Support Effect on Ni-Based Mono- and Bimetallic Catalysts in CO2 Hydrogenation

Abstract

Aiming at a comprehensive understanding of support effects on Ni-based bimetallic catalyst for CO2 hydrogenation, spectroscopy (DRIFTS) with CO as probe molecule and temperature-programmed techniques to investigate the impact of different supports (MgO, CeO2, ZrO2) on Ni- and Ni,Fe catalysts. Kinetic parameters revealed that the higher selectivity to methanation for Ni and Ni,Fe supported on the reducible oxides (CeO2, ZrO2) is due to the inhibition of reverse water-gas shift reaction (RWGS) by hydrogen. A promoting effect of Fe on Ni was only observed on MgO-supported catalysts. In situ DRIFTS with CO adsorption showed different electronic properties of Ni sites with partially reduced oxide (i.e. ZrO2 and CeO2). H2-TPR and CO2-TPD confirmed the significant role of metal-support interaction (MSI) in CeO2-supported catalysts for CO2 activation. The MSI between Ni / Ni,Fe and reducible supports are crucial for catalytic performance, ultimately leading to higher activity and stability in CO₂ hydrogenation.