中文摘要：

利用X射线能量色散（EDS）谱、X射线衍射（XRD）谱和电化学等技术研究了电解液中磷钨酸（PWA）对直接甲酸燃料电池（DFAFC）中甲酸在碳载Pd（Pd／C）催化剂上电氧化的促进作用．研究结果发现，因吸附的PWA能促进甲酸在Pd／C催化剂上的脱氢而加速了甲酸的电氧化．这种促进作用与PWA的浓度有关，当PWA的浓度低于0．15mg／mL时，该促进作用随PWA的浓度的增加而增加；当PWA的浓度高于0．15mg／mL时，过多吸附的PWA会覆盖过多Pd／C催化剂的活性点而使其电催化性能随PWA的浓度增大而降低．因此，当电解液中PWA的浓度为0．15mg／mL时，Pd／C催化剂对甲酸氧化的电催化性能最好．

英文摘要：

The promote action of phosphotungstic acid （PWA） in the electrolyte for the electrooxidation of formic acid at the carbon supported Pd （Pd/C） catalyst in the direct formic acid fuel cell（DFAFC） was investigated using the energy dispersive spectromettry （ EDS ）, X-ray diffraction （XRD） and electrochemical techniques. It was found that the adsorbed PWA could promote dehydrogen of formic acid, leading to the acceleration of the oxidation of formic acid at the Pd/C catalyst. Furthermore, the promote action is related to the PWA concentration.When the concentration of PWA is lower than 0. 15 mg/mL the promote action increases with increasing the concentration of PWA. However, when the concentration of PWA is higher than 0. 15 mg/ mL overfull adsorbed PWA would cover too more active points of the Pd/C catalyst, leading to that the promote action of PWA decreases with increasing the concentration of PWA. Therefore, when the Concentration of PWA is 0. 15 mg/mL the electrocatalytic performance of the Pd/C catalyst is best for the oxidation of formic acid.