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URN etd-0904108-170427 Statistics This thesis had been viewed 4113 times. Download 1806 times. Author Hsin-Hsien Chen Author's Email Address email@example.com Department Materials Engineering Year 2007 Semester 2 Degree Master Type of Document Master's Thesis Language zh-TW.Big5 Chinese Page Count 84 Title SiC Based Catalyst Supports Fabricated from Luffa Cylindrica and Their Application in Ni-catalyzed CO Oxidation Keyword catalysts Luffa Cylindrica SiC SiC Luffa Cylindrica catalysts Abstract The purpose of this study is to compare the effects of three supports for Ni catalyst: SiC prepared from Luffa Cylindrica,γ-Al2O3 prepared by the sol-gel method and SiC coated with γ-Al2O3. The supports were dripped with different concentration Ni(NO3)2 by incipient wetness impregnation method to produce supported Ni catalysts. The Luffa Cylindrica was first transformed into charcoal by carbonization in N2 atmosphere. Proper proportion of Si was then reacted with porous charcoal to form porous SiC with the structure of Luffa Cylindrica. The SiC was immersed in Al(OH)3 prepared by sol-gol method, and then dried and calcined. SiC support withγ-Al2O3 coating was formed. Supported Ni catalysts was prepared by dripping Ni(NO3)2 solution of different concentration into the supports (impregnation method). After dried, calcined and reduced in H2/N2 atmosphere, supported Ni catalysts were obtained.
The results pointed out that the support of SiC with 15wt% Ni had Ni well dispersed. Ni particles begun to agglomerate when Ni was 30 wt％. The agglomeration was significant when Ni was 40 wt%. The agglomeration reduced the activity of Ni. Ni catalysts supported onγAl2O3-SiC or γAl2O3 did not agglomerate, and the catalysts activity increased monotonically with Ni content.
After SiC was coated with γ-Al2O3, specific surface area increased ( from 16 m2/g to 131 m2/g), and partial large pores shrank, and some small pores (~1 μm) were closed. This resulted in decreasing Ni content into supports. Thus, when comparing the different supports with 30 wt％ Ni, and Ni/ SiC catalyst activity was better than Ni/γAl2O3-SiC.
Comparing CO oxidation reaction activity of different supports with different Ni content, it showed that catalyst Ni/γAl2O3- SiC with 60 wt％ Ni had the highest catalytic activity( T50 = 265 ℃). For Ni/SiC,the highest activity occurred when Ni was 30％( T50 =272 ℃ ).
Advisor Committee Yung-Jen Lin - advisor
Jim-Jyh Shyu - co-chair
Rong-Chi Wang - co-chair
Shu-Hua Chien - co-chair
Files Date of Defense 2008-07-30 Date of Submission 2008-09-04