Disclosing Support‐Size‐Dependent Effect on Ambient Light‐Driven Photothermal CO₂ Hydrogenation over Nickel/Titanium Dioxide

Abstract

Abstract The size of support in heterogeneous catalysts can strongly affect the catalytic property but is rarely explored in light‐driven catalysis. Herein, we demonstrate the size of TiO 2 support governs the selectivity in photothermal CO 2 hydrogenation by tuning the metal‐support interactions (MSI). Small‐size TiO 2 loading nickel (Ni/TiO 2 ‐25) with enhanced MSI promotes photo‐induced electrons of TiO 2 migrating to Ni nanoparticles, thus favoring the H 2 cleavage and accelerating the CH 4 formation (227.7 mmol g −1 h −1 ) under xenon light‐induced temperature of 360 °C. Conversely, Ni/TiO 2 ‐100 with large TiO 2 prefers yielding CO (94.2 mmol g −1 h −1 ) due to weak MSI, inefficient charge separation, and inadequate supply of activated hydrogen. Under ambient solar irradiation, Ni/TiO 2 ‐25 achieves the optimized CH 4 rate (63.0 mmol g −1 h −1 ) with selectivity of 99.8 %, while Ni/TiO 2 ‐100 exhibits the CO selectivity of 90.0 % with rate of 30.0 mmol g −1 h −1 . This work offers a novel approach to tailoring light‐driven catalytic properties by support size effect.