Catalytic CO2 hydrogenation presents a promising route for converting CO2 into valuable products, contributing to the mitigation of net CO2 emissions. Supported Ru catalysts have recently gained considerable attention due to their tunability for 100% CO selectivity via the reverse water-gas shift pathway, effectively suppressing the competing methanation route. However, despite achieving full CO selectivity, the overall CO yield remains limited by low CO2 conversion, necessitating further improvement. In this work, CeO2 was introduced to modify a Ru/MgO single-atom catalyst for CO2 hydrogenation. The resulting Ru-CeO2/MgO catalyst, featuring abundant Ru-CeO2 interfacial sites, exhibited a favorable balance of CO2 conversion and CO selectivity, delivering the highest CO yield (32.5% at 500 °C), which is 9.0 and 1.8 times higher than that on Ru/MgO (3.6%) and Ru/CeO2 (18.4%), respectively. Although the CO selectivity was slightly compromised due to enhanced CO binding at Ru-CeO2 interfacial sites, H2 was more efficiently activated at these interfaces and readily reacted with CO2 adsorbed on CeO2-MgO surfaces, thereby boosting the CO2 hydrogenation activity and CO yield. This study underscores the critical role of Ru-metal oxide interface engineering in improving CO yield and advancing the rational design of highly efficient Ru catalysts for CO production from CO2 hydrogenation.
Ye et al. (Tue,) studied this question.