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

Abstract

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 WO_2.9/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. WO_2.9 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.