Photocatalytic Oxidation and Decomposition of Acetic Acid over TiO2, TS-1 and Ti-MCM-41 Catalysts
Transient reaction of adsorbed monolayer of acetic acid was used to compare the photocatalytic properties of TiO2 (Degussa P-25), titanium silicalite (TS-1) and Ti-MCM-41. TS-1 and Ti-MCM-41 catalysts with Si/Ti ratio of 50 were prepared by in-situ crystallization. The catalysts were characterized using XRD and UV-DRS. During photocatalytic oxidation (PCO), CO2 and HCHO were formed on P-25 TiO2, whereas CO2 and CH4 formed on TS-1 and Ti-MCM-41. Acetic acid decomposed photocatalytically on P-25 TiO2 to form CO2, CH4 and C2H6. On the contrary, CO2 and CH4 were formed on TS-1 and Ti-MCM-41 during photocatalytic decomposition (PCD). The rates of product formation during PCD were lower than PCO. The TS-1 and Ti- MCM-41 catalysts were less active per gram of catalyst. However, the TS-1 and Ti-MCM-41 catalysts had much higher adsorption capacities for organics. Therefore, it seems that the TS-1 and Ti-MCM-41 catalysts have some advantages in applications to PCO of organic comtaminants under conditions where the organic concentrations vary widely.
Hyung Sun Kim, Yu Bao Li and Soo Wohn Lee
J. H. Park et al., "Photocatalytic Oxidation and Decomposition of Acetic Acid over TiO2, TS-1 and Ti-MCM-41 Catalysts", Materials Science Forum, Vols. 510-511, pp. 34-37, 2006