Selective CO production from CO2 over a metal catalyst supported on perovskite oxide in the presence of excess hydrogen

Hydrogenation of carbon dioxide (CO2) to liquid fuels via an industrial catalytic reaction is the most effective strategy for the realization of carbon neutrality. The sequential reaction system of a reverse water-gas shift (RWGS) reaction followed by Fischer-Tropsch synthesis is a promising way to achieve this; hence, the development of catalysts with high conversion efficiency and selectivity for RWGS is required. We succeeded in the conversion of CO2 into carbon monoxide (CO) with a selectivity of 100% in the gas phase using a platinum-loaded perovskite oxide support composed of barium and zirconium, in which 10% of zirconium was substituted with yttrium (Pt/BaZr(0.9)Y0.1O(3-delta), Pt/BZY10) at 500 degrees C in the gas stream with H-2/CO2 = 3. Furthermore, a ruthenium-loaded catalyst (Ru/BZY10) afforded not only CO but also methane (CH4) as gaseous products. Kinetic analysis demonstrated that the activation energy was identical for both catalysts, and Fourier transform infrared spectroscopy clarified that the surface-adsorbed methoxy group was generated as a reaction intermediate only in the case of Ru/BZY10, which indicated the ability of the loaded metal for the dissociative adsorption of hydrogen. The present research is expected to provide a new methodology for the preparation of catalysts for the RWGS reaction and a quite important insight for the realization of carbon neutrality.