非负载型三维一体化氧还原气体多孔电极的构筑与催化特性研究

发展低成本、高性能的氧还原催化剂是实现燃料电池商业化的关键。针对现有氮掺杂碳（N/C）催化剂存在的掺氮效率低、导电性差、活性差等一系列问题。本申请提出“三维一体化氧还原气体多孔电极”的构筑方案，通过原位聚合将含氮聚合物前驱体包覆在具有三维网状开孔结构和高开孔率的三聚氰胺骨架上，利用二氧化硅的固形和限域作用，控制聚合物高温碳化时的结构形貌转换，避免聚合物在高温碳化过程中的结构坍塌、烧结及热解损失，利用高温碳化时产生的水、气调控表界面产生的缺陷、孔隙和掺杂类型，确保N/C催化剂活性位点尽可能地处在 “气/固/液”三相界面上，实现催化中心利用率的全面提升。

Developing catalysts with high performance and low cost for oxygen reduction reaction (ORR) has been one of the major challenges for large-scale application of fuel cells. Nitrogen-doped carbon (N/C) catalyst is one of the most promising alternative non-noble metal catalysts of Pt catalysts. However, its catalytic activity is still at a low level compared to Pt catalysts due to low electron conductivity and insufficient active sites. In this application, we provide a novel strategy to prepare nitrogen-doped carbon three-dimensional porous electrode by the direct carbonization of nitrogen-rich polymer coated foam, which was sealed on a silica nano-reactor. By means of the limited space and quasi-closed characteristics of the silica nano-reactor, the collapsing, sintering and losing of nitrogen-rich polymer foam at high temperature process can be alleviated. The gasification in such a closed nano-reactor creates a large number of active sites for O2 and water, which is conducive to improve the mass transfer efficiency and increase the exposure of active sites to the three-phase zone.