Co⁰ -Co^δ+ Interface Double-Site-Mediated C-C Coupling for the Photothermal Conversion of CO₂ into Light Olefins

Solar-driven CO₂ hydrogenation into multi-carbon products is a highly desirable, but challenging reaction. The bottleneck of this reaction lies in the C-C coupling of C₁ intermediates. Herein, we construct the C-C coupling centre for C₁ intermediates via the in situ formation of Co⁰ -Co^δ+ interface double sites on MgAl₂ O₄ (Co-CoO_x /MAO). Our experimental and theoretical prediction results confirmed the effective adsorption and activation of CO₂ by the Co⁰ site to produce C₁ intermediates, while the introduction of the electron-deficient state of Co^δ+ can effectively reduce the energy barrier of the key CHCH* intermediates. Consequently, Co-CoO_x /MAO exhibited a high C_2-4 hydrocarbons production rate of 1303 μmol g^-1  h^-1 ; the total organic carbon selectivity of C_2-4 hydrocarbons is 62.5 % under light irradiation with a high ratio (≈11) of olefin to paraffin. This study provides a new approach toward the design of photocatalysts used for CO₂ conversion into C₂₊ products.