Bipyridine-Confined Silver Single-Atom Catalysts Facilitate In-Plane C-O Coupling for Propylene Electrooxidation.

Chi, Mingfang; Zhao, Jiankang; Ke, Jingwen; Liu, Yan; Wang, Ruyang; Wang, Chuanhao; Hung, Sung-Fu; Lee, Tsung-Ju et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

The electrooxidation of propylene presents a promising route for the production of 1,2-propylene glycol (PG) under ambient conditions. However, the C-O coupling process remains a challenge owing to the high energy barrier. In this work, we developed a highly efficient electrocatalyst of bipyridine-confined Ag single atoms on UiO-bpy substrates (Ag SAs/UiO-bpy), which exposed two in-plane coordination vacancies during reaction for the co-adsorption of key intermediates. Detailed structure and electronic property analyses demonstrate that CH<sub>3</sub>CHCH<sub>2</sub>OH* and *OH could stably co-adsorb in a square planar configuration, which then accelerates the charge transfer between them. The combination of stable co-adsorption and efficient charge transfer facilitates the C-O coupling process, thus significantly lowering its energy barrier. At 2.4 V versus a reversible hydrogen electrode, Ag SAs/UiO-bpy achieved a record-high activity of 61.9 g<sub>PG</sub> m<sup>-2</sup> h<sup>-1</sup>. Our work not only presents a robust electrocatalyst but also advances a new perspective on catalyst design for propylene electrooxidation.