Kinetic effects and oxidation pathways of sacrificial electron donors on the example of the photocatalytic reduction of molecular oxygen to hydrogen peroxide over illuminated titanium dioxide

B. O. Burek, J. Timm, D. W. Bahnemann, J. Z. Bloh

Catal. Today, 335 (2019), 354-364, doi:10.1016/j.cattod.2018.12.044

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Abstract

Sacrificial electron donors are frequently used in photocatalytic reactions to enhance the performance of the reaction, typically short-chain alcohols as well as their respective aldehydes and acids are used. This study focuses on the differences between the individual electron donors regarding their oxidation rates, mechanistic pathways, the influence of the intermediates and their direct impact on the H₂O₂ generation. The individual H₂O₂ formation rates of 16 different electron donors, photonic and faradaic efficiencies for H₂O₂ production are carefully discussed. Furthermore, a new multi-reaction pathway for t-butanol oxidation is postulated and critically examined.

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