Screening and design of active metals on dendritic mesoporous Ce0.3Zr0.7O2 for efficient CO2 hydrogenation to methanol

Abstract

Different active metals (PdCu, PdZn, CuZn, CuGa, and CuNi) over novel dendritic Ce0.3Zr0.7O2 (CZ) support were optimized to investigate their metal alloy interactions and further utilize their surface properties of the spherical morphology and the open pores of the dendritic support. The nature of the dendritic support offers a distinctive property in which it can increases the distribution of active sites. This variety of bimetallic phases withhold a distinctive interaction characteristic with the support that could promote CO2 hydrogenation to methanol by improving the oxygen vacancies and modifying the catalyst's reduction property. The addition of ZnO species into PdZn/CZ catalyst and the higher dispersion degrees of active metals could generate more oxygen vacancies that can improve and stabilize the methoxy species and promote the formate routes, thus, improve the activity of CO2 hydrogenation to methanol reaction. PdZn/CZ catalyst displayed the highest CO2 conversions (25.7 %), methanol yield (6.9 %), and superior 100 h long-term stability than those of other bimetallic catalysts. The best CO2 hydrogenation activity of the PdZn/CZ catalyst can be ascribed to the CO2 adsorption capabilities of CZ support that generated added oxygen vacancies and hydrogen dissociation performance of the Pd-ZnO active site.