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

The chemical transformation of CO2 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 CeO2 catalyst for CO2 hydrogenation at atmospheric pressure. We found that Ni/CeO2 shows the highest CO2 conversion compared with Fe/CeO2 and Co/CeO2. Besides, Co/ CeO2 and Ni/CeO2 exhibit nearly 100% CH4 selectivity while Fe/CeO2 inclines to produce CO. The char-acterization results show that the metal-support interaction order is Fe/CeO2 > Co/CeO2 > Ni/CeO2, the weak metal-support interaction over Ni/CeO2 benefits the activation of H2 and then promotes the activity of CO2 hydrogenation. Additionally, in situ DRIFTS results demonstrate that monodentate formate species rather than bidentate formate are the active intermediates. The main route of CO2 hydrogenation to CH4 is that CO2 is firstly transformed to m-HCOO* and then direct hydrogenation of the m-HCOO* to CH4. This study provides insights into the understanding of the mechanisms of CO2 hydrogenation on CeO2 based catalysts.& COPY; 2023 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

This study investigates the activity and selectivity of transition metals (Fe, Co, and Ni) supported on CeO2 catalyst for CO2 hydrogenation. The results show that Ni/CeO2 exhibits the highest CO2 conversion, while Fe/CeO2 tends to produce CO. In addition, Co/CeO2 and Ni/CeO2 show nearly 100% selectivity towards CH4. The characterization results reveal that the weak metal-support interaction over Ni/CeO2 benefits the activation of H2 and promotes CO2 hydrogenation activity. The in situ DRIFTS results demonstrate that monodentate formate species are the active intermediates in CH4 production from CO2 hydrogenation.