标题：Boosting the performance of Pt electro-catalysts toward formic acid electro-oxidation by depositing sub-monolayer Au clusters
作者：Xuanxuan Bi;Rongyue Wang;Yi Ding
作者机构：[Bi, X] School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China;[ Wang, R] School of Chemistry and Chemical Engineering 更多
通讯作者地址：[Ding, Y]Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China.
关键词：Formic acid;Electrocatalysis;Nanoparticles;Fuel cells;Under potential deposition
摘要：CO poisoning is the main obstacle to the application of Pt nanoparticles as anode catalysts in direct formic acid fuel cells (DFAFCs). Significant types of Pt alloys have been investigated, which often demonstrate evidently improved catalytic performance governed by difference mechanisms. By using a well-known electrochemical technique of under potential deposition and in situ redox replacement, sub-monolayer Au clusters are deposited onto Pt nanoparticle surfaces in a highly controlled manner, generating a unique surface alloy structure. Under optimum conditions, the modified Pt nanoparticles can exhibit greatly enhanced specific activity (up to 23-fold increase) at potential of -0.2 V vs. MSE toward formic acid electro-oxidation (FAEO). Interestingly, the mass specific activity can also be improved by a factor of 2.3 at potential of -0.35 V vs. MSE although significant amount of surface Pt atoms are covered by the over layer Au clusters. The much enhanced catalytic activity can be ascribed to a Pt surface ensemble effect, which induces change of the reaction path. Moreover, the sub-monolayer Au coating on the surface also contributes to the enhanced catalyst durability by inhibiting the Pt oxidation. These results show great potential to rationally design more active and stable nanocatalysts by modifying the Pt surface with otherwise inactive materials.