Development of highly active and durable Pt catalysts covered with silica

聚合物电解质燃料电池（PEFC）阴极Pt催化剂在低pH、高正电位和氧气环境下工作，由于金属Pt颗粒聚集、溶解和沉积，导致Pt催化剂失活。为了提高Pt金属在阴极条件下的耐久性，我们在碳负载的Pt催化剂上覆盖了几纳米厚的二氧化硅层。二氧化硅包覆Pt催化剂在氧还原反应中表现出较高的活性和良好的耐久性。此外，二氧化硅覆盖层可用于开发高活性和耐用的Pt-Co合金催化剂。

Pt catalysts at cathode in polymer electrolyte fuel cells (PEFC) are deactivated due to the aggregation of Pt metal particles and the dissolution and subsequent deposition of Pt metal, because the Pt catalysts should work under very severe conditions such as low pH, highly positive potential and oxygen atmosphere. We covered carbon-supported Pt catalysts with silica layers a few nanometers thick in order to improve the durability of Pt metal under the cathode conditions. The Pt catalysts covered with silica showed high activity and excellent durability for the oxygen reduction reaction. In addition, the coverage with silica can be applied to the development of highly active and durable Pt-Co alloy catalysts.