Carbon-Based Electron Buffer Layer on ZnO_x -Fe₅ C₂ -Fe₃ O₄ Boosts Ethanol Synthesis from CO₂ Hydrogenation

The conversion of CO₂ into ethanol with renewable H₂ has attracted tremendous attention due to its integrated functions of carbon elimination and chemical synthesis, but remains challenging. The electronic properties of a catalyst are essential to determine the adsorption strength and configuration of the key intermediates, therefore altering the reaction network for targeted synthesis. Herein, we describe a catalytic system in which a carbon buffer layer is employed to tailor the electronic properties of the ternary ZnO_x -Fe₅ C₂ -Fe₃ O₄ , in which the electron-transfer pathway (ZnO_x →Fe species or carbon layer) ensures the appropriate adsorption strength of -CO* on the catalytic interface, facilitating C-C coupling between -CH_x * and -CO* for ethanol synthesis. Benefiting from this unique electron-transfer buffering effect, an extremely high ethanol yield of 366.6 g_EtOH  kg_cat ^-1  h^-1 (with CO of 10 vol % co-feeding) is achieved from CO₂ hydrogenation. This work provides a powerful electronic modulation strategy for catalyst design in terms of highly oriented synthesis.