磷酸燃料电池催化剂在运行中的形态变化  

The Agglomeration and Dissolution of Pt/C Catalyst in Phosphoric Acid

作　　者：张俊喜[1] 徐娜[2] 魏增福[3] 

机构地区：[1]上海电力学院电化学研究室国家电力公司热力设备腐蚀与防护重点实验室,上海200090 [2]东北电力学院应用化学系,吉林吉林132012 [3]广东省电力试验研究所,广东广州510600

出　　处：《上海电力学院学报》2006年第1期75-78,83,共5页Journal of Shanghai University of Electric Power

基　　金：上海市重点培育学科(P1304);上海市教委重点学科建设项目(第4期)资助

摘　　要：运用电化学方法测定了Pt/C催化剂在磷酸中不同时效阶段的电化学活性面积,同时采用XRD/TEM分析了Pt/C催化剂在时效过程中尺寸的变化,并运用分光光度法测量电极所在的磷酸中铂的含量,考察了铂/碳电极在不同情况下的溶解情况.结果表明:催化剂在时效过程中,随着时间的增加电化学活性面积逐渐减小,而Pt/C催化剂的粒径随着时间的增加逐渐增加;在开路电位下,催化剂的溶解量随时间的增加而增大,而催化剂在阴极极化下不发生溶解.分析讨论了碳载铂颗粒的增大机理和不同状态下铂的溶解机理.The effects of the crystallite size and the dissolution on the electrocatalytic behavior of carbon-supported platinum ageing in phosphoric acid are investigated by using XRD/TEM and electrochemical measurement. The distribution of crystallite size of Pt tends to shift to right with increasing ageing time, meanwhile the dissolution of Pt takes place under open circuit potential but not under cathodic polarization. Result shows that the decrease of electrochemical surface areas of Pt/C catalyst is responsible for the agglomeration and dissolution of platinum crystallites. The agglomeration of Pt crystallite can be explained by the migration and coalescence growth mechanism because there is no potential effect during the growth of Pt crystallite. The mechanism of the agglomeration and the dissolution of carbon-supported platinum are discussed.

关 键 词：磷酸燃料电池 催化剂 时效 团聚 溶解 

分 类 号：TM911[电气工程—电力电子与电力传动] O614[理学—无机化学]