Catalytic performance and kinetics of Au/γ-Al2O3 catalysts for
low-temperature combustion of light alcohols
low-temperature combustion of light alcohols
(1. School of Chemistry and Chemical Engineering,
Key Laboratory of Theoretical Chemistry and Molecular Simulation, Ministry of Education,
Hunan University of Science and Technology, Xiangtan 411201, China;
2. Valiant Fine Chemicals Co. Ltd., Yantai 264006, China)
Key Laboratory of Theoretical Chemistry and Molecular Simulation, Ministry of Education,
Hunan University of Science and Technology, Xiangtan 411201, China;
2. Valiant Fine Chemicals Co. Ltd., Yantai 264006, China)
Abstract: Au/γ-Al2O3 catalysts were prepared by deposition-precipitation method for the catalytic combustion of low concentration alcohol streams (methanol, ethanol, iso-propanol and n-propanol). The catalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD) and energy dispersive X-ray micro analysis (EDS) techniques. The XPS results showed that there was only Au0 on the surface of catalysts. The XRD patterns showed that Au was presumably highly dispersed over γ-Al2O3. The temperatures for complete conversion of methanol, ethanol, iso-propanol and n-propanol with concentration of 2.0 g/m3 were 60, 155, 170 and 137 ℃, respectively, but they were completely mineralized into CO2 and H2O at 60, 220, 260 and 217 ℃ respectively over the optimized catalyst. The activity of the catalyst was stable in 130 h. The kinetics for the catalytic methanol elimination followed quasi-first order reaction expressed as r=0.652 8c0+0.084 2. The value of apparent activation energy is 54.7 kJ/mol in the range of reaction temperature.
Key words: gold; supported catalyst; light alcohols; low-temperature catalytic combustion; kinetics