Direct Photocatalytic Conversion of Methane to Acetone Through a Synergistic Ta Single‐Atom/Ga Lewis Acid Catalyst

Abstract

ABSTRACT Direct photocatalytic conversion of methane to ≥ C3 oxygenates under ambient conditions remains highly challenging and largely unexplored due to the current carbon‐terminated adsorption configurations and insufficient concentration of intermediates. Herein, we demonstrated efficient γ‐Ga 2 O 3 quantum dot catalysts with high‐density Ta single atoms anchored at Ga IV vacancies (Ta 1 ‐Ga 2 O 3 QDs), featuring a synergistic Ta single‐atom/Ga Lewis acid architecture. The unsaturated d 0 ‐TaO 4 site stabilizes key acetyl intermediates in a distinctive oxygen‐terminated η 1 (O)‐CH 3 CO configuration, minimizing steric hindrance while enhancing carbonyl carbon electrophilicity, greatly facilitating the second C–C coupling step. Concurrently, Ga sites enrich –CH 3 intermediates for sequential C–C coupling conversion. The synergistic architecture achieved single‐step photocatalytic conversion of CH 4 and H 2 O to acetone with a yield of 86.7 µmol g −1 h −1 , with the carbon‐based selectivity of 56.2% or the liquid phase selectivity of 81.2%, and a 20.7% apparent quantum yield (AQY) at 254 nm, which has not been achieved by the current noble metal‐based photocatalysts. This work demonstrates the unique capability of unsaturated d 0 single‐atom sites for modulation of intermediate configurations, unlocking a pathway for ≥ C3 oxygenate synthesis from methane.