| In recent years,steam reforming technology has attracted growing attention as an important method of fuel reforming technologies.Among them,heavy hydrocarbon is often used as a source because of its high energy density,low cost,relatively easy storage and handling.It has good applications in hypersonic vehicle and on-board and on-site fuel cells.Therefore,in this work,we chose n-dodecane as model compound of heavy hydrocarbon to study the performance of Ru/CexZr1-xO2 catalysts prepared by different methods in the steam reforming reaction of n-dodecane.Firstly,we investigated the effects of different ratio of Ce/Zr and reaction conditions?temperature,ration of S/C,liquid hourly space velocity?on Ru-based catalysts by sol-gel method for n-dodecane steam reforming.The results show that Ru/Ce0.75Zr0.25O2 catalyst has high performance.On this basis,the effect of different surfactants on the performance of Ru/Ce0.75Zr0.25O2 catalyst was further studied,and it was found that the activity and stability of the catalyst added with CTAB?Ru/HSA-CZ?was the best.The surface area of Ru/HSA-CZ catalyst is 107.6 m2·g-1,which is ca.three times higher than that prepared through the sol-gel?SG?method(34.3 m2·g-1,Ru/CZ-sg)and ca.40%higher than that without CTAB(76.7 m2·g-1,Ru/CZ-wo).Catalytic steam reforming of n-dodecane,shows the completely conversion of n-dodecane over Ru/HSA-CZ and slightly drops about 6%after 7 h while 81%and 70%were observed for the Ru/CZ-wo and Ru/CZ-sg but with twice?or triple?deactivation rates.In further studies,series of Ru-based catalysts with different Ce content were prepared by evaporation-induced self-assembly method?EISA?.The results show that ordered mesoporous Ce-Zr solid solution can be formed when the content of Ce is low,but the collapse of the ordered mesoporous because of the catalysts undergo the second calcined in the process of impregnating Ru,and ultimately lead to a decrease in the stability of the catalysts.However,the catalyst with a Ce content of 60%has a higher reactivity due to its high oxygen vacancy content and strong redox ability when the content of Ce is high.Proving once again,the strong redox capacity of the catalyst helps to eliminate carbon deposits during the reaction and improve the stability of the catalyst. |
PDF Full Text Request