<i>In situ</i><scp>DRIFTS</scp> examining the impact of indium doping on activity of <scp>CuIn</scp>/<scp>ZrO<sub>2</sub></scp> catalyst for <scp>CO<sub>2</sub></scp> hydrogenation to methanol
Jiawei Chen, Bohong Wu, Yan Shao, Hongwei Guo, Huanhao Chen
Abstract
Abstract We describe the synthesis of CuIn/ZrO 2 catalysts via a facile mechanochemical synthesis method. In doping was demonstrated to promote the formation of strong Cu–In 2 O 3 interactions and increase the number of Cu + sites. The CuIn 0.05 /ZrO 2 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/ZrO 2 catalyst (~25% and ~1.12 , respectively). Time‐resolved in situ DRIFTS results acquired under various reaction conditions (typically H 2 /D 2 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–In 2 O 3 interaction promotes a decrease in Cu 0 sites, leading to a weak interaction of the Cu 0 ‐bound CO intermediates, thus facilitating further hydrogenation of these species rather than releasing CO product.