Direct methanol fuel cells(DMFC) are widely considered to be an ideal green energy conversion device but their widespread applications are limited by the high price of the Pt-based catalysts and the instability in ter...Direct methanol fuel cells(DMFC) are widely considered to be an ideal green energy conversion device but their widespread applications are limited by the high price of the Pt-based catalysts and the instability in terms of surface CO toxicity in long-term operation.Herein,the PtFe alloy nanoparticles(NPs) with small particle size(~4.12 nm) supported on carbon black catalysts with different Pt/Fe atomic ratios(Pt_(1)Fe_(2)/C,Pt_(3)Fe_(4)/C,Pt_(1)Fe_(1)/C,and Pt_(2)Fe_(1)/C) are successfully prepared for enhanced anti-CO poisoning during methanol oxidation reaction(MOR).The optimal atomic ratio of Pt/Fe for the MOR is 1:2,and the mass activity of Pt_(1)Fe_(2)/C(5.40 A mg_(Pt)^(-1)) is 13.5 times higher than that of conventional commercial Pt/C(Pt/C-JM)(0.40 A mg_(Pt)^(-1)).The introduction of Fe into the Pt lattice forms the PtFe alloy phase,and the electron density of Pt is reduced after forming the PtFe alloy.In-situ Fourier transform infrared results indicate that the addition of oxyphilic metal Fe has reduced the adsorption of reactant molecules on Pt during the MOR.The doping of Fe atoms helps to desorb toxic intermediates and regenerate Pt active sites,promoting the cleavage of C-O bonds with good selectivity of CO_(2)(58.1%).Moreover,the Pt_(1)Fe_(2)/C catalyst exhibits higher CO tolerance,methanol electrooxidation activity,and long-term stability than other Pt_(x)Fe_(y)/C catalysts.展开更多
The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalyst...The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.展开更多
Platinum-based nanocomposites have been considered as one of the most promising catalysts for methanol oxidation reactions(MORs), which yet still suffer from low electrochemical activity and electron-transfer properti...Platinum-based nanocomposites have been considered as one of the most promising catalysts for methanol oxidation reactions(MORs), which yet still suffer from low electrochemical activity and electron-transfer properties. Apart from van-der-Waals heterostructures,herein, we report a novel nanocomposite with the structure of Pt–Ru bimetallic nanoparticles covalently-bonded onto multi-walled carbon nanotubes (MWCNTs)(Pt–Ru@MWCNT), which have been successfully fabricated via a facile and green synthesis method. It is demonstrated that the Pt–Ru@MWCNT nanocomposite possesses much enhanced electrocatalytic activity with the electrochemical active surface area(ECSA) of 110.4 m^(2)·g^(-1)for Pt towards MOR, which is 2.67 and 4.0 times higher than those of 20wt%commercial Pt@C and Pt-based nanocomposite prepared by other method, due to the improved electron-transfer properties originated from M–O–C covalent bonds. This work provides us a new strategy for the structural design of highly-efficient electrocatalysts in boosting MOR performance.展开更多
Direct methanol fuel cells are one of the most promising alternative energy technologies in the foreseeable future, but its successful commercialization in large scale is still heavily hindered by several technical sh...Direct methanol fuel cells are one of the most promising alternative energy technologies in the foreseeable future, but its successful commercialization in large scale is still heavily hindered by several technical shortfalls, especially the undesirable activity and durability issues of electrocatalysts toward methanol oxidation reaction. In light of these challenges, the inherent advantages of unsupported Pt based nanostructures demonstrate their great potentials as durable and efficient electrocatalysts for direct methanol fuel cells. This review will summarize recent achievements of unsupported Pt-based electrocatalysts toward methanol oxidation, with highlighting the interactions between the performance and structure tailoring and composition modulating. At last, a perspective is proposed for the upcoming challenges and possible opportunities to further prompt the practical application of unsupported Pt-based electrocatalysts for direct methanol fuel cells.展开更多
Pt/CeO_(2)-C catalysts with CeO_(2)pre-calcined at 300-600 ℃were synthesized by combining hydrothermal calcination and wet im-pregnation.The effects of the pre-calcined CeO_(2)on the performance of Pt/CeO_(2)-C catal...Pt/CeO_(2)-C catalysts with CeO_(2)pre-calcined at 300-600 ℃were synthesized by combining hydrothermal calcination and wet im-pregnation.The effects of the pre-calcined CeO_(2)on the performance of Pt/CeO_(2)-C catalysts in methanol oxidation were investigated.The Pt/CeO_(2)-C catalysts with pre-calcined CeO_(2)at 300-600 ℃showed an average particle size of 2.6-2.9 nm and exhibited better methanol elec-tro-oxidation catalytic activity than the commercial Pt/C catalyst.In specific,the Pt/CeO_(2)-C catalysts with pre-calcined CeO_(2)at 400 ℃dis-played the highest electrochemical surface area value of 68.14 m2·g−1 and If/Ib ratio(the ratio of the forward scanning peak current density(If)and the backward scanning peak current density(Ib))of 1.26,which are considerably larger than those(53.23 m2·g−1 and 0.79,respectively)of the commercial Pt/C catalyst,implying greatly enhanced CO tolerance.展开更多
Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination o...Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination of hollow structure,TiO2 shell and carbon layer results in excellent electron conductivity,electrocatalytic activity,and chemical stability.These uniformed DSCT hollow spheres are used as catalyst support to synthesize Pt/DSCT hollow spheres electrocatalyst.The resulting Pt/DSCT hollow spheres exhibited high catalytic performance with a current density of 462 mA mg^-1 for methanol oxidation reaction,which is 2.52 times higher than that of the commercial Pt/C.Furthermore,the increased tolerance to carbonaceous poisoning with a higher If/Ibratio and a better long-term stability in acid media suggests that the DSCT hollow sphere is a promising C/TiO2-based catalyst support for direct methanol fuel cells applications.展开更多
