Carbon‐Based Electron Buffer Layer on ZnO x −Fe ₅ C ₂ −Fe ₃ O ₄ Boosts Ethanol Synthesis from CO ₂ Hydrogenation

The conversion of CO 2 into ethanol with renewable H 2 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 −Fe 5 C 2 −Fe 3 O 4 , 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 CO 2 hydrogenation. This work provides a powerful electronic modulation strategy for catalyst design in terms of highly oriented synthesis.