O’Connell, G.E.P.Tan, T.H.Yuwono, J.A.Wang, Y.Kheradmand, A.Jiang, Y.Kumar, P.V.Amal, R.Scott, J.Lovell, E.C.2024-09-172024-09-172024Applied Catalysis B: Environmental, 2024; 343:123507-1-123507-160926-33731873-3883https://hdl.handle.net/2440/142382Illuminating thermal catalysts with visible light is an effective strategy to reduce the thermal requirements of CO₂ methanation. In this study, we systematically varied the cobalt loading and properties of xCo/CeO₂ catalysts (between 0 and 10 wt%) to understand changes in the visible light-assisted reaction mechanism with cobalt loading. 10Co/CeO₂ had the highest CO₂ conversion of 90% at 450 ◦C. The light promoted the CO₂ conversion of all catalysts from 300 to 450◦C, peaking for 7.5Co/CeO₂ with a 125% improvement relative to thermal conditions (300 ◦C) before diminishing for 10Co/CeO₂. The light facilitated the conversion of the formate intermediate adsorbed onto CeO₂. In-situ DRIFTS and DFT unveiled a particle size trade-off between maximising CO₂ adsorbed at the Co-Ce interface while minimising CO₂ adsorbed onto cobalt, which is required for the best light enhancement. These findings underscore the importance of careful deposit size optimisation to unlock the lightassisted methanation’s full potential.en© 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).CO(2) methanation; Visible light illumination; Cobalt-ceria catalyst; Active metal; DRIFTSJournal article10.1016/j.apcatb.2023.1235072024-09-16677211Yuwono, J.A. [0000-0002-0915-0756]