Methanol cross-over effects from the anode to the cathode are important parameters for reducing catalytic performance in direct methanol fuel cells.A promising candidate catalyst for the cathode in direct methanol fue...Methanol cross-over effects from the anode to the cathode are important parameters for reducing catalytic performance in direct methanol fuel cells.A promising candidate catalyst for the cathode in direct methanol fuel cells must have excellent activity toward oxygen reduction reaction and resistance to methanol oxidation reaction.This review focuses on the methanol tolerant noble metal-based electrocatalysts,including platinum and palladium-based alloys,noble metal–carbon based composites,transition metal-based catalysts,carbon-based metal catalysts,and metal-free catalysts.The understanding of the correlation between the activity and the synthesis method,electrolyte environment and stability issues are highlighted.For the transition metal-based catalyst,their activity,stability and methanol tolerance in direct methanol fuel cells and comparisons with those of platinum are particularly discussed.Finally,strategies to enhance the methanol tolerance and hinder the generation of mixed potential in direct methanol fuel cells are also presented.This review provides a perspective for future developments for the scientist in selecting suitable methanol tolerate catalyst for oxygen reduction reaction and designing high-performance practical direct methanol fuel cells.展开更多
Recycling spent lithium-ion batteries(SLIBs)has become essential to preserve the environment and reclaim vital resources for sustainable development.The typical SLIBs recycling concentrated on separating valuable comp...Recycling spent lithium-ion batteries(SLIBs)has become essential to preserve the environment and reclaim vital resources for sustainable development.The typical SLIBs recycling concentrated on separating valuable components had limitations,including high energy consumption and complicated separation processes.This work suggests a safe hydrometallurgical process to recover usable metallic cobalt from depleted LiCoO_(2)batteries by utilizing citric acid as leachant and hydrogen peroxide as an oxidizing agent,with ethanol as a selective precipitating agent.The anode graphite was also recovered and converted to graphene oxide(GO).The above components were directly resynthesized to cobaltintegrated nitrogen-doped graphene(Co@NG).The Co@NG showed a decent activity towards oxygen reduction reaction(ORR)with a half-wave potential of 0.880 V vs.RHE,almost similar to Pt/C(0.888 V vs.RHE)and with an onset potential of 0.92 V vs.RHE.The metal-nitrogen-carbon(Co-N-C)having the highest nitrogen content has decreased the barrier for ORR since the reaction was enhanced for Co@NG-800,as confirmed by density functional theory(DFT)simulations.The Co@NG cathode catalyst coupled with commercial Pt-Ru/C as anode catalyst exhibits excellent performance for direct methanol fuel cell(DMFC)with a peak power density of 34.7 mW cm^(-2)at a discharge current density of120 m A cm^(-2)and decent stability,indicating the promising utilization of spent battery materials in DMFC applications.Besides,lithium was recovered from supernatant as lithium carbonate by coprecipitation process.This work avoids sophisticated elemental separation by utilizing SLIBs for other renewable energy applications,lowering the environmental concerns associated with recycling.展开更多
Sluggish kinetics of methanol oxidation reaction(MOR)and alkaline hydrogen evolution reaction(HER)even on precious Pt catalyst impede the large-scale commercialization of direct methanol fuel cell(DMFC)and water elect...Sluggish kinetics of methanol oxidation reaction(MOR)and alkaline hydrogen evolution reaction(HER)even on precious Pt catalyst impede the large-scale commercialization of direct methanol fuel cell(DMFC)and water electrolysis technologies.Since both of MOR and alkaline HER are related to water dissociation reaction(WDR),it is reasonable to invite secondary active sites toward WDR to pair with Pt for boosted MOR and alkaline HER activity on Pt.Mo_(2)C and Ni species are therefore employed to engineer NiPt-Mo_(2)C active site pairs,which can be encapsulated in carbon cages,via an in-situ self-confinement strategy.Mass activity of Pt in NiPt-Mo_(2)C@C toward HER is boosted to11.3 A mg_(pt)^(-1),33 times higher than that of Pt/C.Similarly,MOR catalytic activity of Pt in NiPt-Mo_(2)C@C is also improved by 10.5 times and the DMFC maximum power density is hence improved by 9-fold.By considering the great stability,NiPt-Mo_(2)C@C exhibits great practical application potential in DMFCs and water electrolysers.展开更多
