Support effect on Ni-based mono- and bimetallic catalysts in CO 2 hydrogenation.

Aiming at a comprehensive understanding of support effects on Ni-based bimetallic catalyst for CO 2 hydrogenation, spectroscopy (DRIFTS) with CO as a probe molecule and temperature-programmed techniques were used to investigate the impact of different supports (MgO, CeO 2 , ZrO 2 ) 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 (CeO 2 , ZrO 2 ) 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. ZrO 2 and CeO 2 ). H 2 -TPR and CO 2 -TPD confirmed the significant role of metal-support interaction (MSI) in CeO 2 -supported catalysts for CO 2 activation. The MSI between Ni/Ni,Fe and reducible supports are crucial for catalytic performance, ultimately leading to the higher activity and stability in CO 2 hydrogenation.