Although one-dimensional Pt nanocrystals have long been regarded as ideal electrode catalysts for fuel cells,the synthetic techniques commonly involve the use of various complicated templates or surfactants,which have...Although one-dimensional Pt nanocrystals have long been regarded as ideal electrode catalysts for fuel cells,the synthetic techniques commonly involve the use of various complicated templates or surfactants,which have largely hampered their large-scale industrial application.Herein,we present a convenient and cost-effective approach to the stereoassembly of quasi-one-dimensional grain boundary-enriched Pt nanoworms on nitrogen-doped low-defect graphitic carbon nanosheets(Pt NWs/NL-CNS).Benefiting from its numerous catalytically active grain boundaries as well as optimized electronic structure,the as-derived Pt NWs/NL-CNS catalyst possesses exceptionally good electrocatalytic properties for methanol oxidation,including an ultrahigh mass activity of 1949.5 mA mg^(-1), reliable long-term durability,and strong poison tolerance,affording one of the most active Pt-based electrocatalysts for methanol oxidation reaction.Density functional theory calculation further reveals that the formation of worm-shape Pt morphology is attributed to the modified electronic structure as well as controllable defect density of the carbon matrix,which could also weaken the adsorption ability of Pt towards CO molecule and meanwhile synergistically promotes the catalytic reaction kinetics.展开更多
Platinum catalysts play a major role in the large scale commercialization of direct methanol fuel cells(DMFC).Here,we present a procedure to create a nanostructural graphene-platinum(Gr Pt)composite containing a small...Platinum catalysts play a major role in the large scale commercialization of direct methanol fuel cells(DMFC).Here,we present a procedure to create a nanostructural graphene-platinum(Gr Pt)composite containing a small amount(5.3 wt%)of platinum nanoparticles coated with at least four layers of graphene.The composite,as Gr Pt ink,was deposited on a glassy carbon electrode and its electrocatalytic activity in a methanol oxidation reaction(MOR)was evaluated in a 1 M CH3OH/1 M NaOH solution.The results indicated an enhanced catalytic performance of GrPt towards MOR in alkaline media compared with the Pt/C material.Electron energy-loss spectroscopy and X-ray photoelectron spectroscopy(recorded before and after the electrochemical assays)were employed to analyze the changes in the chemical composition of the nanomaterial and to explain the transformations that took place at the electrode surface.Our findings suggest that growing of graphene on platinum nanoparticles improve the catalytic performance of platinum-graphene composites towards MOR in alkaline media.展开更多
Exploring effective, durable, and affordable electrocatalysts of methanol oxidation reaction(MOR) is of vital significance for the industrial application of direct methanol fuel cells. Herein, an efficient, general,an...Exploring effective, durable, and affordable electrocatalysts of methanol oxidation reaction(MOR) is of vital significance for the industrial application of direct methanol fuel cells. Herein, an efficient, general,and expandable method is developed to synthesis two-dimensional(2D) ternary Pt Bi M nanoplates(NPLs), in which various M(Co, Ni, Cu, Zn, Sn) is severed as the third component to the binary Pt Bi system. The MOR performance of Pt Bi M NPLs is entirely investigated, demonstrating that both the MOR activity and durability is enhanced with the introduction of the additional composition. Pt3Bi3Zn NPLs shows much higher MOR activity and stability than that of the Pt Bi counterparts, not to mention the current advanced Pt Ru/C and Pt/C catalysts. The prominent performances are attributed to the modulated electronic structure of the surface Pt in Pt Bi NPLs by the addition of Zn, resulting in a weakened affination between Pt and the adsorbed poisoning species(mainly CO) compared with Pt Bi NPLs, verified by density functional theory(DFT) calculations. In addition, the absorbed OH can be generated on the surface of Zn atom due to its favorable water activation properties, thus the CO removal on the adjacent Pt atoms is accelerated, further leading to a high activity and anti-poisoning performance of the resulting Pt_(3)Bi_(3)Zn catalyst. This work provides new insights and robust strategy for highly efficient MOR electrocatalyst with extraordinary anti-poisoning performance and stability.展开更多
Noble metal-based electrocatalysts present high activities for methanol oxidation reaction(MOR),but are limited by their high cost,low stability and poor resistance to carbon monoxide(CO) poisoning.The development of ...Noble metal-based electrocatalysts present high activities for methanol oxidation reaction(MOR),but are limited by their high cost,low stability and poor resistance to carbon monoxide(CO) poisoning.The development of active and stable non-noble metal electrocatalysts for MOR is desired,but remains a challenge.Herein,we report a simple strategy to make copper nanocrystal/nitrogen-doped carbon(Cu/N-C)monoliths,which can serve as active and robust electrodes for MOR.Copper nanocrystals were electrochemically deposited onto a conductive polyaniline hydrogel and calcined to form Cu/N-C monolith,where the active copper nanocrystals are protected by nitrogen-doped carbon.Owing to their extremely high electrical conductivity(1.25 × 10^(5) S cm^(-1)) and mechanical robustness,these Cu/N-C monoliths can be directly used as electrodes for MOR,without using substrates or additives.The optimal Cu/N-C(FT)@500 monolith shows a high MOR activity of 189 mA cm^(-2) at 0.6 V vs.SCE in alkaline methanol solution,superior to most of reported Cu-based MOR catalysts.Cu/N-C(FT)@500 also presents a better stability than Pt/C catalyst in the long-term MOR test at high current densities.Upon carbon monoxide(CO) poisoning,Cu/N-C(FT)@500 retains 96% of its MOR activity,far exceeding the performance of Pt/C catalyst(61% retention).Owing to its facile synthesis,outstanding activity,high stability and mechanical robustness,Cu/N-C(FT)@500 monolith is promising as a low-cost,efficient and CO-resistant electrocatalyst for MOR.展开更多
Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants.Here,we developed a simple aqueous synthetic method...Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants.Here,we developed a simple aqueous synthetic method to prepare bimetallic PdAu nanoflowers catalysts for methanol oxidation reaction(MOR)in alkaline environment.Their composition can be directly tuned by changing the ratio between Pd and Au precursors.Compared with commercial Pd/C catalyst,all of the PdAu nanoflowers catalysts show the enhanced catalytic activity and durability.In particular,the PdAu nanoflowers specific activity reached 0.72 mA/cm^(2),which is 14 times that of commercial Pd/C catalyst.The superior MOR activity could be attributed to the unique porous structure and the shift of the d-band center of Pd.展开更多
The electrochemical methanol oxidation reaction(MOR) is of paramount importance for direct methanol fuel cell(DMFC) application, where efficient catalysts are required to facilitate the complicated multiple charge tra...The electrochemical methanol oxidation reaction(MOR) is of paramount importance for direct methanol fuel cell(DMFC) application, where efficient catalysts are required to facilitate the complicated multiple charge transfer process. The catalyst support not only determines the dispersion status of the catalysts particles, but also exerts great influence on the electronic structure of the catalysts, thereby altering its intrinsic activity. Herein, we demonstrated that nitrogen atoms, assisted by the pre-treatment of carbon matrix with oxidants, can be easily doped into carbon nanotubes at low temperature. The obtained nitrogen-doped carbon nanotubes can effectively improve the dispersion of the supported platinum nanoparticles and facilitate the MOR by modifying the electronic structure of platinum atoms,through catalyst-support interaction.展开更多
The research on electrocatalysts with relatively lower price than Pt and excellent electrocatalytic performance for the cathode oxygen reduction reaction(ORR) and anode methanol oxidation reaction(MOR) is vital for th...The research on electrocatalysts with relatively lower price than Pt and excellent electrocatalytic performance for the cathode oxygen reduction reaction(ORR) and anode methanol oxidation reaction(MOR) is vital for the development of direct methanol fuel cells(DMFCs). In this work, we develop a cyanogel-reduction method to synthesize reduced graphene oxide(rGO) supported highly dispersed PdNi alloy nanocrystals(PdNi/rGO) with high alloying degree and tunable Pd/Ni ratio. The large specific surface area and the d-band center downshift of Pd result in excellent activity of Pd4 Ni1/rGO nanohybrids for the ORR. The modification of Pd electronic structure can facilitate the adsorption of CH3 OH on Pd surface and the highly oxophilic property of Ni can eliminate/mitigate the COadsintermediates poisoning, which make PdNi/r GO nanohybrids possess superior MOR activity. In addition, rGO improve the stability of PdNi alloy nanocrystals for the ORR and MOR. Due to high activity and stability for the ORR and MOR, PdNi/rGO nanohybrids are promising to be an available bifunctional electrocatalyst in DMFCs.展开更多
PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing ...PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction( XRD),energy dispersive analysis( EDX),transmission electron microscopy( TEM),cyclic voltammetry( CV),chronoamperommetry( CA) and polarization curves in alkaline and acidic electrolytes( single cell experiments). The XRD patterns showPtpeaks are attributed to the face-centered cubic( fcc) structure,and a shift of Pt( fcc) peaks indicates that Ru or In is incorporated into Ptlattice. TEMmicrographs showmetal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. Methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature,by CV and CA. PtRu/C( 50 ∶ 50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80 ℃ showPtRuIn/C( 50 ∶ 25 ∶ 25)with superior performance for methanol oxidation,when compared to Pt/C,PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C( 50 ∶ 25 ∶ 25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Ptalloy.展开更多
In this work,fullerene was modified by platinum,ruthenium,tin and tungsten nanoparticles.The material was characterized by XRD,ICP-OES and TEM micrograph.The average nanoparticle size on fullerene was 5-8 nm.The appli...In this work,fullerene was modified by platinum,ruthenium,tin and tungsten nanoparticles.The material was characterized by XRD,ICP-OES and TEM micrograph.The average nanoparticle size on fullerene was 5-8 nm.The application of this material was investigated as a catalyst for methanol oxidation in direct methanol fuel cell.A glassy carbon electrode was modified by Pt/Ru/Sn/W fullerene and electrocatalytic activity of the electrode toward methanol oxidation in basic medium has been demonstrated and investigated using cyclic voltammetry.The catalyst showed good reactivity for methanol oxidation.展开更多
Up to this date,researchers are still facing difficulties to expand the technology of direct methanol fuel cells(DMFCs) because of the high overpotential required to oxidize the methanol and its relatively poor perfor...Up to this date,researchers are still facing difficulties to expand the technology of direct methanol fuel cells(DMFCs) because of the high overpotential required to oxidize the methanol and its relatively poor performance due to CO poisoning of the leading-high cost anode catalyst.In line with this,we have successfully modified the morphological structure and composition of low cost cobalt based-metal oxides,MCo_2O_4(M = Zn and Ni),with the simple and noble use of polyvinyl pyrrolidone(PVP) as growth modifier and surface stabilizer during the synthesis of nanoparticles in our previous reports,which shown high electrocatalytic activity and strong stability.Due to the good performance of our PVP modified MCo_2O_4 towards pseudocapacitor and oxygen evolution reaction applications,we decided to extend our research study to methanol oxidation reaction.Remarkably,PVP modified Ni Co_2O_4 electrode directly grown on nickel foam substrate via a simple hydrothermal process exhibited better performance compared with PVP modified ZnCo_2O_4 and NiCo_2O_4 without PVP.It had obtained a remarkably low onset potential of 0.285 V and high current density of 280 m A cm^(-2),and shown great stability and high poison tolerance during a continuous CV cycling and Chronoamperometry test,which attained high efficiency of 86.86%and 98.52%,respectively.These positive results of PVP modified Ni Co_2O_4 electrode towards MOR might be attributed to its hierarchical 3 D nanostructures with highly mesoporous surface and large surface area which may have provided numerous electroactive sites,and the exceptional corrosion stability of Ni Co_2O_4 electrode in alkaline solution.展开更多
