物理化学学报 >> 2008, Vol. 24 >> Issue (01): 171-175.doi: 10.3866/PKU.WHXB20080131

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高比表面SiC的合成及其在CO氧化反应中的应用

詹瑛瑛; 蔡国辉; 郑勇; 沈小女; 郑瑛; 魏可镁   

  1. 福州大学化肥催化剂国家工程研究中心, 福州 350002; 福建师范大学化学与材料学院, 福州 350007
  • 收稿日期:2007-08-26 修回日期:2007-09-11 发布日期:2008-01-05
  • 通讯作者: 魏可镁 E-mail:wei-kemei@163.com

Synthesis of High Surface Area Silicon Carbide and Its Application in CO Oxidation Reaction

ZHAN Ying-Ying; CAI Guo-Hui; ZHENG Yong; SHEN Xiao-Nv; ZHENG Ying; WEI Ke-Mei   

  1. National Engineering Research Center of Chemical Fertilizer Catalyst at Fuzhou University, Fuzhou 350002, P. R. China; College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, P. R. China
  • Received:2007-08-26 Revised:2007-09-11 Published:2008-01-05
  • Contact: WEI Ke-Mei E-mail:wei-kemei@163.com

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摘要： 采用蔗糖为碳源, 正硅酸乙酯(TEOS)为硅源, 分别以草酸、硝酸铁、硝酸镍为催化剂, 用溶胶-凝胶法制备碳化硅前驱体, 考察了制备过程中催化剂的种类以及反应温度和时间对凝胶形成的影响. 发现以硝酸铁为催化剂最有利于凝胶的形成, 碳/硅物质的量比为4的前驱体在氩气气氛1350 ℃下加热10 h, 碳热还原反应趋于完成. 以该条件下合成的多孔碳化硅(比表面积133 m2·g-1)作为催化剂载体, 通过等量浸渍法获得Pt/SiC催化剂, 将其应用于一氧化碳氧化的模型反应中. 研究结果表明该催化剂有较好的催化活性和稳定性. 引入镍助剂的PtNi/SiC催化剂能进一步提高一氧化碳催化氧化反应的活性.

关键词: 溶胶-凝胶, 碳化硅, 高比表面, CO氧化, 载体

Abstract: A sol-gel process was employed to prepare SiC precursors, using tetraethyl orthosilicate (TEOS) and sucrose as raw materials. And oxalic acid, ferric nitrate, and nickel nitrate were added respectively as catalyst for hydrolysis and polymeration reactions. The effects of catalyst, reaction temperature, and reaction time on the gel formation were studied. The results showed that ferric nitrate was optimal for gel formation. SiC of 133 m2·g-1 was obtained by further carbonthermal reduction of the xerogel from the sol-gel system involved ferric nitrate, at 1350 ℃ in an Ar flow for 10 h. Such SiC was then used as catalyst support for CO oxidation. Wet impregnation method was adopted to obtain Pt/SiC catalyst. The as-prepared Pt/SiC catalyst showed good activity and stability for CO oxidation. It was also found that its performance could be improved significantly with the synergistic action of Ni promoter.

Key words: Sol-gel, Silicon carbide, High surface area, CO oxidation, Support