Ambient-pressure hydrogenation of CO 2 into long-chain olefins.

The conversion of CO 2 by renewable power-generated hydrogen is a promising approach to a sustainable production of long-chain olefins (C 4+ = ) which are currently produced from petroleum resources. The decentralized small-scale electrolysis for hydrogen generation requires the operation of CO 2 hydrogenation in ambient-pressure units to match the manufacturing scales and flexible on-demand production. Herein, we report a Cu-Fe catalyst which is operated under ambient pressure with comparable C 4+ = selectivity (66.9%) to that of the state-of-the-art catalysts (66.8%) optimized under high pressure (35 bar). The catalyst is composed of copper, iron oxides, and iron carbides. Iron oxides enable reverse-water-gas-shift to produce CO. The synergy of carbide path over iron carbides and CO insertion path over interfacial sites between copper and iron carbides leads to efficient C-C coupling into C 4+ = . This work contributes to the development of small-scale low-pressure devices for CO 2 hydrogenation compatible with sustainable hydrogen production.