herein,we employed a physical laser-assisted approach to synthetize a PtPd alloy with a 1:1 atomic ratio.This alloy demonstrates remarkable performance in acidic EOR,boasting a high mass activity of 1.86 A·mgPt^(−1)and competitive resistance to poisoning.Combining in situ synchrotron radiation infrared spectroscopy with theoretical calculations,we reveal that the synergic interaction between Pt and Pd enhances both the adsorption of OH*intermediate and the dehydrogenation ability of ethanol.This work will prove the feasibility of synthesizing bimetallic alloys by a physical laser-assisted strategy and promote the development of advanced alloy electrocatalysts.
