核壳材料Co3O4@SiO2催化环己基过氧化氢分解

环己基过氧化氢(CHHP)分解是环己烷无催化氧化工艺制备环己醇和环己酮的重要反应步骤.本研究以Co3O4纳米颗粒为内核,十六烷基三甲基溴化铵(CTAB)为模板剂,正硅酸四乙酯(TEOS)为硅源,采用模板法制备了核壳结构材料Co3O4@SiO2.考察了SiO2壳层制备条件:乙醇和水的比例、CTAB的浓度和TEOS的用量对...

Decomposition of Cyclohexyl Hydroperoxide Catalyzed by Core-shell Material Co3O4@SiO2

Decomposition of cyclohexyl hydroperoxide(CHHP)is an important step in the preparation of cyclohexanol and cyclohexanone by non-catalytic oxidation of cyclohexane.Using Co₃O₄ nanoparticles as the core,cetyltrimethylammol/lonium bromide(CTAB)as the template and tetraethyl orthosilicate(TEOS)as the silicon source,the core-shell structure material Co₃O₄@SiO₂ was synthesized by template method.The effects of the preparation conditions for SiO₂ shells on the structure of core-shell material were investigated,such as the ratio of ethanol to water,the concentration of CTAB and the amount of TEOS.Textural properties of the materials were characterized by different techniques.Meanwhile,the catalytic performance and stability of the materials were evaluated on the decomposition reaction of CHHP.All results showed that the materials with thin shell and high porosity exhibited a preferable catalytic performance,and the conversion of CHHP was 81.68%and the selectivity of cyclohexanol and cyclohexanone was 70.60%and 34.06%,respectively.This core-shell structure could protect the activity of the core Co₃O₄ and significantly decrease the loss of cobalt element.However,there existed different degree of the fragmentation of SiO₂ shell in the recycling process of Co₃O₄@SiO₂ samples.