PtCr合金的溶液制备及其电化学性质分析

催化剂性能的高低直接决定了燃料电池性能的好坏. 采用Pt基合金不仅能够降低催化剂Pt的载量, 而且往往能够提高催化剂的性能. 本工作用Cr作为合金化元素, 通过液相共沉淀的方式制备了不同比例的碳载PtCr合金催化剂. 采用高分辨透射电镜(HRTEM), 扫描电镜(SEM)等技术对合金催化剂的物理性质进行了测试. 结果表明, 获得的PtCr/C催化剂均匀地分散在Vulcan XC-72碳载体上, 粒度小于4 nm. 通过电化学测试, 研究了不同比例PtCr合金的电化学催化性能. 循环伏安测试表明, 本实验条件合成的合金催化剂在Pt/Cr原子比为2/1的时候, 对氧还原动力学有最佳的催化性能.

Synthesis of PtCr Alloy from Solutions and Its Electrochemical Analysis

To some extent, the behaviors of catalysts have great affection on the performance of the fuel cells. The application of Pt alloy can not only reduce consumption of Pt loaded on the catalyst layer, but also often raise catalyst performance simultaneously. Certain Pt-Cr alloys were synthesized with different atom ratio using co-precipitation and chemical reduction in aqueous phase, while high resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) were used to assess the physical properties of these alloys. From the results, the PtCr alloy could be observed to be uniformly deposited on the carbons and the diameters of alloy particles were less than 4 nm. Cyclic voltammetry was used to view the catalytic abilities of these alloys. The best atom ratio of alloy was Pt/Cr=2/1 because it exhibited the best catalytic ability to the oxygen reduction reaction in our experiment conditions.