Studies on surface impregnation combustion method to prepare supported Co/SiO₂ catalysts and its application for Fischer-Tropsch synthesis

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• 作者：Lei Shi ; Yuzhou Jin ; Chuang Xing ; Chunyang Zeng ; Tokimasa Kawabata ; Kouji Imai ; Kenji Matsuda ; Yisheng Tan ; Noritatsu Tsubaki
• 关键词：Surface impregnation combustion ; Metallic catalysts ; Co/SiO2 ; Fischer&ndash ; Tropsch synthesis
• 刊名：Applied Catalysis A: General
• 出版年：2012
• 出版时间：5 September, 2012
• 年：2012
• 卷：435-436
• 期：Complete
• 页码：217-224
• 全文大小：752 K

文摘

A series of supported Co/SiO₂ catalysts were prepared by surface impregnation combustion method using cobalt nitrates and citric acid, and the precursors were burnt in different atmospheres. The effects of different calcination atmospheres on the properties of the supported Co/SiO₂ catalysts were systemically studied by TG-DTA, XRD, Raman spectrum, TPR, in situ FTIR, TEM, BET and H₂-chemisorption techniques. The burnt catalyst C_{argon-air-reduction} which was first burnt in argon and then oxidized in air had about 10 nm Co₃O₄ crystalline size, much smaller than that which was directly burnt in air (Co₃O₄ size: about 15 nm) and that prepared by conventional impregnation method (Co₃O₄ size: about 32 nm) using cobalt nitrate as impregnating solution. Characterizations and FTS results of two other references using different organic cobalt salt aqueous (cobalt acetate and cobalt citrate) as impregnating solution were also added in the supporting information. Comparing with our previously reported C_argon catalyst directly burnt in the argon atmosphere without further reduction, the influence from surface amorphous carbon and carbonic residues was completely eliminated. The activity of the burnt catalyst C_{argon-air-reduction} prepared by surface impregnation method was threefold higher than that of the reference C_N-reduction prepared by conventional incipient-wetness impregnation method. The surface impregnation combustion method described herein was promising to prepare highly dispersed supported metallic catalysts with smaller particle sizes.