Support effect on Ni-based mono- and bimetallic catalysts in CO2 hydrogenation

Aiming at a comprehensive understanding of support effects on Ni-based bimetallic catalyst for CO₂ hydrogenation, spectroscopy (DRIFTS) with CO as a probe molecule and temperature-programmed techniques were used 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 the higher activity and stability in CO₂ hydrogenation.