Experimental and theoretical study of Pd-Pt/In2O3 bimetallic catalysts for enhancing methanol production from CO2

Binary Pd/In2O3 and Pt/In2O3 catalysts exhibit technological potential in CO2 methanol synthesis. However, the key to achieving high productivity lies in resolving the unfavorable Pd-In alloy and Pt nanoparticles formation during the reaction. In this study, we present the surface restructuring of Pd-Pt/In2O3 catalysts under CO2 hydrogenation conditions. Detailed quasi-operando characterization and theory calculation reveal stable reconstruction driven by Pt with Pd. The bimetallic Pd-Pt inhibits the formation of both Pd-In alloy and Pt nanoparticles. Moreover, this restructuring process generates more oxygen vacancies during the reaction. These oxygen vacancies promote electron transfer from the indium oxide surface to the Pd-Pt clusters. Consequently, a shift occurs from interface-induced CO2 adsorption to cluster-induced adsorption. Thereby, the STY of methanol on Pd-Pt/In2O3 at 300 °C increased by approximately 20 % compared to that on Pd/In2O3 along. The findings highlight the crucial role of component-induced restructuring and oxygen vacancies in influencing the change of adsorption sites.