Exploring non‐precious metal catalysts for the oxygen reduction reaction （ORR） is essential for fuel cells and metal–air batteries. Herein, we report a Fe‐N‐C catalyst possessing a high specific surface area （1...Exploring non‐precious metal catalysts for the oxygen reduction reaction （ORR） is essential for fuel cells and metal–air batteries. Herein, we report a Fe‐N‐C catalyst possessing a high specific surface area （1501 m2/g） and uniformly dispersed iron within a carbon matrix prepared via a two‐step pyrolysis process. The Fe‐N‐C catalyst exhibits excellent ORR activity in 0.1 mol/L NaOH electrolyte （onset potential, Eo=1.08 V and half wave potential, E1/2=0.88 V vs. reversible hydrogen electrode） and 0.1 mol/L HClO4 electrolyte （Eo=0.85 V and E1/2=0.75 V vs. reversible hydrogen electrode）. The direct methanol fuel cells employing Fe‐N‐C as the cathodic catalyst displayed promising per‐formance with a maximum power density of 33 mW/cm2 in alkaline media and 47 mW/cm2 in acidic media. The detailed investigation on the composition–structure–performance relationship by X‐ray diffraction, X‐ray photoelectron spectroscopy and Mo-ssbauer spectroscopy suggests that Fe‐N4, together with graphitic‐N and pyridinic‐N are the active ORR components. The promising direct methanol fuel cell performance displayed by the Fe‐N‐C catalyst is related to the intrinsic high catalytic activity, and critically for this application, to the high methanol tolerance.展开更多
Copper nanoparticles were prepared by the chemical reduction method.These copper particles were embedded into the polyvinylchloride(PVC)matrix as support and used as an electrode(PVC/Cu)for the oxidation of methanol f...Copper nanoparticles were prepared by the chemical reduction method.These copper particles were embedded into the polyvinylchloride(PVC)matrix as support and used as an electrode(PVC/Cu)for the oxidation of methanol fuel for improving the current response.The PVC/Cu electrodes were characterized by thermal gravimetric analysis(TGA)for thermal stability of the electrode,X-ray diffraction(XRD)for identification of copper nanoparticles in the electrode,Fourier transform infrared spectroscopy(FTIR)to identify the interaction between PVC and Cu and scan electron microscopy(SEM)with EDAX for the morphology of the electrode.The electrocatalytic activity of the electrode was characterized by the cyclic voltammetry,linear sweep voltammetry,and chronoamperometry techniques.An increase in the electrode activity was observed with the increase of copper quantity from 0.18 g(PVC/Cu-0.18 g)to 0.24 g(PVC/Cu-0.24 g)and the maximum was found at 0.24 g of copper in the electrode.Also,it was observed that the electrode achieved the maximum catalytic current in 0.5 mol/L CH3OH+1 mol/L Na OH solution.FTIR identified that water molecules,C—H group,copper nanoparticle and its oxide were available in the electrode.SEM images with EDAX showed that copper particles were properly embedded in the polyvinylchloride matrix.展开更多
Electrochemical impedance spectroscopy (EIS) is widely used in fuel cell impedance analysis. However, for ohmic resistance (R Ω), EIS has some disadvantages such as long test period and complex data analysis with equ...Electrochemical impedance spectroscopy (EIS) is widely used in fuel cell impedance analysis. However, for ohmic resistance (R Ω), EIS has some disadvantages such as long test period and complex data analysis with equivalent circuits. Therefore, the current interruption method is explored to measure the value of RΩ in direct methanol fuel cells (DMFC) at different temperatures and current densities. It is found that RΩ decreases as temperature increase, and decreases initially and then increases as current density increases. These results are consistent with those measured by the EIS technique. In most cases, the ohmic resistances with current interruption (R iR ) are larger than those with EIS (R EIS ), but the difference is small, in the range from –0.848% to 5.337%. The errors of R iR at high current densities are less than those of R EIS . Our results show that the R iR data are reliable and easy to obtain in the measurement of ohmic resistance in DMFC.展开更多
Supported PtRu/C catalysts used in direct methanol fuel cells (DMFCs) were prepared by a new modified polyol method. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and cyclic voltammograms (CVs) were ...Supported PtRu/C catalysts used in direct methanol fuel cells (DMFCs) were prepared by a new modified polyol method. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and cyclic voltammograms (CVs) were carried out to characterize the morphology, composition and the electrochemical properties of the PtRu/C catalyst. The results revealed that the PtRu nanoparticles with small average particle size (≈2.5 nm), and highly dispersed on the carbon support. The PtRu/C catalyst exhibited high catalytic activity and anti poisoned performance than that of the JM PtRu/C. It is imply that the modified polyol method is efficient for PtRu/C catalyst preparation.展开更多
