CeO2 MODIFIED LUFFA-STRUCTURED SiC AND THEIR APPLICATION IN Co3O4-CATALYZED CO OXIDATION

• Main Authors: Chien-Hung Lien, 連健宏
• Other Authors: Yung-Jen Lin
• Format: Others
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/95618000492509511756

碩士 === 大同大學 === 材料工程學系(所) === 98 === Natural luffa was converted into silicon carbide and used as catalyst supports. The luffa-structured SiC was impregnated with cobalt nitrate solution and heat treated to form Co3O4/SiC supported catalysts. In order to enhance the catalytic activity, CeO2 was also coated on the surface of SiC before loading with Co3O4 to form Co3O4/CeO2/SiC supported catalyst. To characterize the catalyst systems, Scanning electron microscopy (SEM was used for microstructural investigation, powder x-ray diffractometry (XRD) for crystal identification and CO oxidation efficiency for Co3O4 catalyst performance. Results showed when the weight ratio of Co3O4 to SiC was 15:100, the supported catalyst had its best activity (lowest T50). But when Co3O4 increased and the Co3O4 -to-SiC ratio reached 25: 100, catalyst activity decreased due to Co3O4 particle coalescence during heat treatment. The optimal temperature for catalyst heat treatment was 500℃. Higher heat treatment temperature caused sintering of Co3O4, which decreased its catalytic activity. Surface modification of SiC with CeO2 could effectively improve Co3O4 performance. This is supposed to be attributed to the good oxygen storage capacity of CeO2. In Co3O4/CeO2/SiC supported catalysts, the best combination was achieved when Co3O4 , CeO2 and SiC weight ratio was 15: 25:100. Such supported catalyst had its best CO oxidation performance with T50 =141℃.