0000000000587842
AUTHOR
C Márquezálvarez
Visible-light-induced oxidation of trans-ferulic acid by TiO2 photocatalysis
Abstract The oxidation of trans-ferulic acid (C10H10O4) in aqueous TiO2 dispersion occurs via the formation of a charge-transfer complex on the TiO2 surface that is able to absorb visible light (λ ⩾ 400 nm). The main product is CO2, whereas secondary oxidation products are organic species such as vanillin, caffeic acid, homovanillic acid, and vanillylmandelic acid. Oxidation through the formation of a charge-transfer complex occurs only in the presence of specific TiO2 samples. Experiments in the absence of oxygen, in the presence of bromate ions and by using a phosphate-modified TiO2, have been carried out for investigating the reaction mechanism. In order to study the interaction between …
Photocatalytic Oxidation of Aromatic Alcohols to Aldehydes in Aqueous Suspension of Home Prepared Titanium Dioxide. 1 Selectivity Enhancement by aliphatic alcohols
Oxygenated aqueous suspensions of home-prepared (HP) and commercial TiO2 catalysts were used in a batch photoreactor for carrying out the oxidation of benzyl alcohol (BA) and 4-methoxybenzyl alcohol (MBA) under different operative conditions. HP catalysts were synthesized from TiCl4 and underwent a hydrolysis treatment of different times under mild conditions. The textural characterization of catalysts was carried out with XRD, SEM observations, BET surface area and porosity measurements. For both alcohols the main oxidation products were the corresponding aromatic aldehydes and CO2. The HP catalysts exhibited selectivity values towards the aldehyde production up to 28% (BA conversion: 50%)…