PtRu supported on TiO2-embedded carbon nanofibers(PtRu/TECNF),which was recently reported as a highly-active catalyst for methanol oxidation,was applied to a direct methanol fuel cell(DMFC),and the power generation pe...PtRu supported on TiO2-embedded carbon nanofibers(PtRu/TECNF),which was recently reported as a highly-active catalyst for methanol oxidation,was applied to a direct methanol fuel cell(DMFC),and the power generation performance was compared to that using the commercial PtRu/C.Before the comparison,the effect of the catalyst loading on the power density of the DMFC was investigated using PtRu(18 wt%)/TECNF.The DMFC power density showed a maximum at about a 1.5 mg cm2 PtRu loading that corresponds to about an 80 mm layer thickness.A catalyst layer thicker than this value reduced the power density probably due to the concentration overvoltage.The PtRu content in the PtRu/TECNF was then increased to 30 wt%or more to reduce the layer thickness and to increase the power density.The DMFC performance was compared to that of different anode catalysts at a 1 mg cm2 PtRu loading.The power density was maximized using the PtRu30 wt%/TECNF,which showed a 173 mW cm2 at 353 K and had 66 mm layer thick,that was 26%higher than that of commercial PtRu/C.The current–voltage curve of the DMFC with the PtRu/TECNF suggested an improved mass transport overvoltage,but a little improvement in the activation one despite using the catalyst with about a 2 times higher activity compared to that of the commercial PtRu/C.This was attributed to the lower Pt utilization of the nanofiber catalyst layer.展开更多
The development of cathode oxygen reduction reaction(ORR)catalysts with high characteristics for practical,direct methanol fuel cells(DMFCs)has continuously increased the attention of researchers.In this work,interfac...The development of cathode oxygen reduction reaction(ORR)catalysts with high characteristics for practical,direct methanol fuel cells(DMFCs)has continuously increased the attention of researchers.In this work,interface-rich Au-doped PdBi(PdBiAu)branched one-dimensional(1D)alloyed nanochains assembled by sub-6.5 nm particles have been prepared,exhibiting an ORR mass activity(MA)of 6.40 A·mgPd^(−1) and long-term durability of 5,000 cycles in an alkaline medium.The MA of PdBiAu nanochains is 46 times and 80 times higher than that of commercial Pt/C(0.14 A·mgPt^(−1))and Pd/C(0.08 A·mgPd^(−1)).The MA of binary PdBi nanochains also reaches 5.71 A·mgPd^(−1).Notably,the PdBiAu nanochains exhibit high in-situ carbon monoxide poisoning resistance and high methanol tolerance.In actual DMFC device tests,the PdBiAu nanochains enhance power density of 140.1 mW·cm^(−2)(in O_(2))/112.4 mW·cm^(−2)(in air)and durability compared with PdBi nanochains and Pt/C.The analysis of the structure–function relationship indicates that the enhanced performance of PdBiAu nanochains is attributed to integrated functions of surficial defect-rich 1D chain structure,improved charge transfer capability,downshift of the d-band center of Pd,as well as the synergistic effect derived from“Pd-Bi”and/or“Pd-Au”dual active sites.展开更多
To enhance the CO-tolerance performance of anode catalysts for direct ethanol fuel cells,carbon nanotubes were modified by titanium dioxide （donated as CNTs@TiO2） and subsequently served as the support for the prepa...To enhance the CO-tolerance performance of anode catalysts for direct ethanol fuel cells,carbon nanotubes were modified by titanium dioxide （donated as CNTs@TiO2） and subsequently served as the support for the preparation of Pt/CNTs@TiO2 and Pt-Mo/CNTs@TiO2 electrocatalysts via a UV-photoreduction method.The physicochemical characterizations of the catalysts were carried out by using X-ray diffraction （XRD）,transmission electron microscopy （TEM）,X-ray photoelectron spectroscopy （XPS）,and infrared spectroscopy of adsorbed probe ammonia molecules.The electrocatalytic properties of the catalysts for methanol oxidation were investigated by the cyclic voltammetry technique.The results show that Pt-Mo/CNTs@TiO2 electrode exhibits the highest performance in all the electrodes.It is explained that,the structure,the oxidation states,and the acid-base properties of the catalysts are influenced due to the strong interaction between Ti and Mo species by adding TiO2 and MoOx to the Pt-based catalysts.展开更多