Au@Pt core-shell nanoparticles were successfully synthesized by a successive reduction method and then assembled on Vulcan XC-72 carbon surface.Furthermore,its composition,morphology,structure,and activity towards met...Au@Pt core-shell nanoparticles were successfully synthesized by a successive reduction method and then assembled on Vulcan XC-72 carbon surface.Furthermore,its composition,morphology,structure,and activity towards methanol oxidation were characterized by UV-vis spectrometry,transmission electron microscopy (TEM),high-resolution TEM (HRTEM),X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),and cyclic voltammetry (CV).Results reveal that Au@Pt/C catalyst has better activity towards methanol oxidation than the pure platinum prepared under the same conditions.When the atomic ratio of Au to Pt in the prepared Au@Pt/C catalyst is 1∶2,this catalyst exhibits best electrocatalytic activity towards methanol oxidation in acidic media,and the peak current density on this catalyst is ～2.0times higher than that on Pt/C catalyst.The better catalytic activity of Au@Pt/C results from its better resistance to toxic CO than Pt/C because the CO oxidation on Au@Pt/C is 60 mV more negative than the case on Pt/C.展开更多
In order to develop a novel and high-performance catalytic material for direct methanol fuel cells(DMFC), molybdenum oxide as a co-catalyst with Pt on multi-walled carbon nanotubes which were modified by titanium dio-...In order to develop a novel and high-performance catalytic material for direct methanol fuel cells(DMFC), molybdenum oxide as a co-catalyst with Pt on multi-walled carbon nanotubes which were modified by titanium dio-xide(denoted as CNTs@TiO2) was investigated. The physicochemical characterizations of the catalysts were carried out via X-ray diffraction(XRD), transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS). Cyclic voltammetry(CV) showed that the CO-tolerance performance increased in the sequence of Pt/CNTs< Pt/CNTs@TiO2<Pt-Mo/CNTs@TiO2. The improved CO-tolerance performance of the Pt-Mo/CNTs@TiO2 catalyst can be attributed to the combined beneficial effects of highly dispersed Pt nanoparticles on the CNTs, the existence of oxygen holes in the MoO3 layer structure and the oxidation capability of TiO2.展开更多
A novel method to prepare an electrocatalyst with a new structure and high catalytic performance was reported. Two-dimensional(2 D) PtRu nanoclusters have been successfully deposited on graphene oxide and carbon black...A novel method to prepare an electrocatalyst with a new structure and high catalytic performance was reported. Two-dimensional(2 D) PtRu nanoclusters have been successfully deposited on graphene oxide and carbon black supports. Compared with the commercial 3 D E-TEK PtRu samples, the prepared 2 D PtRu composites have larger electrochemically active surface area and display much higher catalytic activity toward methanol oxidation reaction. The preparation method mainly includes the following procedures: oxidation of carbon matrix, Pb^(2+) adsorption on the surface of carbon support, Pb^(2+) electrochemical reduction and galvanic displacement of Pb^0 by Pt^(2+) and Ru^(3+). The method developed in this study could be viable for solving the problem of low electrocatalytic activity in direct methanol fuel cell anodes.展开更多
基金supported by the National Natural Science Foundation of China(22162012 and 22202089)the Youth Jinggang Scholars Program in Jiangxi Province([2019]57)+6 种基金the Thousand Talents Plan of Jiangxi Province(jxsq2019201083)the Natural Science Foundation of Jiangxi Province for Distinguished Young Scholars(20224ACB213005)the Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology(JXUSTQJBJ2019002)the Research Foundation of Education Bureau of Jiangxi Province of China(GJJ210833)the Foundation of State Key Laboratory of Physical Chemistry of Solid Surfaces(202022)the China Postdoctoral Science Foundation(2021M693893)the Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry(20212BCD42018)。
文摘Direct methanol fuel cells(DMFC) are widely considered to be an ideal green energy conversion device but their widespread applications are limited by the high price of the Pt-based catalysts and the instability in terms of surface CO toxicity in long-term operation.Herein,the PtFe alloy nanoparticles(NPs) with small particle size(~4.12 nm) supported on carbon black catalysts with different Pt/Fe atomic ratios(Pt_(1)Fe_(2)/C,Pt_(3)Fe_(4)/C,Pt_(1)Fe_(1)/C,and Pt_(2)Fe_(1)/C) are successfully prepared for enhanced anti-CO poisoning during methanol oxidation reaction(MOR).The optimal atomic ratio of Pt/Fe for the MOR is 1:2,and the mass activity of Pt_(1)Fe_(2)/C(5.40 A mg_(Pt)^(-1)) is 13.5 times higher than that of conventional commercial Pt/C(Pt/C-JM)(0.40 A mg_(Pt)^(-1)).The introduction of Fe into the Pt lattice forms the PtFe alloy phase,and the electron density of Pt is reduced after forming the PtFe alloy.In-situ Fourier transform infrared results indicate that the addition of oxyphilic metal Fe has reduced the adsorption of reactant molecules on Pt during the MOR.The doping of Fe atoms helps to desorb toxic intermediates and regenerate Pt active sites,promoting the cleavage of C-O bonds with good selectivity of CO_(2)(58.1%).Moreover,the Pt_(1)Fe_(2)/C catalyst exhibits higher CO tolerance,methanol electrooxidation activity,and long-term stability than other Pt_(x)Fe_(y)/C catalysts.
