Enhanced Photothermal Catalytic CO2 Reduction to High Selective C2H4 by Cooperative Interaction of Oxygen Vacancy and WTe2 Semimetal Cocatalyst In Situ Grown on WO3 Hollow Spheres

Photothermal catalytic CO2 reduction offers a dual solution to the greenhouse effect and energy crisis. Enhancing this process through the development of effective cocatalysts has proven to be a practical approach. In this study, the WO2.9/WTe2 photothermal catalyst was synthesized via an in situ growth method. The catalyst achieved an ethylene production rate of 122.9 μmol·g–1, with a selectivity of 78%. Even at a reactor temperature of 240 °C, the ethylene yield reached 475.3 μmol·g–1. This improvement in yield can be attributed to the synergistic effects of the semimetal cocatalyst WTe2 and oxygen vacancies, which exhibit superior catalytic activity. In situ DRIFTS and DFT analyses highlighted the critical role of intermediary aldehyde groups in facilitating C–C coupling. WO2.9 contributes by modulating the band gap and enhancing CO2 adsorption via oxygen vacancies, while WTe2 effectively captures intermediate aldehyde groups, fostering a surface rich in intermediates and promoting C–C bond formation. Additionally, thermal energy accelerates CO2 activation and the C–C coupling process, creating optimal conditions for generating C2+ products. This research provides innovative strategies for designing photothermal catalysts and new insights into producing multicarbon fuels through a synergistic photothermal catalytic approach.