基金supported by the National Natural Science Foundations of China(22150410340)the Chongqing Science&Technology Commission(catc2018jcyjax0582)。
文摘Methanol cross-over effects from the anode to the cathode are important parameters for reducing catalytic performance in direct methanol fuel cells.A promising candidate catalyst for the cathode in direct methanol fuel cells must have excellent activity toward oxygen reduction reaction and resistance to methanol oxidation reaction.This review focuses on the methanol tolerant noble metal-based electrocatalysts,including platinum and palladium-based alloys,noble metal–carbon based composites,transition metal-based catalysts,carbon-based metal catalysts,and metal-free catalysts.The understanding of the correlation between the activity and the synthesis method,electrolyte environment and stability issues are highlighted.For the transition metal-based catalyst,their activity,stability and methanol tolerance in direct methanol fuel cells and comparisons with those of platinum are particularly discussed.Finally,strategies to enhance the methanol tolerance and hinder the generation of mixed potential in direct methanol fuel cells are also presented.This review provides a perspective for future developments for the scientist in selecting suitable methanol tolerate catalyst for oxygen reduction reaction and designing high-performance practical direct methanol fuel cells.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)the South Korea grant funded by the Korean government(MSIT)(2021R1A4A2000934,2023R1A2C3004336)+1 种基金The computational part of the work was supported by Department of Chemical and Biomolecular Engineering,Institute of Emergent Materials,Sogang University,via NRF Korea grant 2015M3D3A1A01064929a generous supercomputing time from KISTI。
文摘Recycling spent lithium-ion batteries(SLIBs)has become essential to preserve the environment and reclaim vital resources for sustainable development.The typical SLIBs recycling concentrated on separating valuable components had limitations,including high energy consumption and complicated separation processes.This work suggests a safe hydrometallurgical process to recover usable metallic cobalt from depleted LiCoO_(2)batteries by utilizing citric acid as leachant and hydrogen peroxide as an oxidizing agent,with ethanol as a selective precipitating agent.The anode graphite was also recovered and converted to graphene oxide(GO).The above components were directly resynthesized to cobaltintegrated nitrogen-doped graphene(Co@NG).The Co@NG showed a decent activity towards oxygen reduction reaction(ORR)with a half-wave potential of 0.880 V vs.RHE,almost similar to Pt/C(0.888 V vs.RHE)and with an onset potential of 0.92 V vs.RHE.The metal-nitrogen-carbon(Co-N-C)having the highest nitrogen content has decreased the barrier for ORR since the reaction was enhanced for Co@NG-800,as confirmed by density functional theory(DFT)simulations.The Co@NG cathode catalyst coupled with commercial Pt-Ru/C as anode catalyst exhibits excellent performance for direct methanol fuel cell(DMFC)with a peak power density of 34.7 mW cm^(-2)at a discharge current density of120 m A cm^(-2)and decent stability,indicating the promising utilization of spent battery materials in DMFC applications.Besides,lithium was recovered from supernatant as lithium carbonate by coprecipitation process.This work avoids sophisticated elemental separation by utilizing SLIBs for other renewable energy applications,lowering the environmental concerns associated with recycling.
基金financial support from the National Natural Science Foundation of China(Nos.21875224,22179121)the Fundamental Research Founds for National University,China University of Geosciences(Wuhan)。
文摘Sluggish kinetics of methanol oxidation reaction(MOR)and alkaline hydrogen evolution reaction(HER)even on precious Pt catalyst impede the large-scale commercialization of direct methanol fuel cell(DMFC)and water electrolysis technologies.Since both of MOR and alkaline HER are related to water dissociation reaction(WDR),it is reasonable to invite secondary active sites toward WDR to pair with Pt for boosted MOR and alkaline HER activity on Pt.Mo_(2)C and Ni species are therefore employed to engineer NiPt-Mo_(2)C active site pairs,which can be encapsulated in carbon cages,via an in-situ self-confinement strategy.Mass activity of Pt in NiPt-Mo_(2)C@C toward HER is boosted to11.3 A mg_(pt)^(-1),33 times higher than that of Pt/C.Similarly,MOR catalytic activity of Pt in NiPt-Mo_(2)C@C is also improved by 10.5 times and the DMFC maximum power density is hence improved by 9-fold.By considering the great stability,NiPt-Mo_(2)C@C exhibits great practical application potential in DMFCs and water electrolysers.
