Atomically dispersed catalysts toward the oxygen evolution reaction in electrochemical water splitting: from catalyst design, performance to catalytic mechanism

Abstract

Electrochemical water splitting driven by renewable energy is a sustainable and environmentally friendly way to produce clean hydrogen fuel. Due to the slow reaction kinetics, the oxygen evolution reaction (OER) occurring in the anode side is regarded as the bottleneck of the overall water splitting and can only take place at a decent rate in the presence of efficient catalysts containing transition or noble metals. Given the huge demand for green hydrogen to decarbonize the energy sector and chemical industry, the global supply of metal catalysts has become a large concern. In this context, atomically dispersed catalysts (ADCs) have been proposed to be a promising alternative to the conventional nanoparticulate catalysts, enabling maximal utilization of metals and in the meantime good OER performance in the aqueous solutions of both alkali and acid. In view of huge potential application in the OER as well as water splitting, well-designed ADCs composing of transition metals (iron, cobalt or nickel) or noble metals (ruthenium or iridium) as active sites are summarized firstly in the current review. Next, the powerful tools in the investigation of structure-performance relationship and OER catalytic mechanism have been elaborated, including various in-situ characterizations and theoretical calculation. Finally, some challenges and perspectives for future development of ADCs are also listed, such as increasing the apparent activity, operation stability as well as possible device performance verification. The purpose of this review is to provide recent process in this field and our understanding in the future research of ADCs toward OER and to promote the further application in OER and water splitting.