RuCo/ZrO 2 Tandem Catalysts with Photothermal Confinement Effect for Enhanced CO 2 Methanation.

Photothermal CO 2 methanation reaction represents a promising strategy for addressing CO 2 -related environmental issues. The presence of efficient tandem catalytic sites with a localized high-temperature is an effective pathway to enhance the performance of CO 2 methanation. Here the bimetallic RuCo nanoparticles anchored on ZrO 2 fiber cotton (RuCo/ZrO 2 ) as a photothermal catalyst for CO 2 methanation are prepared. A significant photothermal CO 2 methanation performance with optimal CH 4 selectivity (99%) and rate (169.93 mmol g cat -1 h -1 ) is achieved. The photothermal energy of the RuCo bimetallic nanoparticles, confined by the infrared insulation and low thermal conductivity of the ZrO 2 fiber cotton (ZrO 2 FC), provides a localized high-temperature. In situ spectroscopic experiments on RuCo/ZrO 2 , Ru/ZrO 2 , and Co/ZrO 2 indicate that the construction of tandem catalytic sites, where the Co site favors CO 2 conversion to CO while incorporating Ru enhances CO * adsorption for subsequent hydrogenation, results in a higher selectivity toward CH 4 . This work opens a new insight into designing tandem catalysts with a photothermal confinement effect in CO 2 methanation reaction.