高导电氧化物负载析氧电催化剂的构筑及结构-性能研究

析氧(OER)电催化剂是金属-空气电池、电解水制氢等新能源电化学系统中的核心材料。设计兼具良好导电性、耐电化学氧化性及高活性的OER催化剂，对促进相关技术的发展具有重要意义，也是当前研究难点。为此，项目提出基于Nb或Ta掺杂TiO2半导体的策略，制备高电导率的M-TiO2-x(M=Nb、Ta，x代表氧缺位)氧化物，作为导电、耐电化学氧化OER电催化剂载体材料；研究构筑具有三维有序大孔(3DOM)结构M-TiO2-x负载型纳米催化剂，基于TiO2-x表面强金属-载体相互作用，将超细钴基OER活性组分均匀稳定地锚定在3DOM内壁；基于次级结构设计策略，在孔道内部构筑钴氢(氧)氧化物纳米笼式“纳米反应器”，进一步提升催化剂性能；揭示所构筑催化剂导电性、微结构与催化性能间的本征构效关系，诠释OER催化机制，建立设计合成导电氧化物负载OER电催化剂的新方法，为高效稳定的OER电催化剂设计提供新思路。

Oxygen evolution reaction (OER) electrocatalysts are critical materials for many electrochemical systems such as metal-air batteries and water electrolysis for H2 production. The development of OER catalysts with good electrical conductivity, electrochemical oxidative resistivity and high catalytic activity is essential for the advances of these electrochemical technologies. However, the lack of such OER catalysts represents the main obstacle in this research field. To address this issue, we propose the fabrication of highly conductive and oxidation-resistive M-doped TiO2-x (M=Nb、Ta, x: oxygen defect) metal oxides to serve as support material for OER catalyst. From the developments in semiconductor physics, Nb or Ta-doping into TiO2 has been demonstrated as an effective strategy to obtain conductive oxides. Arranged in a three dimensional ordered macroporous (3DOM) architecture design, the 3DOM M-TiO2-x supported OER catalyst possessed good dispersion and firm anchoring of ultrafine cobalt catalyst on its 3DOM inner wall due to the strong metal-support interaction offered by oxygen-deficient TiO2-x surface. Additionally, a unique secondary structural design strategy of constructing a cobalt hydr(oxy)oxide nanocages “micro-reactor” into the macro-pores of 3DOM framework was proposed to further improves its catalytic performance. The underlying relation between its electrical conductivity, nanostructure, and catalytic performance was investigated, and the OER catalytic reaction mechanism would be unveiled. The proposed research establishes a new strategy for the development of conductive metal oxide supported OER catalysts, guiding the rational design of high-performance OER catalysts.