基金financially supported by the National Natural Science Foundation of China (52200076,22169005,52370057)the Growth Project of Young Scientific and Technological Talents in General Colleges and Universities in Guizhou Province ([2022]143)+4 种基金the Science and Technology Foundation of Guizhou Province ([2022]109)the Natural Science Special Foundation of Guizhou University (202017,702775203301)the Natural Science Foundation of Chongqing (CSTB2022NSCQ-BHX0035)the Special Research Assistant Program of Chinese Academy of Sciencethe Research Foundation of Chongqing University of Science and Technology (ckrc2022026)。
文摘The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.
基金the support from Shanghai QingZhen Test Technology Co.,Ltd.,China (No.880772)Dalian Jin Dian Biotechnology Co.,Ltd.,China (No.880988)+5 种基金Anhui Chromatographic Instrument Co.,Ltd.,China (No.880511)the Key Project of Anhui Provincial Department of Education,China (No.2023AH051634)the Innovative Research Team of Undergraduates,China (Nos.S202110879087 and S202210879085)the Research Funds of Anhui Science and Technology University,China (No.FZ220179)the Foundation of Anhui Science and Technology University,China (No.HCWD202001)the Science and Technology Planning Project of Bengbu City,China (No.2022gx10)。
文摘Platinum-based nanocomposites have been considered as one of the most promising catalysts for methanol oxidation reactions(MORs), which yet still suffer from low electrochemical activity and electron-transfer properties. Apart from van-der-Waals heterostructures,herein, we report a novel nanocomposite with the structure of Pt–Ru bimetallic nanoparticles covalently-bonded onto multi-walled carbon nanotubes (MWCNTs)(Pt–Ru@MWCNT), which have been successfully fabricated via a facile and green synthesis method. It is demonstrated that the Pt–Ru@MWCNT nanocomposite possesses much enhanced electrocatalytic activity with the electrochemical active surface area(ECSA) of 110.4 m^(2)·g^(-1)for Pt towards MOR, which is 2.67 and 4.0 times higher than those of 20wt%commercial Pt@C and Pt-based nanocomposite prepared by other method, due to the improved electron-transfer properties originated from M–O–C covalent bonds. This work provides us a new strategy for the structural design of highly-efficient electrocatalysts in boosting MOR performance.
基金financial supported by National 1000 Young Talents Program of ChinaNation Natural Science Foundation of China(21473111)+2 种基金The Innovation Foundation of Shenzhen Government(JCYJ20160408173202143)the Joint Fund of Energy Storage of Qingdao(20160012)the Innovation Research Funds of HUST(3004013109,0118013089,and 2017KFYXJJ164)
文摘Direct methanol fuel cells are one of the most promising alternative energy technologies in the foreseeable future, but its successful commercialization in large scale is still heavily hindered by several technical shortfalls, especially the undesirable activity and durability issues of electrocatalysts toward methanol oxidation reaction. In light of these challenges, the inherent advantages of unsupported Pt based nanostructures demonstrate their great potentials as durable and efficient electrocatalysts for direct methanol fuel cells. This review will summarize recent achievements of unsupported Pt-based electrocatalysts toward methanol oxidation, with highlighting the interactions between the performance and structure tailoring and composition modulating. At last, a perspective is proposed for the upcoming challenges and possible opportunities to further prompt the practical application of unsupported Pt-based electrocatalysts for direct methanol fuel cells.
基金This work was financially supported by the National Nat-ural Science Foundation of China(No.51774145).
文摘Pt/CeO_(2)-C catalysts with CeO_(2)pre-calcined at 300-600 ℃were synthesized by combining hydrothermal calcination and wet im-pregnation.The effects of the pre-calcined CeO_(2)on the performance of Pt/CeO_(2)-C catalysts in methanol oxidation were investigated.The Pt/CeO_(2)-C catalysts with pre-calcined CeO_(2)at 300-600 ℃showed an average particle size of 2.6-2.9 nm and exhibited better methanol elec-tro-oxidation catalytic activity than the commercial Pt/C catalyst.In specific,the Pt/CeO_(2)-C catalysts with pre-calcined CeO_(2)at 400 ℃dis-played the highest electrochemical surface area value of 68.14 m2·g−1 and If/Ib ratio(the ratio of the forward scanning peak current density(If)and the backward scanning peak current density(Ib))of 1.26,which are considerably larger than those(53.23 m2·g−1 and 0.79,respectively)of the commercial Pt/C catalyst,implying greatly enhanced CO tolerance.
