CO2 valorisation via reverse water-gas shift reaction using promoted Fe/CeO2-Al2O3 catalysts: Showcasing the potential of advanced catalysts to explore new processes design

Abstract

The RWGS reaction represents a direct approach for gas-phase CO2 upgrading. This work showcases the efficiency of Fe/CeO2-Al2O3 catalysts for this process, and the effect of selected transition metal promoters such as Cu, Ni and Mo. Our results demonstrated that both Ni and Cu remarkably improved the performance of the monometallic Fe-catalyst. The competition Reverse Water-Gas Shift (RWGS) reaction/CO2 methanation reaction was evident particularly for the Ni-catalyst, which displayed high selectivity to methane in the low-temperature range. Among the studied catalysts the Cu promoted sample represented the best choice, exhibiting the best activity/selectivity balance. In addition, the Cu-doped catalyst was very stable for long-term runs – an essential requisite for its implementation in flue gas upgrading units. This material can effectively catalyse the RWGS reaction at medium-low temperatures, providing the possibility to couple the RWGS reactor with a syngas conversion reaction. Such an integrated unit opens the horizons for a direct CO2 to fuels/chemicals approach.