Surface Cobalt Silicate and CoO x Cluster Anchored to SBA-15: Highly Efficient for Cyclohexane Partial Oxidation

• Published in: Catalysis letters Vol. 136; no. 1-2; pp. 20 - 27
• Main Authors: Li, Li, Li, Hui, Jin, Chen, Wang, Xiaochen, Ji, Weijie, Pan, Yi, van der Knaap, Theo, van der Stoel, Roland, Au, C. T
• Format: Journal Article
• Language: English
• Published: Dordrecht Boston : Springer US 01.05.2010; Springer Nature B.V
• Subjects: Catalysis; Catalysts; Chemical industry; Clusters; Cobalt oxides; Continuously stirred tank reactors; Conversion; Cyclohexane; Oxidation; Porosity; Selectivity
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-010-0318-z

The present investigation showed that the surface cobalt silicate and CoO x cluster anchored to SBA-15 are highly efficient heterogeneous catalysts for the cyclohexane partial oxidation with air-like O₂ (20%)-N₂ (80%) mixture as oxidant in the continuously stirred tank reactor at 413 K and 1.0 MPa. Typically, selectivity of 84.6% at cyclohexane conversion of 14.5% can be achieved in a period of 2 h reaction. The performance of Co-catalyst is affected by the nature of Co species introduced to SBA-15. The surface cobalt silicate with higher proportion of “isolated” Co²⁺ sites shows better result than the well dispersed CoO x clusters mainly on the internal surface of SBA-15. Furthermore, different preparation method also influences the porosity of SBA-15 and accessibility to Co sites, which may in turn affect on the reaction performance. Graphical Abstract The surface cobalt silicate and CoOx cluster anchored to SBA-15 are highly efficient for the cyclohexane partial oxidation with air-like O₂(20%)-N₂(80%) mixture as oxidant in the continuously stirred tank reactor at 413 K and 1.0 MPa. Typically, selectivity of 84.6% at cyclohexane conversion of 14.5% can be achieved in a period of 2 h reaction. The catalyst performance is dependent on the nature of Co species introduced to SBA-15. [graphic removed]