CeO2-supported Fe, Co and Ni toward CO2 hydrogenation: Tuning catalytic performance via metal-support interaction

The chemical transformation of CO 2 produces carbon compounds that can be used as precursors for the production of chemicals and fuels. Here, we investigated the activity and selectivity of the transition metals (Fe, Co, and Ni) supported on CeO 2 catalyst for CO 2 hydrogenation at atmospheric pressure. We found that Ni/CeO 2 shows the highest CO 2 conversion compared with Fe/CeO 2 and Co/CeO 2 . Besides, Co/CeO 2 and Ni/CeO 2 exhibit nearly 100% CH 4 selectivity while Fe/CeO 2 inclines to produce CO. The characterization results show that the metal-support interaction order is Fe/CeO 2  > Co/CeO 2  > Ni/CeO 2 , the weak metal-support interaction over Ni/CeO 2 benefits the activation of H 2 and then promotes the activity of CO 2 hydrogenation. Additionally, in situ DRIFTS results demonstrate that monodentate formate species rather than bidentate formate are the active intermediates. The main route of CO 2 hydrogenation to CH 4 is that CO 2 is firstly transformed to m-HCOO∗ and then direct hydrogenation of the m-HCOO∗ to CH 4 . This study provides insights into the understanding of the mechanisms of CO 2 hydrogenation on CeO 2 based catalysts.