LaMnO₃-La₂Sn₂O₇ And Pd Monolithic Catalysts For Catalytic Comubustion Of Natural Gas

The technology of catalytic combustion has attracted more and more attention because it can both efficiently utilize natural gas and effectively suppress NOx emissions.However,most of the researches on catalysts of catalytic combustion nowadays are aimed at low concentration methane and there are few research results for natural gas premixed combustion catalysts.Therefore,this paper research on the catalyst which is suitable for high space velocity and high concentration of methane.The reaction condition is as follow:the space velocity is 30000 h-1 and the methane concentration is 4 Vol.%.The catalytic activity was enhanced by the way of addition of modifiers,improvement of preparation method and preferred chosen of carriers.1.Pd/?-Al₂0₃/Ni catalyst and the influence of the addition of Ce/Y on the catalytic performances of it was studied.By using the SEM for the characterization of Pd/y-A12O3/Ni catalysts before and after the addition of Ce/Y and comparing the catalytic activity,the surface morphology and the catalytic activity modified before and after modification were investigated.The specific effect of Ce/Y on the catalytic activity of Pd/y-Al₂0₃/Ni was determined when the concentration of methane is 4 Vol.%.2.The LaMnO₃-La₂Sn₂O₇ catalysts and the influence of different preparation methods and different solvents on the catalytic performance of it was studied.The catalyst was prepared by vacuum loading method for the first time.By comparing with the catalyst prepared by traditional impregnation method,we could determine the optimal preparation method.The active sol was prepared with ethanol and water as solvents respectively.By comparing the catalytic activity and phase composition of the catalysts prepared by two different solvents,the effect of ethanol solvent on the performance of the catalyst could be found.3.The influence of different carriers on Pd and LaMnO₃-La₂Sn₂O₇ catalyst was studied.Monolithic catalysts were prepared with cordierite,alumina and foamed nickel as carriers.By characterization and evaluation of catalysts prepared with different carriers,understanding their surface structure characteristics and obtaining the catalytic activity rules of these catalysts,the optimal carrier could be elected.The catalytic activity of the catalyst was evaluated under different space velocity and the effect of different space velocity was found.