高电流密度PEM水电解OER催化材料研究现状与分析

Development and Analysis on Structural Design of OER Catalyst for PEM Water Electrolysis Under High Current Density

因强酸性、高过电位以及强氧化环境等问题,商业化质子交换膜(PEM)水电解析氧(OER)阳极需采用高载量的贵金属材料,且目前尚无替代的非贵金属催化剂,导致成本居高不下。以高电流密度(HCD)提升功率密度是PEM水电解未来发展趋势,但随着电流密度升高,水电解反应过电位也近似线性增长,需要催化材料更高的电导率和更快的物质运输,以降低电流和电解效率的损失。因此,开发高性能OER催化剂对推动PEM水电解制氢产业的发展意义重大。介绍了PEM水电解与可再生能源的契合性,从OER四电子反应机理出发,揭示OER催化剂研究意义;结合已有的研究报道,从形貌尺寸、表面结构、传电能力、电化学反应微环境等四方面,分析了高电流密度下OER催化材料的研究现状及其提高PEM水电解传输效率的原因;对高电流密度PEM水电解OER催化材料未来的发展趋势提出建议并进行了展望。

Due to the acidic,high overpotential,and oxidizing environment,the commercial proton exchange membrane(PEM)water electrolysis usually requires very high loading of platinum group metals(PGMs)for the oxygen reduction reaction(OER)on the anode,without PGM-free metal catalysts available at present and leading to high costs.Alternatively,using high current density(HCD)to increase the power density is a feasible way to reduce the cost of PEM water electrolysis.However,with the current density increase,the water electrolysis overpotential also increases in an approximate linearship,which presents a big challenge for the charge and mass transfer.Therefore,the development of catalysts with high OER activity plays an important role in improving the efficiency of the PEM water electrolysis.This review introduced the compatibility of PEM water electrolysis with the renewable energy sources,and the fundamentals of OER catalyst development on the point view of the 4-e OER mechanism was revealed.Then the recent development of the OER catalysts was summarized from four aspects,including morphologies,surface structures,in-plane transfer capacity,and electrochemical reaction environment,and the reasons of their enhancement on transfer efficiency were analyzed.Finally,suggestions and insights on the trends of OER catalytic materials for PEM water electrolysis at high current densities were provided.