Effects Of Preparation Method On The Performance Of Ni/SBA-15 For Dry Reforming Of Methane

Dry reforming of methane(DRM)has attracted increasing attention in recent years due to the fact that it utilizes two major greenhouse gases(CH4 and CO2),which can contribute to reduce global warming.During DRM reaction,these two gases could be converted into valuable synthesis gases(H2 and CO).DRM reaction becomes industrially advantageous because of lower H2/CO ratio,which is more suitable for synthesis of oxo-and Fischer-Tropsch synthesis processes.However,the main problem is the rapid deactivation of the catalysts.Considering economic feasibility and catalytic activity,the Ni-based catalyst is regarded as one of the most promising candidates for practical application.In this paper,Ni-SBA-15 catalysts are synthesised by impregnation method and the removal of support template is prepared by the ethanol extraction method.Compared with the high temperature calcination method,extraction method is process simple and saving energy.Compared the Ni loading different support with two template removal method for dry reforming of methane,we found that Ni-SBA-15 shows superior catalytic activity and stability after reacting at 700℃ for 50 h,and the carbon deposition and metal sintering of the Ni-SBA-15 in DRM reaction can be significantly inhibited by the high dispersion of nickel species and strong interaction between the Ni species and mesoporous support.Template extraction method is a mild treatment condition and avoids the dehydroxylation and structure shrinkage in thetemplate removal step,thereby provides partsurface silanol groups for the dispersion of the Ni and promotes catalytic performance of Ni-SBA-15.Subsequently.SBA-15,KIT-6 and MCM-41 were synthesized following the previously reported procedures,except the absence of calcination.Ni supported various ordered mesoporous silica materials(SBA-15,KIT-6 and MCM-41)catalysts were prepared by solid-state grinding method and applied to the dry reforming of methane(DRM).Compared with traditional impregnation method,solid-state grinding method is a simple and efficient method to drive active metal components into the channels of mesoporous silica materials.The solid-state grinding method can not only enhance the interaction between the active species and the supports,but also improve the dispersion of the active component on the mesoporous silica materials.After reacting at 700 ℃ for 100 h or 800℃ for 50 h.Ni-SBA-15 prepared by solid-state grinding method shows best catalytic activity and stability among all the catalysts.The average Ni particles size is 3.2 nm for the reduced and Ni-SBA-15.However,the average Ni particles size is 4.3 nm for endurance-tested after long time life reaction.The Ni-SBA-15 presented excellent resistance to the carbon deposition,and the carbon deposition decreased in the order of Ni-MCM-41(38.8%)>Ni-KIT-6(8.1%)>Ni-SBA-15(6.3%)after reacting at 700 ℃ for 100 h.