Manipulating interfacial hydrogen atom transfer for electrocatalytic CO₂ reduction to ethylene in bicarbonate...

Cu-based catalysts have been considered promising electrocatalysts for converting CO₂ into multi-carbon products (C₂₊ products). However, achieving selectivity toward a specific C₂₊ product remains challenging, necessitating the delicate design of catalytic sites to regulate the energy preference of reaction pathways. Herein, we introduced catalytic sites that evolve active hydrogen atoms (*H) on Cu surfaces to regulate electrocatalytic CO₂ hydrogenation pathways to achieve the selective production of ethylene. Ru single-atom site (Ru₁) was theoretically screened from 17 elements with 51 structures, exhibiting optimal activity in promoting hydrogenation of CO₂ reduction intermediates. The accordingly synthesized Ru₁-doped oxide-derived Cu (Ru₁-ODCu) catalyst delivered an ethylene selectivity of 82% in C₂₊ products with a Faradaic efficiency of 58.9% and a partial current density of 353.4 mA cm^-2 in KHCO₃ electrolyte. Kinetic isotopic and in situ spectroscopic analyses evidenced that the Ru₁ sites effectively promote intermediate hydrogenation by regulating *H transfer to intermediates, facilitating the energy-preferred pathway to ethylene production. These results provide insights into the design of Cu-based catalysts for converting CO₂ into specific products.