Role of Oxygen Vacancies in Fe/Ru-Based Catalysts for the Reverse Water Gas Shift Reaction: Performance and...

The Reverse Water-Gas Shift (RWGS) reaction is a key process for converting carbon dioxide (CO₂) into carbon monoxide (CO), enabling downstream synthesis of fuels and chemicals while contributing to CO₂ emissions mitigation. This study investigates the performance of several Fe _x -Ru _y -based catalysts supported on different doped oxide materials (La-Al₂O₃, Ce-Al₂O₃, Sm-CeO₂, Si-Al₂O₃), with the goal of identifying a cost-effective and thermally stable alternative to purely noble metal systems. Catalysts were evaluated in atmospheric conditions up to 800 °C and subjected to repeated temperature ramp cycles to assess CO₂ conversion, CO selectivity, and long-term stability. Comprehensive characterization was performed using ICP-OES, BET, TPR, XRD, HRTEM, and XPS. The results reveal that optimizing the strength of the metal-support interaction, as well as the active metals ratio can have a significant impact, in terms of available active sites, which influences the catalytic performance, especially at lower temperatures (<500 °C). It was found that a ratio of 75% Fe and 25% Ru on Ce-doped Al₂O₃ provided this balance of properties. These findings provide insight into the design of robust, economically viable RWGS catalysts for efficient CO₂ utilization.