铱基催化剂在酸性析氧反应中的研究进展

降低对化石能源依赖,实现无碳能源需要构建以可再生能源(如太阳能、风能等)为主体的能源框架.氢气是无碳能源框架下的一种较为理想的能源载体,而电解水制氢技术能够有效制备环境友好的高纯氢气.其中,质子交换膜基(PEM)电解水技术相较碱性电解技术能够实现更高的质子导电性、电解效率、响应速度以及产物气体分离能力,展现出较高的应用...

Iridium-containing water-oxidation catalysts in acidic electrolyte

With the goal of constructing a carbon-free energy cycle, proton-exchange membrane (PEM) water electrolysis is a promising technology that can be integrated effectively with renewable energy resources to produce high-purity hydrogen. IrO2, as a commercial electrocatalyst for the anode side of a PEM water electrolyzer, can both overcome the high corrosion conditions and exhibit efficient catalytic performance. However, the high consumption of Ir species cannot meet the sustainable development and economic requirements of this technology. Accordingly, it is necessary to under-stand the OER catalytic mechanisms for Ir species, further designing new types of low-iridium cata-lysts with high activity and stability to replace IrO2. In this review, we first summarize the related catalytic mechanisms of the acidic oxygen evolution reaction (OER), and then provide general methods for measuring the catalytic performance of materials. Second, we present the structural evolution results of crystalline IrO2 and amorphous IrOx using in situ characterization techniques under catalytic conditions to understand the common catalytic characteristics of the materials and the possible factors affecting the structural evolution characteristics. Furthermore, we focus on three types of common low-iridium catalysts, including heteroatom-doped IrO2 (IrOx)-based cata-lysts, perovskite-type iridium-based catalysts, and pyrochlore-type iridium-based catalysts, and try to correlate the structural features with the intrinsic catalytic performance of materials. Finally, at the end of the review, we present the unresolved problems and challenges in this field in an attempt to develop effective strategies to further balance the catalytic activity and stability of materials un-der acidic OER catalytic conditions.