基金supported by the Scholarship from China Scholarship Council(CSC)(Grant no.201604910621)。
文摘Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination of hollow structure,TiO2 shell and carbon layer results in excellent electron conductivity,electrocatalytic activity,and chemical stability.These uniformed DSCT hollow spheres are used as catalyst support to synthesize Pt/DSCT hollow spheres electrocatalyst.The resulting Pt/DSCT hollow spheres exhibited high catalytic performance with a current density of 462 mA mg^-1 for methanol oxidation reaction,which is 2.52 times higher than that of the commercial Pt/C.Furthermore,the increased tolerance to carbonaceous poisoning with a higher If/Ibratio and a better long-term stability in acid media suggests that the DSCT hollow sphere is a promising C/TiO2-based catalyst support for direct methanol fuel cells applications.
基金financially supported by the National Natural Science Foundation of China(51802077,21975129)the Fundamental Research Funds for the Central Universities(2019B16214)+1 种基金China Postdoctoral Science Foundation(2016 T90414)Jiangsu Planned Projects for Postdoctoral Research Funds(1601026A)。
文摘Although one-dimensional Pt nanocrystals have long been regarded as ideal electrode catalysts for fuel cells,the synthetic techniques commonly involve the use of various complicated templates or surfactants,which have largely hampered their large-scale industrial application.Herein,we present a convenient and cost-effective approach to the stereoassembly of quasi-one-dimensional grain boundary-enriched Pt nanoworms on nitrogen-doped low-defect graphitic carbon nanosheets(Pt NWs/NL-CNS).Benefiting from its numerous catalytically active grain boundaries as well as optimized electronic structure,the as-derived Pt NWs/NL-CNS catalyst possesses exceptionally good electrocatalytic properties for methanol oxidation,including an ultrahigh mass activity of 1949.5 mA mg^(-1), reliable long-term durability,and strong poison tolerance,affording one of the most active Pt-based electrocatalysts for methanol oxidation reaction.Density functional theory calculation further reveals that the formation of worm-shape Pt morphology is attributed to the modified electronic structure as well as controllable defect density of the carbon matrix,which could also weaken the adsorption ability of Pt towards CO molecule and meanwhile synergistically promotes the catalytic reaction kinetics.
基金financially supported by Romanian National Authority for Scientific Research and Innovation (ANCSI) by NUCLEU Program PN 18 03 02 02
文摘Platinum catalysts play a major role in the large scale commercialization of direct methanol fuel cells(DMFC).Here,we present a procedure to create a nanostructural graphene-platinum(Gr Pt)composite containing a small amount(5.3 wt%)of platinum nanoparticles coated with at least four layers of graphene.The composite,as Gr Pt ink,was deposited on a glassy carbon electrode and its electrocatalytic activity in a methanol oxidation reaction(MOR)was evaluated in a 1 M CH3OH/1 M NaOH solution.The results indicated an enhanced catalytic performance of GrPt towards MOR in alkaline media compared with the Pt/C material.Electron energy-loss spectroscopy and X-ray photoelectron spectroscopy(recorded before and after the electrochemical assays)were employed to analyze the changes in the chemical composition of the nanomaterial and to explain the transformations that took place at the electrode surface.Our findings suggest that growing of graphene on platinum nanoparticles improve the catalytic performance of platinum-graphene composites towards MOR in alkaline media.
基金supported by the Hainan Province Science and Technology Special Fund(ZDYF2020037,2020207)the National Natural Science Foundation of China(21805104,22109034,22109035,52164028,62105083)+3 种基金the Basic and Applied Basic Research Foundation of Guangdong Province(2019A1515110558)the Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province(202021)the Innovative Research Projects for Graduate Students of Hainan Province(Qhys2021-134)the Start-up Research Foundation of Hainan University(KYQD(ZR)-20008,20082,20083,20084,21065,21124,21125)。
文摘Exploring effective, durable, and affordable electrocatalysts of methanol oxidation reaction(MOR) is of vital significance for the industrial application of direct methanol fuel cells. Herein, an efficient, general,and expandable method is developed to synthesis two-dimensional(2D) ternary Pt Bi M nanoplates(NPLs), in which various M(Co, Ni, Cu, Zn, Sn) is severed as the third component to the binary Pt Bi system. The MOR performance of Pt Bi M NPLs is entirely investigated, demonstrating that both the MOR activity and durability is enhanced with the introduction of the additional composition. Pt3Bi3Zn NPLs shows much higher MOR activity and stability than that of the Pt Bi counterparts, not to mention the current advanced Pt Ru/C and Pt/C catalysts. The prominent performances are attributed to the modulated electronic structure of the surface Pt in Pt Bi NPLs by the addition of Zn, resulting in a weakened affination between Pt and the adsorbed poisoning species(mainly CO) compared with Pt Bi NPLs, verified by density functional theory(DFT) calculations. In addition, the absorbed OH can be generated on the surface of Zn atom due to its favorable water activation properties, thus the CO removal on the adjacent Pt atoms is accelerated, further leading to a high activity and anti-poisoning performance of the resulting Pt_(3)Bi_(3)Zn catalyst. This work provides new insights and robust strategy for highly efficient MOR electrocatalyst with extraordinary anti-poisoning performance and stability.
