质子交换膜燃料电池Pt/C催化剂的回收再利用

回收质子交换膜燃料电池(PEMFC)失效的Pt/C催化剂,通过高温灼烧得到贵金属Pt渣。Pt渣经适量王水溶解、煮沸、浓缩和再稀释制成H2PtCl6溶液。以H2PtCl6为Pt的前驱体,采用无机胶体法重新制备出PEMFC用Pt/C催化剂。透射电子显微镜测试结果表明,采用优化的工艺条件所制备的Pt/C催化剂平均粒径为2.6nm,且分散性好、粒度均匀。X射线衍射分析表明,催化剂中Pt(111)晶面的相对含量较高,其面间距较小,且催化剂的结晶度略有降低,这些结构特点对催化氧还原反应是有利的。循环伏安法测试表明所制备的Pt/C催化剂对氢和氧电极过程具有良好的电催化性能。

Reprocessing of the ineffective Pt/C catalysts in PEMFC

Ineffective Pt/C catalysts were reprocessed in order to be reused in proton exchange membrane fuel cell (PEMFC). Pt residues were obtained by heat-treatment of ineffective Pt/C catalysts at a higher temperature in air, and then were dissolved by a suitable amount of aqua regia. The solution was boiled, concentrated and diluted again to form the H2PtCl6 solution. Pt/C catalysts were prepared with the H2PtCl6 solution by the inorganic colloid method.TEM results showed that the Pt/C catalyst with 2.6 nm platinum crystallites, a higher dispersion and a very narrow size distribution was achieved at optimal conditions. XRD analysis indicated the structural characteristic of higher relative content and smaller d-spacing of the Pt (111) crystal face, and lower crystallization degree of Pt. This benefited the acceleration of the oxygen reduction reaction in PEMFC. The cyclic voltammetry measurement exhibited a better electrocatalytic performance of prepared Pt/C catalysts for the oxygen and hydrogen electrode processes.