Catalytic performance and kinetics of Au/γ-Al2O3 catalysts for low-temperature combustion of light a

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.