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钯基纳米材料是甲酸电氧化反应的优良催化剂.本工作制备了两个系列钯基催化剂,并考察了聚苯胺对钯上甲酸电氧化反应的助催化作用.一种是以聚苯胺为基底,在其表面电沉积钯纳米粒子,制得n PANI/Pd催化剂(n表示聚合苯胺的循环数);另一种是直接在商业Pd/C催化剂表面电聚合苯胺,制得Pd/C/n PANI催化剂.结果显示,聚苯胺单独存在时对甲酸电氧化反应没有催化活性,但其可对钯上甲酸电氧化反应呈现明显的促进作用,且促进作用与聚苯胺的厚度(聚合循环数)密切相关.在两个系列催化剂中,15PANI/Pd和Pd/C/20PANI显示出最高的催化性能.15PANI/Pd中钯的质量比催化活性是纯钯催化剂的7.5倍;Pd/C/20PANI中钯的质量比催化活性和本征催化活性分别是商业Pd/C催化剂的2.3和3.3倍.钯催化性能的提升与聚苯胺和钯纳米粒子间的电子效应有关.
Palladium-based nanomaterials are excellent catalysts for formic acid electrooxidation.In this work, two series of palladium-based catalysts were prepared and investigated for the catalytic effect of polyaniline on the electro-oxidation of palladium on formic acid. One is based on polyaniline, Pd / C / n PANI (n represents the number of cycles of polymerization aniline) was prepared by electrodeposition of Pd nanoparticles on the surface of Pd / C catalyst. The other was Pd / C / n PANI Catalyst.The results showed that polyaniline had no catalytic activity on the oxidation of formic acid in the presence of polyaniline alone, but could significantly promote the electro-oxidation of palladium on formic acid and the promotion was closely related to the thickness of polyaniline (the number of polymerization cycles) . Among the two series of catalysts, 15PANI / Pd and Pd / C / 20PANI showed the highest catalytic performance. The mass ratio of palladium in 15PANI / Pd was 7.5 times that of pure palladium catalyst; The mass specific catalytic activity and intrinsic catalytic activity were 2.3 and 3.3 times that of the commercial Pd / C catalyst, respectively.The increase of the catalytic activity of Pd was related to the electronic effect between polyaniline and palladium nanoparticles.