Preparation of carbon-supported Pt catalysts covered with microporous silica layers using organosilanes: Sintering resistance and superior catalytic performance for cyclohexane dehydrogenation

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• 作者：Keizo Nakagawa^a ; ^b ; ^c ; ^{knakagaw@chem.tokushima-u.ac.jp} ; Tetsuya Okayama^c ; Yusuke Tanimoto^c ; Ken-Ichiro Sotowa^a ; ^b ; ^c ; Shigeru Sugiyama^a ; ^b ; ^c ; Toshihiro Moriga^a ; ^b ; ^c ; Sakae Takenaka^d ; Masahiro Kishida^d
• 关键词：Carbon-supported Pt catalyst ; Silica coating ; Microporous silica layer ; Sintering resistance ; Cyclohexane dehydrogenation
• 刊名：Applied Catalysis A ; General
• 出版年：2012
• 期刊代码：4_0926860x
• 类别：ch
• 出版时间：29 March, 2012
• 卷：419-420
• 期：Complete
• 页码：13-21
• 文件大小：1588 K

摘要

Carbon black-supported Pt metal particles (Pt/CB) were covered with microporous silica layers using different organosilanes like methyltriethoxysilane (MTES) (SiO₂(MTES)/Pt/CB) and phenyltriethoxysilane (PhTES) (SiO₂(PhTES)/Pt/CB). Pt metal particles in Pt/CB covered with microporous silica layers were stable at high temperature up to 973 K in a hydrogen atmosphere, because the microporous silica layers that wrapped around the Pt metal particles essentially prevent particle sintering. Methyl or phenyl groups were introduced into the silica layers that covered the Pt metal particles using MTES or PhTES hydrolysis. Micropores were formed in the silica layers effectively after thermal treatment at 973 K. The microporous silica-coated Pt catalysts were used as model catalysts for the dehydrogenation of cyclohexane. The microporous silica-coated Pt catalysts with thermal treatment at 973 K exhibited a higher conversion of cyclohexane compared with Pt/CB. Especially, the SiO₂(PhTES)/Pt/CB catalysts showed relatively higher conversion of cyclohexane compared with the other silica-coated Pt catalysts even when the SiO₂ loading was high. Microporous silica layers with a larger micropore volume promoted the diffusion of cyclohexane during the catalytic reaction.