Efficient Photothermal CO Hydrogenation into C2+ Hydrocarbons on in situ Generated Fe0 in Fe5C2 Active Sites via Cu-Promoted Hydrogen Dissociation and Spillover†

Photothermal hydrogenation of carbon monoxide (CO) holds the potential to generate valuable C₂₊ chemicals using renewable solar energy. However, its activity and selectivity towards C₂—C₃ alkanes are limited compared to conventional thermal catalysis. In this study, we developed a robust catalyst consisting of Cu/Fe₃O₄ nanoparticles on Mo₂CT_x MXene, showing enhanced photothermal C₂—C₃ production. The Cu component plays a crucial role in H₂ dissociation and subsequent H spillover, facilitating the in situ generation of Fe⁰ in Fe₅C₂ active sites and thus efficiently promoting photothermal CO hydrogenation. As a result, we achieved a 51.3% C₂₊ selectivity and 78.5% CO conversion at a high gas hourly space velocity (GHSV) of 12000 mL·g_cat⁻¹·h⁻¹ and 2.5 MPa in a flow reactor at 320 °C. The overall C₂—C₃ yield reached 23.6% with Cu/Fe₃O₄/Mo₂CT_x catalysts, marking a 2.8-fold increase compared to the performance of the bare Fe₃O₄/Mo₂CT_x catalyst.