In situDRIFTS examining the impact of indium doping on activity of CuIn/ZrO₂ catalyst for CO₂ hydrogenation to methanol

Abstract

We describe the synthesis of CuIn/ZrO2 catalysts via a facile mechanochemical synthesis method. In doping was demonstrated to promote the formation of strong Cu–In2O3 interactions and increase the number of Cu+ sites. The CuIn0.05/ZrO2 catalyst shows relatively high selectivity and space–time yield of methanol (~50% and ~1.25 , respectively) at 300°C and 5 MPa, outperforming those of the Cu/ZrO2 catalyst (~25% and ~1.12 , respectively). Time‐resolved in situ DRIFTS results acquired under various reaction conditions (typically H2/D2 isotope exchange) demonstrate that the surface Cu+–bound formate was the most reactive intermediate and the subsequent hydrogenation process should be the rate‐limiting step, which was positively promoted by the inclusion of In. The strong Cu–In2O3 interaction promotes a decrease in Cu0 sites, leading to a weak interaction of the Cu0‐bound CO intermediates, thus facilitating further hydrogenation of these species rather than releasing CO product.

CO2 Hydrogenation to Methanol over Mesoporous SiO2-Coated Cu-Based Catalysts

“…The aggregation of Cu particles at these conditions results in weak CO adsorption sites, making the intermediate to desorb as the major product . Chemical promotion of Cu/ZrO 2 and Cu/CeO 2 catalysts with low loadings of In 2 O 3 emerged as a strategy to increase the metal–support interaction, enhancing dispersion and decreasing and stabilizing Cu nanoparticles. − Although this system has shown promise for CO 2 hydrogenation, it still suffers from decreasing CH 3 OH selectivity by gradually increasing reaction temperature, indicating that there is room for further improvements.…”