Ethanol Steam Reforming on Ni Catalysts Supported by Ordered Mesoporous Materials

• Main Authors: Kung,Hsuan-Ying, 龔萱穎
• Other Authors: Wang,Chen-Bin
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/55101123553998318369

碩士 === 國防大學理工學院 === 化學工程碩士班 === 101 === Use of ordered mesoporous materials (OMMs) as supports for the supported Ni-based catalysts were investigated in the hydrogen production via stream reforming of ethanol (SRE). In order to study the supports effect, inorganic (SBA-15) and organic (CMK-3 and ordered mesoporous carbon, OMC) mesoporous materials were used. Supported catalysts were prepared by impregnation method from Ni(NO3)2•6H2O with SBA-15, CMK-3 and OMC, which denoted as Ni/SBA-15, Ni/CMK-3 and Ni/OMC, respectively. The structural order and textural properties of the Ni/OMM catalysts were studied by X-ray powder diffraction (XRD), nitrogen sorption (N2-BET) and transmission electron microscopy (TEM), which showed the Ni-based catalysts with hexagonally ordered mesoporous structure, small metal particle size, highly metal dispersion and high surface area. SRE was tested in a fixed-bed reactor under an H2O/EtOH molar ratio of 13 and 22,000 h-1 GHSV. High hydrogen selectivity and ethanol conversion were obtained with all Ni-based catalysts at high temperature. At 500 oC, the highest hydrogen yield up to 5.79 was obtained. Particularly, the Ni/CMK-3 catalyst was able to completely convert ethanol at 250 oC. The products of H2 (71 %), CO2 (19 %), CH4 (9 %) and negligible CO were produced at 450 oC. The coke deposition of spent Ni-based catalysts had also characterized by TEM, Raman spectroscopy, element analysis (EA). A lower amount of carbon nanotubes and carbon nanofibers were observed in Ni/CMK-3 catalyst. Moreover, the catalytic stability maintained over 400 h with high performance at 450 oC. The preliminary results indicated that the OMMs used could enhance the metal dispersion to inhibit sintering of metal at high reaction temperature.