Controlled Preparation Of Mesoporous Nickel Catalyst Materials By Adjusting Hole And Studies On Performance In CH₄/CO₂Reforming Reaction

In recent years, It is one of the hot topics that the methane reforming technologywas used to prepare synthesis gas(H2/CO) with extensive utilization. Currently, newreforming technology is CO2/CH4reforming(DRM), i.e. two greenhouse gasesCH4and CO2are conversed into syngas with H2/CO molar ratio as1. CH4/CO2reforming has not been used in industry because the catalyst can not meet the needs ofindustrial production and lose activity easily. A variety of nickel-based catalyst dopedby Y and Zr was designed and prepared, The relationship between structure ofcatalysts and their catalytic activity was discussed by the characterization. Thecatalysts were used in CH4/CO2reforming reaction to investigate their activity. Someconclusions were acquired as follows:1. Ni-based catalysts with different doped Y (0-9%Y-NiO/SBA-15）were preparedby a sol-gel method. Structural properties of the catalysts were studied through avariety of characterization methods. Characterization results ofXRD, TEM, UV, XPS showed that Ni particles were dispersed highly in themesopores of SBA-15. Characterization results of TEM, BET, FT-IR indicated thatmesoporous structure of Y-NiO/SBA-15catalyst was maintained in intact duringDRM reaction. Characterization results of TPR, UV, XPS suggested that there was astrong interaction between nickel particles and support due to the addition of Y2O3.Characterization results of TG, XPS confirmed that the type and amount of depositedcarbon on the catalysts were different. Because of its high specific surface area, highnickel particle dispersion and low carbon deposition,9%Y-NiO/SBA-15exhibitedexcellent catalytic activity.2. Ni-based catalysts with different Zr dopping (0-9%Zr-NiO/SBA-15）wereprepared by a sol-gel method. Structural properties of the catalysts were investigatedthrough a variety of characterization methods. The active metal oxide particles wereuniformly dispersed on the surface of the catalysts due to the promotion action ofzirconium, and combined with the HO-Si bond on the inner surface of support to formNi-O-Si bond, resulted in that the nickel particles dispersed evenly after reduction toavoid sintering and agglomeration of the active metal particles and to promote theactivity and stability of the catalysts. CH4/CO2reforming reaction indicated that9%Zr-NiO/SBA-15had the highest catalytic activity, with methane conversion of89%. 3. The catalytic ability of catalysts is improved not only by a certain promotorbut also by the regulation in the properties of support. In this thesis, novel mesoporousmaterial as support was prepared primarily and the preliminary preparation process, inwhich CMK-3prepared by SBA-15was used as hard template and then metal oxidewith mesoporous framework prepared was probed. The results indicated thatcontrolling calcination temperature was particularly important to the stability instructure. Otherwise, the hole wall collapsed easily during calcination. In addition, thehigh temperature can cause water vapor evaporating quickly and destroy the porestructure. In addition, synthesis of a N3-18-N3surfacant, which can be used as atemplate for the preparation of a novel mesoporous materials, was developedprimarily in this dissertation. Its structure was characterized by NMR, MS and othertechniques.