中文摘要：

采用电化学老化试验研究了PtRu催化剂的活性衰减过程．结果表明，老化试验后，电催化剂的粒径有所增加，这在一定程度上减小了催化剂的表面积，降低了催化活性．更为严重的是，催化层中活性组分的流失改变了催化剂的组成，使催化剂对甲醇氧化反应的催化活性大幅降低．这是导致PtRu催化剂失活的重要原因．

英文摘要：

The performance degradation of PtRu catalyst is investigated by the electrochemical aging test. The results show that after the aging test, the particle size of the electrocatalyst increases to some extent, resulting in the loss of surface area and the lowered catalytic activity. Moreover, the loss of active components from the catalyst layer changes the catalyst composition, and makes the catalytic activity for the methanol oxidation reaction declined remarkably. This is thought to be the most important factor responsible for the activity loss of the PtRu catalyst.