基金supported by the“Strategic Priority Research Program”of the Chinese Academy of Sciences(XDA09030104)the National Basic Research Program of China(973 Program,2012CB215500)+1 种基金the National Natural Science Foundation of China(2157625850823008)~~
文摘Exploring non‐precious metal catalysts for the oxygen reduction reaction （ORR） is essential for fuel cells and metal–air batteries. Herein, we report a Fe‐N‐C catalyst possessing a high specific surface area （1501 m2/g） and uniformly dispersed iron within a carbon matrix prepared via a two‐step pyrolysis process. The Fe‐N‐C catalyst exhibits excellent ORR activity in 0.1 mol/L NaOH electrolyte （onset potential, Eo=1.08 V and half wave potential, E1/2=0.88 V vs. reversible hydrogen electrode） and 0.1 mol/L HClO4 electrolyte （Eo=0.85 V and E1/2=0.75 V vs. reversible hydrogen electrode）. The direct methanol fuel cells employing Fe‐N‐C as the cathodic catalyst displayed promising per‐formance with a maximum power density of 33 mW/cm2 in alkaline media and 47 mW/cm2 in acidic media. The detailed investigation on the composition–structure–performance relationship by X‐ray diffraction, X‐ray photoelectron spectroscopy and Mo-ssbauer spectroscopy suggests that Fe‐N4, together with graphitic‐N and pyridinic‐N are the active ORR components. The promising direct methanol fuel cell performance displayed by the Fe‐N‐C catalyst is related to the intrinsic high catalytic activity, and critically for this application, to the high methanol tolerance.
文摘Copper nanoparticles were prepared by the chemical reduction method.These copper particles were embedded into the polyvinylchloride(PVC)matrix as support and used as an electrode(PVC/Cu)for the oxidation of methanol fuel for improving the current response.The PVC/Cu electrodes were characterized by thermal gravimetric analysis(TGA)for thermal stability of the electrode,X-ray diffraction(XRD)for identification of copper nanoparticles in the electrode,Fourier transform infrared spectroscopy(FTIR)to identify the interaction between PVC and Cu and scan electron microscopy(SEM)with EDAX for the morphology of the electrode.The electrocatalytic activity of the electrode was characterized by the cyclic voltammetry,linear sweep voltammetry,and chronoamperometry techniques.An increase in the electrode activity was observed with the increase of copper quantity from 0.18 g(PVC/Cu-0.18 g)to 0.24 g(PVC/Cu-0.24 g)and the maximum was found at 0.24 g of copper in the electrode.Also,it was observed that the electrode achieved the maximum catalytic current in 0.5 mol/L CH3OH+1 mol/L Na OH solution.FTIR identified that water molecules,C—H group,copper nanoparticle and its oxide were available in the electrode.SEM images with EDAX showed that copper particles were properly embedded in the polyvinylchloride matrix.
基金Supported by the National High Technology Research and Development Program of China （2007AA05Z150） the National Natural Science Foundation of China （50911140287 50973055）
文摘Electrochemical impedance spectroscopy (EIS) is widely used in fuel cell impedance analysis. However, for ohmic resistance (R Ω), EIS has some disadvantages such as long test period and complex data analysis with equivalent circuits. Therefore, the current interruption method is explored to measure the value of RΩ in direct methanol fuel cells (DMFC) at different temperatures and current densities. It is found that RΩ decreases as temperature increase, and decreases initially and then increases as current density increases. These results are consistent with those measured by the EIS technique. In most cases, the ohmic resistances with current interruption (R iR ) are larger than those with EIS (R EIS ), but the difference is small, in the range from –0.848% to 5.337%. The errors of R iR at high current densities are less than those of R EIS . Our results show that the R iR data are reliable and easy to obtain in the measurement of ohmic resistance in DMFC.
文摘Supported PtRu/C catalysts used in direct methanol fuel cells (DMFCs) were prepared by a new modified polyol method. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and cyclic voltammograms (CVs) were carried out to characterize the morphology, composition and the electrochemical properties of the PtRu/C catalyst. The results revealed that the PtRu nanoparticles with small average particle size (≈2.5 nm), and highly dispersed on the carbon support. The PtRu/C catalyst exhibited high catalytic activity and anti poisoned performance than that of the JM PtRu/C. It is imply that the modified polyol method is efficient for PtRu/C catalyst preparation.
