NiFe2O4 spinel engineering for transcending the dilemma of activity–selectivity in CO2 hydrogenation to ethanol
Wenjie Xiang, Shuhei Yasuda, Lijun Zhang, Jiaqi Fan, Kazuki Tsukamoto, Yue Xin, Noritatsu Tsubaki
Abstract
CO2 hydrogenation to ethanol serves as a potential route for carbon neutrality and renewable energy utilization, while its practical application is severely limited by the activity-selectivity trade-off. This challenge primarily arises from the difficulty of C–C coupling and the occurrence of multiple side reactions. Herein, we design a NiFe2O4 spinel-modified Fe2O3 catalyst via a solid-state co-precipitation method, achieving a high CO2 conversion rate of 49.3% with an ethanol space–time yield of 883.7 mg·gcat.−1· h−1. Further mechanism investigation reveals that the incorporation of NiFe2O4 spinel benefits the formation of active Fe5C2 phase. Meanwhile, the interfacial sites between NiFe2O4 and Fe2O3 endow the catalyst with superior hydrogenation ability, which effectively inhibits excessive carbon chain growth and promotes the orientated synthesis of ethanol. This work proposes an inspiring NiFe2O4 spinel engineering method for the efficient production of multi-carbon oxygenates from CO2 hydrogenation. Turning CO2 into useful fuels is promising for cleaner energy but remains hard due to low efficiency. This study shows that a spinel-engineered catalyst boosts ethanol formation by promoting C–C coupling while suppressing further carbon-chain growth.