Photocatalytic Methane Conversion to C1 Oxygenates over Palladium and Oxygen Vacancies Co‐Decorated TiO2

Abstract

Direct methane conversion to value‐added chemicals through photocatalysis is promising but still has great challenges in both efficient activation of C–H bonds and suppression of over‐oxidation. Herein, palladium nanoparticles and oxygen vacancies (OVs) co‐modified TiO2 photocatalysts are prepared and employed for photocatalytic CH4 conversion at room temperature. Under optimized conditions with O2 and water as the oxidants, a high yield of liquid oxygenates, e.g., 54 693 μmol g−1 h−1 with a nearly 100% selectivity has been achieved. Mechanism investigations reveal that Pd and OVs synergistically promote charge separation, with Pd and OVs acting as hole and electron acceptors, respectively. Isotopic experiments elucidate that both H2O and O2 are oxygen sources for oxygenate production, where O2 is the predominant one.