基金the Element Innovation Project,Ministry of Education,Japan,and by KAKENHI(26289300).
文摘PtRu supported on TiO2-embedded carbon nanofibers(PtRu/TECNF),which was recently reported as a highly-active catalyst for methanol oxidation,was applied to a direct methanol fuel cell(DMFC),and the power generation performance was compared to that using the commercial PtRu/C.Before the comparison,the effect of the catalyst loading on the power density of the DMFC was investigated using PtRu(18 wt%)/TECNF.The DMFC power density showed a maximum at about a 1.5 mg cm2 PtRu loading that corresponds to about an 80 mm layer thickness.A catalyst layer thicker than this value reduced the power density probably due to the concentration overvoltage.The PtRu content in the PtRu/TECNF was then increased to 30 wt%or more to reduce the layer thickness and to increase the power density.The DMFC performance was compared to that of different anode catalysts at a 1 mg cm2 PtRu loading.The power density was maximized using the PtRu30 wt%/TECNF,which showed a 173 mW cm2 at 353 K and had 66 mm layer thick,that was 26%higher than that of commercial PtRu/C.The current–voltage curve of the DMFC with the PtRu/TECNF suggested an improved mass transport overvoltage,but a little improvement in the activation one despite using the catalyst with about a 2 times higher activity compared to that of the commercial PtRu/C.This was attributed to the lower Pt utilization of the nanofiber catalyst layer.
基金supported by the National Natural Science Foundation of China(No.21571038)Foundation of Guizhou Province(No.2019-5666)+3 种基金Education Department of Guizhou Province(No.2021312)State Key Laboratory of Coal Mine Disaster Dynamics and Control(Chongqing University,No.2011DA105287-ZR202101)the Open Fund of the Key Lab of Organic Optoelectronics&Molecular Engineering(Tsinghua University)State Key Laboratory of Physical Chemistry of Solid Surfaces(No.202009).
文摘The development of cathode oxygen reduction reaction(ORR)catalysts with high characteristics for practical,direct methanol fuel cells(DMFCs)has continuously increased the attention of researchers.In this work,interface-rich Au-doped PdBi(PdBiAu)branched one-dimensional(1D)alloyed nanochains assembled by sub-6.5 nm particles have been prepared,exhibiting an ORR mass activity(MA)of 6.40 A·mgPd^(−1) and long-term durability of 5,000 cycles in an alkaline medium.The MA of PdBiAu nanochains is 46 times and 80 times higher than that of commercial Pt/C(0.14 A·mgPt^(−1))and Pd/C(0.08 A·mgPd^(−1)).The MA of binary PdBi nanochains also reaches 5.71 A·mgPd^(−1).Notably,the PdBiAu nanochains exhibit high in-situ carbon monoxide poisoning resistance and high methanol tolerance.In actual DMFC device tests,the PdBiAu nanochains enhance power density of 140.1 mW·cm^(−2)(in O_(2))/112.4 mW·cm^(−2)(in air)and durability compared with PdBi nanochains and Pt/C.The analysis of the structure–function relationship indicates that the enhanced performance of PdBiAu nanochains is attributed to integrated functions of surficial defect-rich 1D chain structure,improved charge transfer capability,downshift of the d-band center of Pd,as well as the synergistic effect derived from“Pd-Bi”and/or“Pd-Au”dual active sites.
基金supported by the International Science and Technology Cooperation Program of China (No. 2006DFA61240)
文摘To enhance the CO-tolerance performance of anode catalysts for direct ethanol fuel cells,carbon nanotubes were modified by titanium dioxide （donated as CNTs@TiO2） and subsequently served as the support for the preparation of Pt/CNTs@TiO2 and Pt-Mo/CNTs@TiO2 electrocatalysts via a UV-photoreduction method.The physicochemical characterizations of the catalysts were carried out by using X-ray diffraction （XRD）,transmission electron microscopy （TEM）,X-ray photoelectron spectroscopy （XPS）,and infrared spectroscopy of adsorbed probe ammonia molecules.The electrocatalytic properties of the catalysts for methanol oxidation were investigated by the cyclic voltammetry technique.The results show that Pt-Mo/CNTs@TiO2 electrode exhibits the highest performance in all the electrodes.It is explained that,the structure,the oxidation states,and the acid-base properties of the catalysts are influenced due to the strong interaction between Ti and Mo species by adding TiO2 and MoOx to the Pt-based catalysts.
