核-壳型PEM电解水制氢阳极铱基催化剂的研究进展

Research Progress of Core-Shell Anode Iridium-Based Catalyst Prepared by PEM Water Electrolysis for Hydrogen Production

基于可再生能源电力的质子交换膜(PEM)电解水制氢技术是现阶段大规模制取绿氢的有效方法之一,其具有工作效率高、制氢纯度高、电解槽及系统结构紧凑、本质安全性高、负荷波动可调节范围大、适合快速启停等优点。阳极反应是速率控制步骤,阳极催化剂的活性和稳定性以及成本是目前制约PEM电解水制氢大规模发展的重要因素之一,目前主要的阳极商业催化剂为IrO2或Ir黑催化剂,Ir储量少且价格昂贵,因此当务之急是寻求能够同时降低催化剂成本和提高催化剂性能的有效方法。具有核-壳结构的Ir-M催化剂利用核与壳之间的电子效应和应变效应的协同调节,不仅可以降低贵金属Ir的用量,而且能显著提高催化活性,笔者综述了核-壳结构型Ir基PEM电解水制氢阳极催化剂的主要制备方法,包括胶体法(晶种生长法)、一步合成法、选择性脱合金法等,分析了反应机理,阐述了核壳结构电催化剂特用的表征方法,最后对Ir基核-壳结构催化剂的研究发展趋势做出了展望。

Proton-exchange membrane(PEM)hydrogen production technology by water electrolysis through renewable energy power is one of the most effective methods for producing green hydrogen in a large scale at this stage,which is characterized by high work efficiency,high-purity hydrogen production,compact electrolytic cell and system structure,high intrinsic safety,large adjustable range of load fluctuation,and suitablity for quick start and stop.Anode reaction is a rate-determining step,and the activity and stability as well as cost of anode catalyst are one of the important factors that currently restrict the large-scale development of hydrogen production by PEM water electrolysis.At present,the main commercial anode catalyst is IrO2 or Ir-black catalyst,while iridium is expensive due to the small reserves.Therefore,it is imperative to find effective ways to reduce catalyst cost and improve catalyst performance.The Ir-M catalyst with core-shell structure makes use of the cooperative regulation of electronic effect and strain effect between the core and the shell,which not only can effectively reduce the use of the precious metal Ir,but also can significantly improve catalytic activity.This paper summarizes the main preparation methods for the Ir-based PEM anode catalyst with core-shell structure by water electrolysis,including colloidal method(seeded growth method),one-step synthesis method and selective de-alloying method,analyzes the reaction mechanism,describes the characterization methods specifically for the electrocatalyst with core-shell structure,and finally looks forward to the future research and development trends of the iridium-based core-shell structured catalyst.