LAUSR

Photocatalysis is a promising technology for conversion of the glycerol into formic acid, but photocatalytic oxidation of C-C bonds in glycerol exhibits poor selectivity towards formic acid because the photogenerated radicals (e.g., hydroxyl radicals) further oxidize formic acid to CO 2 . In this work, we revealed a synergy of photogenerated holes and superoxide radicals that achieved the selective oxidation of glycerol into formic acid over the TiO 2 catalyst. The charge separation of pristine TiO 2 was improved with the aid of oxygen, which resulted in efficient hole oxidation of the C-C bonds in glycerol to formic acid. Surface active species was controlled to prevent being converted to hydroxyl radicals on TiO 2 via controlling the oxygen and water contents , which solved the problem of formic acid peroxidation without sophisticated catalyst modifications. Mechanism studies suggested that glyceraldehyde and glycolaldehyde were the intermediates to generate formic acid. This work provides a green and efficient approach to produce formic acid as a liquid hydrogen carrier from bio-based alcohols.