Catalytic and Photocatalytic Oxidation of Ethylene on Titania-Based Thin-Films

• Published in: Environmental science & technology Vol. 34; no. 24; pp. 5206 - 5210
• Main Authors: Zorn, Michael E, Tompkins, Dean T, Zeltner, Walter A, Anderson, Marc A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15-12-2000
• Subjects: Applied sciences; Catalysts; Exact sciences and technology; Global environmental pollution; Oxidation; Pollution; Studies; Temperature; Mixed catalyst; Photocatalysis; Ethylene; Temperature effect; Supported catalyst; Chemical reaction kinetics; Thin film; Particle; Heterogeneous catalysis; Pollution; Ultraviolet radiation; Zirconium oxide; Decontamination; Platinum; Chemical treatment; Environment; Oxidation; Titanium oxide; Photooxidation; Organic compounds; Photochemical degradation
• DOI: 10.1021/es991250m
• EISSN: 1520-5851
• ISSN: 0013-936X

The effect of reaction temperature on the catalytic and photocatalytic oxidation of ethylene on unplatinized and platinized versions of a TiO2/ZrO2 mixed-oxide thin-film catalyst is presented in this study. Ethylene conversion data collected using a recirculating tubular reactor are analyzed using a half order model of reaction kinetics. When operated in the presence of UV, both catalysts exhibit significant (95% confidence) increases in the reaction rate constant at 70 °C compared to 30 °Cno difference is observed between unplatinized and platinized versions at these two temperatures. However, only the platinized catalyst performs better at 107 °C compared to its performance at 70 °C. Also, at 107 °C in the presence of UV, the reaction rate constant obtained for the platinized catalyst is a factor of 2 larger than that obtained using the unplatinized catalyst. Catalytic reaction rate constants for the platinized catalyst were 1 (107 °C) to 2 (70 °C) orders of magnitude lower than corresponding photocatalytic reaction rate constants. Comparisons between the thin-film catalysts studied here and a previously reported particulate catalyst show a fundamental difference in photocatalytic behavior, mainly due to insufficient utilization of the internal bulk of the particulate catalyst.