State Key Laboratory of Catalysis (SKLC), Dalian National Laboratory for Clean Energy (DNL), Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China.
University of the Chinese Academy of Sciences, No.19 A Yuquan Road, Beijing, 100049, P. R. China.
ChemSusChem. 2022 Oct 10;15(19):e202201068. doi: 10.1002/cssc.202201068. Epub 2022 Aug 26.
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 . In this work, a synergy of photogenerated holes and superoxide radicals that achieved the selective oxidation of glycerol into formic acid over the TiO catalyst was revealed. The charge separation of pristine TiO 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 were controlled to prevent being converted to hydroxyl radicals on TiO by 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.
光催化是将甘油转化为甲酸的一种很有前途的技术，但由于光生自由基（例如羟基自由基）会进一步将甲酸氧化为 CO，因此光催化氧化甘油中的 C-C 键对甲酸的选择性较差。在这项工作中，揭示了光生空穴和超氧自由基之间的协同作用，实现了在 TiO 催化剂上选择性氧化甘油生成甲酸。在氧气的帮助下，改善了原始 TiO 的电荷分离，从而有效地将甘油中的 C-C 键氧化为甲酸。通过控制氧气和水的含量来控制表面活性物质，防止它们在 TiO 上转化为羟基自由基，从而解决了甲酸过氧化的问题，而无需对催化剂进行复杂的修改。机理研究表明，甘油醛和乙二醇醛是生成甲酸的中间体。这项工作为从生物基醇生产作为液体储氢载体的甲酸提供了一种绿色高效的方法。
