Photo-thermal CO2 reduction with methane on group VIII metals: In situ reduced WO3 support for enhanced catalytic activity

Photo-thermal CO2 reduction with methane (CRM) is beneficial for solar energy harvesting and energy storage. The search for efficient photo-thermal catalysts is of great significance. Here, we reveal that group VIII metal catalysts supported by optical material WO3 are more effective for photo-thermal CRM, giving catalytic activities with visible light assistance that are 1.4–2.4 times higher than that achieved under thermal conditions. The activity enhancement (1.4–2.4 times) was comparable to that achieved with plasmonic-Au-promoted catalysts (1.7 times). Characterization results indicated that WO3 was partially reduced to WO3–x in situ under the reductive CRM reaction atmosphere, and that WO3–x rather than WO3 enhanced the activities with visible light assistance. Our method provides a promising approach for improving the activity of catalysts under light irradiation.