Steering CO2 Hydrogenation to Methanol, Hydrocarbons, and Higher Alcohols over In2O3-Based Catalysts

Abstract

Catalytic hydrogenation of CO2 has been widely explored for producing chemicals and fuels, though its environmental and economic benefits remain context-dependent. Recently, In2O3-based catalysts have attracted significant interest because of their distinctive defect chemistry. These defect sites facilitate CO2 adsorption and activation and influence subsequent reaction pathways and product selectivity. This review highlights recent advances in In2O3-based catalytic systems for CO2 hydrogenation, emphasizing structure–activity relationships, modulation strategies, and underlying mechanisms. We begin by delineating the fundamental role of oxygen vacancies in CO2 adsorption and activation. Subsequently, we discuss various material design strategies, including defect engineering, interface regulation, and composite architecture construction, and analyze their impacts on catalytic performance. Furthermore, the product distribution is comprehensively examined, covering the formation pathways and selectivity control for C1 products (e.g., methanol), C2+ hydrocarbons (e.g., olefins and aromatics), and oxygenates. Emphasis is placed on product-oriented catalyst design and the evolution from intrinsic active-site regulation to multisite cooperation and reaction-pathway control. By linking catalyst architecture, complementary catalytic functions, intermediate evolution, and reaction pathways with product selectivity, we provide design principles for selective CO2 hydrogenation over In2O3-based catalysts.