基金supported by the National Natural Science Foundation of China(21722406,21975240,21676258)by the Fundamental Research Funds for the Central Universities(WK2060190102)+1 种基金by the Central Leading Local Science and Technology Development Special Fund Project(YDZX20191400002636)by the Scientific and Technologial Innovation Programs of Higher Education Institutions in Shanxi(STIP 2020L0695)。
文摘Noble metal-based electrocatalysts present high activities for methanol oxidation reaction(MOR),but are limited by their high cost,low stability and poor resistance to carbon monoxide(CO) poisoning.The development of active and stable non-noble metal electrocatalysts for MOR is desired,but remains a challenge.Herein,we report a simple strategy to make copper nanocrystal/nitrogen-doped carbon(Cu/N-C)monoliths,which can serve as active and robust electrodes for MOR.Copper nanocrystals were electrochemically deposited onto a conductive polyaniline hydrogel and calcined to form Cu/N-C monolith,where the active copper nanocrystals are protected by nitrogen-doped carbon.Owing to their extremely high electrical conductivity(1.25 × 10^(5) S cm^(-1)) and mechanical robustness,these Cu/N-C monoliths can be directly used as electrodes for MOR,without using substrates or additives.The optimal Cu/N-C(FT)@500 monolith shows a high MOR activity of 189 mA cm^(-2) at 0.6 V vs.SCE in alkaline methanol solution,superior to most of reported Cu-based MOR catalysts.Cu/N-C(FT)@500 also presents a better stability than Pt/C catalyst in the long-term MOR test at high current densities.Upon carbon monoxide(CO) poisoning,Cu/N-C(FT)@500 retains 96% of its MOR activity,far exceeding the performance of Pt/C catalyst(61% retention).Owing to its facile synthesis,outstanding activity,high stability and mechanical robustness,Cu/N-C(FT)@500 monolith is promising as a low-cost,efficient and CO-resistant electrocatalyst for MOR.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.118740271 and 1774124)Technology Development Program of Jilin Province,China(Grant No.20180101285JC)the China Postdoctoral Science Foundation(Grant Nos.2019T120233 and 2017M621198)
文摘Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants.Here,we developed a simple aqueous synthetic method to prepare bimetallic PdAu nanoflowers catalysts for methanol oxidation reaction(MOR)in alkaline environment.Their composition can be directly tuned by changing the ratio between Pd and Au precursors.Compared with commercial Pd/C catalyst,all of the PdAu nanoflowers catalysts show the enhanced catalytic activity and durability.In particular,the PdAu nanoflowers specific activity reached 0.72 mA/cm^(2),which is 14 times that of commercial Pd/C catalyst.The superior MOR activity could be attributed to the unique porous structure and the shift of the d-band center of Pd.
基金supported by the National Natural Science Foundation of China (21433003, 21633008)the Jilin Province Science and Technology Development Program (20150101066JC, 20160622037JC, 20170203003SF, and 20170520150JH)the Hundred Talents Program of the Chinese Academy of Sciences and the Recruitment Program of Foreign Experts (WQ20122200077)
文摘The electrochemical methanol oxidation reaction(MOR) is of paramount importance for direct methanol fuel cell(DMFC) application, where efficient catalysts are required to facilitate the complicated multiple charge transfer process. The catalyst support not only determines the dispersion status of the catalysts particles, but also exerts great influence on the electronic structure of the catalysts, thereby altering its intrinsic activity. Herein, we demonstrated that nitrogen atoms, assisted by the pre-treatment of carbon matrix with oxidants, can be easily doped into carbon nanotubes at low temperature. The obtained nitrogen-doped carbon nanotubes can effectively improve the dispersion of the supported platinum nanoparticles and facilitate the MOR by modifying the electronic structure of platinum atoms,through catalyst-support interaction.
基金the National Natural Science Foundation of China (21473111)the Fundamental Research Funds for the Central Universities (GK201701007)
文摘The research on electrocatalysts with relatively lower price than Pt and excellent electrocatalytic performance for the cathode oxygen reduction reaction(ORR) and anode methanol oxidation reaction(MOR) is vital for the development of direct methanol fuel cells(DMFCs). In this work, we develop a cyanogel-reduction method to synthesize reduced graphene oxide(rGO) supported highly dispersed PdNi alloy nanocrystals(PdNi/rGO) with high alloying degree and tunable Pd/Ni ratio. The large specific surface area and the d-band center downshift of Pd result in excellent activity of Pd4 Ni1/rGO nanohybrids for the ORR. The modification of Pd electronic structure can facilitate the adsorption of CH3 OH on Pd surface and the highly oxophilic property of Ni can eliminate/mitigate the COadsintermediates poisoning, which make PdNi/r GO nanohybrids possess superior MOR activity. In addition, rGO improve the stability of PdNi alloy nanocrystals for the ORR and MOR. Due to high activity and stability for the ORR and MOR, PdNi/rGO nanohybrids are promising to be an available bifunctional electrocatalyst in DMFCs.
文摘PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction( XRD),energy dispersive analysis( EDX),transmission electron microscopy( TEM),cyclic voltammetry( CV),chronoamperommetry( CA) and polarization curves in alkaline and acidic electrolytes( single cell experiments). The XRD patterns showPtpeaks are attributed to the face-centered cubic( fcc) structure,and a shift of Pt( fcc) peaks indicates that Ru or In is incorporated into Ptlattice. TEMmicrographs showmetal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. Methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature,by CV and CA. PtRu/C( 50 ∶ 50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80 ℃ showPtRuIn/C( 50 ∶ 25 ∶ 25)with superior performance for methanol oxidation,when compared to Pt/C,PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C( 50 ∶ 25 ∶ 25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Ptalloy.
