Photothermal synergistic engineering of CeO2 and Au co-modified VO2 for efficient and selective oxidation of aromatic alcohols

This work successfully constructs a novel 10% AVO/CeO 2 composite displaying a 2726.92 umol/g/h yield of aromatic aldehyde under mild conditions, elucidates the corresponding photothermal synergistic mechanism, and provides an alternative possibility for the industrialization of photothermal catalytic aromatic alcohol oxidation. • The yield of the aromatic aldehyde on 10% AVO/CeO 2 catalyst is up to 2.727 mmol/g/h. • Photoexcited h + and •O 2 – were confirmed to be the main active species. • The intermediates and products were dynamically monitored by in-situ DRIFTS. • A possible mechanism for enhancing photothermal activity was proposed. The reactions of selective aromatic alcohol oxidation are of great significance to basic research and industrial production, yet still facing some challenges, such as harsh reaction conditions, complex reaction systems and environmental pollution. Herein, Au/VO 2 /CeO 2 (AVO/CeO 2 ), a novel photothermal catalyst was designed for the selective oxidation of aromatic alcohols to aromatic aldehydes. Under atmospheric pressure, the optimized 10% A(0.1%)VO/CeO 2 (0.1% Au/VO 2 denoted as A(0.1%)VO) displays a yield up to 2726.92 μmol/g/h and a selectivity over 99%. A possible photothermal synergistic catalysis mechanism was also proposed on the base of the physical and chemical characterizations and theoretical calculation results. In the thermal cycle process following Mars van Krevelen mechanism, the V 5+ and Ce 4+ oxidized aromatic alcohols into aromatic aldehydes, and the generated V 4+ and Ce 3+ were oxidized back to V 5+ and Ce 4+ by the adsorbed oxygen. In the photocatalytic process, the adsorbed oxygen combined with the photogenerated e – derived from CeO 2 to generate •O 2 – and separated the photogenerated charge effectively. Together with the adsorbed oxygen, •O 2 – and h + participated in oxidizing V 4+ , which further enhanced the aromatic alcohols oxidation. Moreover, the introduced Au nanoparticles further accelerated the separation and transport of photogenerated charge, thus improving the photooxidation performance.