Efficient and Selective Hydroxyl-Mediated Photocatalytic Ethane Oxidation to Acetic Acid

Ethane offers a promising feedstock for sustainable acetic acid production. However, the chemical inertness of ethane and the multiple ethane oxidation steps greatly restrict the acetic acid productivity and selectivity. In this work, we report a photocatalytic strategy that promotes the generation of ^•OH to accelerate C(sp³)-H bond activation while steering sequential ethane oxidation to produce acetic acid. Our approach leverages spatially decoupled photoredox sites by integrating Pd nanoparticles onto titanium dioxide nanocrystals with mainly exposed {001} facets, enabling synergistic activation of molecular oxygen and water for enhanced ^•OH generation under mild conditions. This photocatalytic system achieves an acetic acid productivity of ∼5.65 mmol g_{photocatalyst}^-1 h^-1, producing an aqueous acetic acid solution of ∼40 mM in 102 h under light illumination with close to 100% acetic acid selectivity in liquid phase products. Our findings establish an efficient approach for selective alkane valorization to synthesize value-added chemicals at ambient temperature.