Oxygen-tolerant photocatalytic conversion of simulated flue gas to ethylene

Abstract

Photocatalytic reduction of CO₂ in flue gas faces significant challenges due to the low CO₂ concentration and the presence of oxygen (O₂), which induces competitive oxygen reduction reactions, as well as the sluggish kinetics and complex product separation of oxidation half-reactions. Herein, we developed a dual copper (Cu)/platinum (Pt) atom on carbon nitride (CN-CuPt) photocatalyst, achieving synergistic ethylene production through low CO₂ concentration (i.e., 12% CO₂) reduction coupled with isopropanol oxidation to acetone for the first example. A benchmark photocatalytic ethylene yield of 778.6 μmolh⁻¹g_cat⁻¹ with a high selectivity of 87.0% is obtained, outperforming all the state-of-the-art CO₂ photocatalysts. What’s more, the CN-CuPt exhibits high oxygen tolerance, and more than 90% of its performance is retained under the interference of 5% oxygen due to oxygen inhibition by Cu species. Our strategy of regulating adsorption sites shows great potential for designing catalysts for practical photocatalytic reduction of flue gas.