Boosting oxygen vacancies by modulating the morphology of Au decorated In₂O₃ with enhanced CO₂ hydrogenation activity to CH₃ OH

CO2 hydrogenation to methanol has become one of the most promising ways for CO2 utilization, however, the CO2 conversion rate and methanol selectivity of this reaction still need to be improved for industrial application. Here we investigated the structure-activity relationship for CO2 conversion to methanol of In2O3 -based catalysts by modulating morphology and decorating Au. Three different Au/In-2 O-3 catalysts were prepared, their activity follow the sequence of Au/In-2 O-3 -nanosphere (Au/In2O3 -NS) > Au/In2O3 -nanoplate (Au/In2O3 -NP) > Au/In-2 O-3 -hollow microsphere (Au/In2O3 -HM). Au/In2O3 -NS exhibited the best performance with good CO2 conversion of 12.7%, high methanol selectivity of 59.8%, and large space time yield of 0.32 gCH(3) OH /(hr center dot gcat ) at 300 C-degrees. The high performance of Au/In2O3 -NS was considered as the presence of Au. It contributes to the creation of more surface oxygen vacancies, which further promoted the CO2 adsorption and facilitated CO(2 )activation to form the formate intermediates towards methanol. This work clearly suggests that the activity of In2O3 catalyst can be effective enhanced by structure engineering and Au decorating. (c) 2023 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.