基金Financial support from Renewable Energy Organization of Iran(SUNA)
文摘In this work,fullerene was modified by platinum,ruthenium,tin and tungsten nanoparticles.The material was characterized by XRD,ICP-OES and TEM micrograph.The average nanoparticle size on fullerene was 5-8 nm.The application of this material was investigated as a catalyst for methanol oxidation in direct methanol fuel cell.A glassy carbon electrode was modified by Pt/Ru/Sn/W fullerene and electrocatalytic activity of the electrode toward methanol oxidation in basic medium has been demonstrated and investigated using cyclic voltammetry.The catalyst showed good reactivity for methanol oxidation.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) - Grants funded by the Ministry of Trade,Industry and Energy (MOTIE) (No.20174010201160)the National Research Foundation of Korea (NRF) - Grant funded by the Ministry of Education (No.20090093816),Republic of Korea
文摘Up to this date,researchers are still facing difficulties to expand the technology of direct methanol fuel cells(DMFCs) because of the high overpotential required to oxidize the methanol and its relatively poor performance due to CO poisoning of the leading-high cost anode catalyst.In line with this,we have successfully modified the morphological structure and composition of low cost cobalt based-metal oxides,MCo_2O_4(M = Zn and Ni),with the simple and noble use of polyvinyl pyrrolidone(PVP) as growth modifier and surface stabilizer during the synthesis of nanoparticles in our previous reports,which shown high electrocatalytic activity and strong stability.Due to the good performance of our PVP modified MCo_2O_4 towards pseudocapacitor and oxygen evolution reaction applications,we decided to extend our research study to methanol oxidation reaction.Remarkably,PVP modified Ni Co_2O_4 electrode directly grown on nickel foam substrate via a simple hydrothermal process exhibited better performance compared with PVP modified ZnCo_2O_4 and NiCo_2O_4 without PVP.It had obtained a remarkably low onset potential of 0.285 V and high current density of 280 m A cm^(-2),and shown great stability and high poison tolerance during a continuous CV cycling and Chronoamperometry test,which attained high efficiency of 86.86%and 98.52%,respectively.These positive results of PVP modified Ni Co_2O_4 electrode towards MOR might be attributed to its hierarchical 3 D nanostructures with highly mesoporous surface and large surface area which may have provided numerous electroactive sites,and the exceptional corrosion stability of Ni Co_2O_4 electrode in alkaline solution.
基金ACKNOWLEDGEMENTS This work was supported by the National Natural Science Foundation of China （No.21273215）, National Instrumentation Program （No.2011YQ03012416）, and 973 Program from the Ministry of Science and Technology of China （No.2010CB923302）.
基金supported financially by the National Natural Science Foundation of China (No.51074012)
文摘Au@Pt core-shell nanoparticles were successfully synthesized by a successive reduction method and then assembled on Vulcan XC-72 carbon surface.Furthermore,its composition,morphology,structure,and activity towards methanol oxidation were characterized by UV-vis spectrometry,transmission electron microscopy (TEM),high-resolution TEM (HRTEM),X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),and cyclic voltammetry (CV).Results reveal that Au@Pt/C catalyst has better activity towards methanol oxidation than the pure platinum prepared under the same conditions.When the atomic ratio of Au to Pt in the prepared Au@Pt/C catalyst is 1∶2,this catalyst exhibits best electrocatalytic activity towards methanol oxidation in acidic media,and the peak current density on this catalyst is ～2.0times higher than that on Pt/C catalyst.The better catalytic activity of Au@Pt/C results from its better resistance to toxic CO than Pt/C because the CO oxidation on Au@Pt/C is 60 mV more negative than the case on Pt/C.
基金Supported by the National Natural Science Foundation of China(No.20636060)International Science and Technology Cooperation Program of China(No.2006DFA61240)
文摘In order to develop a novel and high-performance catalytic material for direct methanol fuel cells(DMFC), molybdenum oxide as a co-catalyst with Pt on multi-walled carbon nanotubes which were modified by titanium dio-xide(denoted as CNTs@TiO2) was investigated. The physicochemical characterizations of the catalysts were carried out via X-ray diffraction(XRD), transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS). Cyclic voltammetry(CV) showed that the CO-tolerance performance increased in the sequence of Pt/CNTs< Pt/CNTs@TiO2<Pt-Mo/CNTs@TiO2. The improved CO-tolerance performance of the Pt-Mo/CNTs@TiO2 catalyst can be attributed to the combined beneficial effects of highly dispersed Pt nanoparticles on the CNTs, the existence of oxygen holes in the MoO3 layer structure and the oxidation capability of TiO2.
基金Funded by National Natural Science Foundation of China(Nos.21376069 and 21576075)Key Project in Hunan Science and Technology Pillar Program(No.2015WK3020)
文摘A novel method to prepare an electrocatalyst with a new structure and high catalytic performance was reported. Two-dimensional(2 D) PtRu nanoclusters have been successfully deposited on graphene oxide and carbon black supports. Compared with the commercial 3 D E-TEK PtRu samples, the prepared 2 D PtRu composites have larger electrochemically active surface area and display much higher catalytic activity toward methanol oxidation reaction. The preparation method mainly includes the following procedures: oxidation of carbon matrix, Pb^(2+) adsorption on the surface of carbon support, Pb^(2+) electrochemical reduction and galvanic displacement of Pb^0 by Pt^(2+) and Ru^(3+). The method developed in this study could be viable for solving the problem of low electrocatalytic activity in direct methanol fuel cell anodes.
