Recent progress of dual-site catalysts in emerging electrocatalysis: a review

Developing sustainable and clean electrochemical energy conversion technologies is a promising route to address energy scarcity and environmental pollution challenges, where electrocatalysts with high efficiency are of significance. To date, it is a huge challenge to prepare catalysts that facilitate multi-step reactions due to the difficulty in balancing the adsorption strength of multiple intermediates on a single catalytic site. Recently, owing to their multiple active centers and structural diversity, dual-site catalysts (DSCs), including catalysts containing heterointerfaces and heteroatoms, have attracted extensive interest to encourage multi-step reactions. Remarkable progress has been achieved by DSCs in the fields of electrocatalysis, such as hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and CO2 reduction reaction (CO2RR). In this review, we provide a systematic summary of the development of DSCs in the past years, as well as their applications in typical catalytic reactions. We categorized the DSCs into heterostructure catalysts, elemental doping catalysts, and diatomic-site catalysts, focusing on the catalytic mechanism of different types of DSCs catalysts. This review is aiming to shed light on the physical and chemical properties of the emergent DSCs and gain insights into the synergistic effect within the dual site in close proximity, thus offering guidelines to the catalyst design for multiple reactions in the future.