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

Abstract

AbstractThe 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 TiO2 support governs the selectivity in photothermal CO2 hydrogenation by tuning the metal‐support interactions (MSI). Small‐size TiO2 loading nickel (Ni/TiO2‐25) with enhanced MSI promotes photo‐induced electrons of TiO2 migrating to Ni nanoparticles, thus favoring the H2 cleavage and accelerating the CH4 formation (227.7 mmol g−1 h−1) under xenon light‐induced temperature of 360 °C. Conversely, Ni/TiO2‐100 with large TiO2 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/TiO2‐25 achieves the optimized CH4 rate (63.0 mmol g−1 h−1) with selectivity of 99.8 %, while Ni/TiO2‐100 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.