Photocatalytic oxidation of gaseous DMF using thin film TiO2 photocatalyst

• Published in: Chemosphere (Oxford) Vol. 58; no. 8; pp. 1071 - 1078
• Main Authors: CHANG, Chiu-Ping, CHEN, Jong-Nan, LU, Ming-Chun, YANG, He-Yuan
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 01.02.2005
• Subjects: Air Pollution, Indoor - prevention & control; Applied sciences; Atmospheric pollution; Catalysis; Coloring Agents - chemistry; Combustion and energy production; Dimethylformamide - chemistry; Exact sciences and technology; Oxidation-Reduction; Photochemistry; Pollution; Prevention and purification methods; Textile Industry; Titanium - chemistry; Ultraviolet Rays; Catalyst regeneration; Deactivation; N,N'-dimethylformamide; Photocatalysis; Chemical reaction kinetics; Thin film; Heterogeneous catalysis; Organic solvent; Regeneration; Ultraviolet radiation; N,N-Dimethylformamide; Leather industry; Organic amide; Physicochemical purification; Oxidation; Titanium oxide; Catalyst activity; Flue gas purification; Titanium dioxide; Textile industry; Photochemical degradation; Heterogeneous reaction
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2004.09.072

The heterogeneous photocatalytic oxidation of gaseous N,N'-dimethylformamide (DMF) widely used in the manufacture of synthetic leather and synthetic textile was investigated. The experiments were carried out in a plug flow annular photoreactor coated with Degussa P-25 TiO2. The oxidation rate was dependent on DMF concentration, reaction temperature, water vapor, and oxygen content. Photocatalytic deactivation was observed in these reactions. The Levenspiel deactivation kinetic model was used to describe the decay of catalyst activity. Fourier transform infrared (FTIR) was used to characterize the surface and the deactivation mechanism of the photocatalyst. Results revealed that carbonylic acids, aldehydes, amines, carbonate and nitrate were adsorbed on the TiO2 surface during the photocatalytic reaction. The ions, NH4+ and NO3-, causing the deactivation of catalysts were detected on the TiO2 surface. Several treatment processes were applied to find a suitable procedure for the regeneration of catalytic activity. Among these procedures, the best one was found to be the H2O2/UV process.