Abstract
The complex structural evolution of oxide catalysts during CO2 hydrogenation presents both challenges and opportunities for optimizing catalytic performance. This study demonstrates reaction-induced transformation of In2O3 particles into InOx nanolayers and subsurface In-Zr-O solid solutions on ZrO2 (denoted as In-ZrO2@InOx), significantly enhancing methanol synthesis efficiency. Under CO2/H2 reaction conditions, mobile metallic In0 generated from H2 reduction drives redispersion of In2O3 into surface InOx nanolayers, while subsequent inter-diffusion between In0 and Zr(CO3)2 leads to the formation of subsurface In-Zr-O solid solutions. Through precise control of temperature, pressure, and gas composition, we achieve optimal distribution of three distinct In species: In2O3 nanoparticles, surface InOx nanolayers, and subsurface In-Zr-O solid solutions. The engineered In-ZrO2@InOx catalyst exhibits a methanol space-time yield of 1.1 gmethanol/gcat/h with remarkable stability over 600 hours at 300 °C. Our findings highlight the crucial role of both surface and subsurface oxide species in oxide-catalyzed reactions and demonstrate the effectiveness of reaction-driven restructuring strategies for catalyst optimization.