Highly selective photothermal conversion of CO2 to ethylene using hierarchical boxwood ball-like Weyl semimetal WTe2 catalysts

Abstract

It is of significance to convert CO₂ into value-added carbon compounds under solar light. Here, we report a WTe₂ photothermal catalyst for the highly selective conversion of CO₂ into a commercially valuable chemical, ethylene (C₂H₄), by using the dual sites of W and Te under light illumination. It is found that (1) WTe₂ offers favorable formation of a *CHO intermediate at the W site, a lower energy barrier for the transfer of the *CHO intermediate from the W to the Te site, and a suitable W–Te distance for the C–C coupling to produce C₂H₄; (2) the photocatalysis and thermocatalysis synergistically cooperate with each other on WTe₂, significantly facilitating the CO₂ conversion. As a result, by designing a WTe₂ nanostructure with an enhanced photothermal effect, the reaction temperature can reach 185 °C under a 300 W Xe lamp, enabling a C₂H₄ production rate of 115.51 μmol g⁻¹ with a selectivity of C₂H₄ up to 88%, which exceeds all reported values of solar-driven C₂H₄ production.