喷雾沉积法制备超低过电位多元金属化合物析氧催化剂协同效应研究

The oxygen evolution reaction (OER) is the key step of electrolysis hydrogen production. Because of its multi-electron and multi-step reaction, the catalyst is needed to accelerate the reaction rate. Iridium (Ir), ruthenium (Ru) and their compound OER catalysts are scarce and expensive. Traditional perovskite and spinel oxide catalysts have the problems of large OER overpotential, as well as the unclear mechanism of the high overpotential. Our preliminary study showed that the iron-cobalt binary metal oxide has a better catalytic performance. In this project, electrostatic spraying method will be employed to produce porous, three-component, uniformly dispersed iron-cobalt- molybdenum oxide on the surface of Ni foam for OER with ultra-low overpotential. The factors which influence the OER performance, such as proportion and dispersion form of each component and microstructure of multiple oxides, will be investigated in detail. From the angle of relationship between structure and performance of materials, surface adsorption, semiconductor band regulation and the other more interdisciplinary perspective to construct the model, the synergistic effect of three kinds of metal oxides for the OER overpotential will be studied. A method for the synthesis and regulation of polymetallic oxides by electrostatic spraying will be established. The design principle of polymetallic oxides OER catalyst will be established. The research of this project has important theoretical significance and practical value for the controlled preparation of homogeneous dispersed polymetallic compounds, the design of the high-performance catalyst for OER catalyst, and the mechanism research of polyphase interfacial catalytic reaction.

氧析出反应是电解水制氢的关键步骤，由于其为多电子、多步反应，需要催化剂以加快反应速率。铱、钌及其化合物型氧析出催化剂资源稀少、价格昂贵；传统钙钛矿和尖晶石型氧化物催化剂存在析氧过电位大、影响析氧过电位的机理不明确等问题。初步研究表明铁-钴二元金属氧化物具有较好的析氧催化性能。本项目拟采用静电喷雾法在泡沫镍表面沉积多孔的、三组分均匀分散的铁-钴-钼氧化物而制得具有超低过电位的析氧催化剂，探索各组分的比例和分散形式、多元氧化物微观结构等因素对析氧性能的影响，从材料结构与性能关系、表面吸附能、半导体能带调控等多学科交叉的角度来构建模型，研究三种金属氧化物对析氧过电位等参数的协同影响机制，建立静电喷雾合成和调控多元金属氧化物的方法，构建多元金属氧化物析氧催化剂设计原理。本项目的研究对均匀分散的多元金属化合物可控制备、高性能析氧催化剂的设计、多相界面催化反应机理研究具有重要的理论意义和实用价值。

能源短缺和环境污染是困扰人类社会发展的两大难题。寻找可再生能源和开发高效的能源存储和转换技术是应对能源问题的有效途径，而电催化反应是能量存储和转化的关键步骤。本项目通过喷雾沉积法制备了多元金属氧化物复合氧还原/析出催化剂，研究了多元金属氧化物组分构成、微观结构和协同效应，阐述了催化剂原子尺度结构与其性能的关系；制备了Pt-WO3修饰的泡沫镍催化剂，构建了基于ZIF-8模板和氮源的多孔Co-N-C催化剂；提出了表面修饰的铂纳米颗粒提高表面电导率和催化位点密度的机理，揭示了Zn及其MOF结构对催化剂性能影响机理。本项目探索了影响催化剂性能的因素，为高性能催化剂的设计和制备提供理论指导。此外，本项目探索了能源复合材料的界面特性，提出了复合电极结构调控及材料合成新方法，实现了高容量、长寿命的钠/钾离子存储。基于本项目研究工作共发表SCI论文7篇，培养研究生7人，完成了项目预定任务。