Plasma‐driven CO2 hydrogenation to CH3OH over Fe2O3/γ‐Al2O3 catalyst

Abstract

AbstractWe report a plasma‐assisted CO2 hydrogenation to CH3OH over Fe2O3/γ‐Al2O3 catalysts, achieving 12% CO2 conversion and 58% CH3OH selectivity at a temperature of nearly 80°C atm pressure. We investigated the effect of various supports and loadings of the Fe‐based catalysts, as well as optimized reaction conditions. We characterized catalysts by X‐ray powder diffraction (XRD), hydrogen temperature programmed reduction (H2‐TPR), CO2 and CO temperature programmed desorption (CO2/CO‐TPD), high‐resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM), x‐ray photoelectron spectroscopy (XPS), Mössbauer, and Fourier transform infrared (FTIR). The XPS results show that the enhanced CO2 conversion and CH3OH selectivity are attributed to the chemisorbed oxygen species on Fe2O3/γ‐Al2O3. Furthermore, the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) and TPD results illustrate that the catalysts with stronger CO2 adsorption capacity exhibit a higher reaction performance. In situ DRIFTS gain insight into the specific reaction pathways in the CO2/H2 plasma. This study reveals the role of chemisorbed oxygen species as a key intermediate, and inspires to design highly efficient catalysts and expand the catalytic systems for CO2 hydrogenation to CH3OH.