用络合还原法合成了用作直接甲酸燃料电池(DFAFC)中阳极碳载Pd(Pd/C)催化剂,并研究了电解液中的硅钨酸(SiWA)对甲酸在Pd/C催化剂电极卜氧化的促进作用.结果表明,SiWA不但能提高Pd/C催化剂对甲酸氧化的电催化活性,而且能增加电催化稳定性.这种促进作用与SiWA浓度有关.当SiWA浓度为0.40 g·L~(-1)时,促进作用最佳.当SiWA浓度大于0.40 g·L~(-1)时,由于过多的SiWA吸附在Pd/C催化剂上而覆盖了部分Pd活性位点,反而会降低促进作用.另外,由于SiWA在Pd/C催化剂上的吸附,降低了CO的吸附量,提高了Pd/C催化剂对甲酸氧化的电催化稳定性,也促进了甲酸通过直接途径氧化.%The carbon supported Pd (Pd/C) anodic catalyst in the direct formic acid fuel cell (DFAFC) was prepared with the complex reduction method and the promote action of silicotungstic acid (SiWA) in the electrolyte for the oxidation of formic acid at the Pd/C catalyst was investigated. It was found that SiWA could increase the electrocatalytic activity and stability for the oxidation of formic acid. The promote action is related to the SiWA concentration. When the SiWA concentration is 0.40 g·L~(-1) the promote action is the largest. However, when the SiWA concentration is higher than 0.40 g·L~(-1), overfull adsorbed SiWA would cover too much active points of the Pd/C catalyst, leading to a decrease in the promote action of SiWA. In addition, because the adsorption of SiWA on the Pd/C catalyst decreases the adsorption strength of CO on the Pd/C catalyst, SiWA could increase the electrocatalytic stability of the Pd/C catalyst for the oxidation of formic acid and also promote the oxidation of formic acid through the direct route.
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