Review of Emerging Atomically Precise Composite Site‐Based Electrocatalysts

Abstract

Atomically precise composite site‐based catalysts with new electrocatalytic synergistic mechanisms and enhanced electrocatalytic activities have emerged as a frontier in the electrocatalysis community. This topical review focuses on the recent research advances of atomically precise metal composite sites‐based electrocatalysts. This work first demonstrates an overview of the configurations of atomically precise composite sites, including a discussion of the advanced methods employed for understanding the composite sites. The review then provides a comprehensive organization of the previously reported methodologies of synthesizing electrocatalysts with atomically precise composite sites. Representative case studies are provided, starting from the simple one‐step pyrolysis strategy to the species‐by‐species multi‐step pyrolysis strategy. Based on the preceding discussions of the catalyst materials, the review further discusses the unique electrocatalysis mechanisms raised by the composite sites, that are different from the routine single species sites. The electrocatalytic systems mainly involve the oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, nitrogen reduction reaction, and carbon dioxide reduction reaction. The themes of this section include the true active center determination for composite sites and various types of electrocatalytic synergy mechanisms. Finally, critical unanswered questions and remaining challenges, as well as promising underexplored research directions are identified.

Local structural environment of single-atom catalysts

“…Nanotechnology has flourished in the past decades, driving the development of nanocatalysis science and technology and resulting in nanocatalysts emerging as the times require. 5–8 Compared with traditional catalysts, the size of the active species of nanocatalysts is nanoscale, therefore nanocatalysts have higher specific surface areas with more exposed reaction sites. 9–11 Due to the unique physicochemical properties of catalysts at the nanoscale, such as crystal face effects, size effects and synergistic effects, nanocatalysts exhibit excellent catalytic performances in many chemical reactions.…”

Phosphorus-rich CoP4@N–C nanoarrays for efficient nitrate-to-ammonia electroreduction

“…have attracted widespread attention and in-depth research in the field of electrocatalysis. 24,28–31 Among them, cobalt phosphide has been widely applied in electrocatalysis due to its high catalytic activity and stability. 32 Designing heterogeneous structures, such as metal/carbon hybrid materials, can effectively promote electron transfer and provide a large number of stable electroactive sites.…”

Atomically dispersed multi-site catalysts: bifunctional oxygen electrocatalysts boost flexible zinc–air battery performance

“…47–49 Especially, atomically dispersed catalysts, which provide an exceptionally high surface area, facilitate efficient energy conversion and storage when operating with a limited electrode area in FZABs. 50,51 Furthermore, the exceptional conductivity of the catalysts at the atomic level contributes to an enhancement in electron transport efficiency, thereby further enhancing the efficacy of electrochemical reactions. 52 Therefore, revealing the structural properties of the active center and elucidating the reaction pathway at the atomic level are crucial for advancing the development of atomically dispersed catalysts for FZABs.…”