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

Abstract

Abstract We report a plasma‐assisted CO 2 hydrogenation to CH 3 OH over Fe 2 O 3 /γ‐Al 2 O 3 catalysts, achieving 12% CO 2 conversion and 58% CH 3 OH 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 (H 2 ‐TPR), CO 2 and CO temperature programmed desorption (CO 2 /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 CO 2 conversion and CH 3 OH selectivity are attributed to the chemisorbed oxygen species on Fe 2 O 3 /γ‐Al 2 O 3 . Furthermore, the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) and TPD results illustrate that the catalysts with stronger CO 2 adsorption capacity exhibit a higher reaction performance. In situ DRIFTS gain insight into the specific reaction pathways in the CO 2 /H 2 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 CO 2 hydrogenation to CH 3 OH.