This research aims at increasing the utilization of platinum-ruthenium alloy(Pt-Ru)catalysts and thus lowering the catalyst loading in anodes for methanol electrooxidation.The direct methanol fuel cell’s(DMFC)anodic ...This research aims at increasing the utilization of platinum-ruthenium alloy(Pt-Ru)catalysts and thus lowering the catalyst loading in anodes for methanol electrooxidation.The direct methanol fuel cell’s(DMFC)anodic catalysts,Pt-Ru/C,were prepared by chemical reduction with a reduc-ing agent added in two kinds of solutions under different circumstances.The reducing agent was added in hot solution with the protection of inert gases or just air,and in cold solu-tion with inert gases.The catalysts were treated at different temperatures.Their performance was tested by cyclic voltam-metry and potentiostatic polarization by utilizing their inher-ent powder microelectrode in 0.5 mol/L CH3OH and 0.5 mol/L H2SO4 solution.The structures and micro-surface images of the catalysts were determined and observed by X-ray diffrac-tion and transmission electron microscopy,respectively.The catalyst prepared in inert gases showed a better catalytic performance for methanol electrooxidation than that prepared in air.It resulted in a more homogeneous distribution of the Pt-Ru alloy in carbon.Its size is small,only about 4.5 nm.The catalytic performance is affected by the order of the reducing agent added.The performance of the catalyst pre-pared by adding the reductant at constant temperature of the solution is better than that prepared by adding it in the solu-tion at 0℃ and then heating it up to the reducing temperature.The structure of the catalyst was modified,and there was an increase in the conversion of ruthenium into the alloyed state and an increase in particle size with the ascension of heat treatment temperature.In addition,the stability of the catalyst was improved after heat treatment.展开更多
基金supported financially by Heilongjiang Natural Science Foundation(B0201)Harbin Institute of Technology(HIT 2002.39).
文摘This research aims at increasing the utilization of platinum-ruthenium alloy(Pt-Ru)catalysts and thus lowering the catalyst loading in anodes for methanol electrooxidation.The direct methanol fuel cell’s(DMFC)anodic catalysts,Pt-Ru/C,were prepared by chemical reduction with a reduc-ing agent added in two kinds of solutions under different circumstances.The reducing agent was added in hot solution with the protection of inert gases or just air,and in cold solu-tion with inert gases.The catalysts were treated at different temperatures.Their performance was tested by cyclic voltam-metry and potentiostatic polarization by utilizing their inher-ent powder microelectrode in 0.5 mol/L CH3OH and 0.5 mol/L H2SO4 solution.The structures and micro-surface images of the catalysts were determined and observed by X-ray diffrac-tion and transmission electron microscopy,respectively.The catalyst prepared in inert gases showed a better catalytic performance for methanol electrooxidation than that prepared in air.It resulted in a more homogeneous distribution of the Pt-Ru alloy in carbon.Its size is small,only about 4.5 nm.The catalytic performance is affected by the order of the reducing agent added.The performance of the catalyst pre-pared by adding the reductant at constant temperature of the solution is better than that prepared by adding it in the solu-tion at 0℃ and then heating it up to the reducing temperature.The structure of the catalyst was modified,and there was an increase in the conversion of ruthenium into the alloyed state and an increase in particle size with the ascension of heat treatment temperature.In addition,the stability of the catalyst was improved after heat treatment.
