Preparation Of Copper And Tin Composites Oxides And Their Catalytic Perpormances For Methane Catalytic Combustion

Catalytic combustion of methane is an effective way to utilize it as an energy source, or to prevent it from polluting the atmosphere. We selected copper oxide that had high catalytic activity at low temperature for CH4 oxidation as active component. Combining tin oxide that had high specific surface areas to promote their catalytic activity and resistance to high temperature.We adopted the sol-gel method, citric acid chelation method and the modified co-precipitation method to prepare series of samples in order to investigate the influence of different preparation process to catalytic properties. The results show that the modified co-precipitation technology behaved well. Furthermore, we optimized every operation of the process and got the best catalytic properties data. They reached the highest activity when CuO were dopped 40%. Its mean particle size was 30nm and its specific surface was 43.51m²/g. Its light-off temperature was 392℃ and conversion-completely temperature was 532 ℃ .The oxidation kinetics of methane over metal oxides catalysts was investigated and we got the kinetic parameters as followed: k = 1.28* 10⁴ , E_a = 9.78* 10⁴ J/mol, α= 1.00,β =-0.74. The slow step of methane oxidation would be postulated as thedissociative chemisorption of the methane on the metal oxides surface followed by its interaction with O₂ adsorbed. The catalysts' surface had sites for both CH₄ and O₂...