Photooxidation of triethylamine (TEA) in the presence of O2, N2, and H2O over titanium oxide (TiO2) was investigated using a flat plate reactor. TEA was photocatalytically oxidized to CO2 and some by-products on TiO2 thin film catalysts. The intrinsic oxidation rate of the reaction was determined and was dependent on TEA concentration, humidity level, and light intensity. Photocatalytic deactivation was observed in these reactions. Fourier transform infrared (FTIR) and temperature-programmed desorption with a mass spectrometer as a detector (TPD-MS) were used to characterize the surface of the catalyst and study the deactivation mechanism. FTIR and TPD-MS results suggest that accumulation of carboxylic acid species, -N-N=O, and some other carbonaceous species occurred during the reaction. These by-product species or intermediates were chemisorbed on the catalyst surface. They were stable under reaction conditions and might be responsible for deactivation of TiO2 by either poisoning the active sites directly or blocking the adsorption of TEA on the catalyst surface.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry