SiO supported Ce-Co mixed oxide catalyzed selective allylic oxidation of cyclohexene

• Published in: New journal of chemistry 2024-01, Vol.48 (5), p.1932-1942
• Main Authors: Sitaramulu, Palli, Nazeer, Silligandla, Yogendra, Kamma, Prasad, Aratikumari Suresh, Chandrashekar, Pendem, Rao, Tumula Venkateshwar
• Format: Article
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj04852g

In this study, silica supported ceria, ceria-cobalt mixed oxide, silica supported ceria-cobalt mixed oxide, pure ceria, and cobalt oxide (CeO 2 /SiO 2 , CeO 2 -Co 3 O 4 and CeO 2 -Co 3 O 4 /SiO 2 , CeO 2 , and Co 3 O 4 ) catalysts were prepared and evaluated for selective oxidation of cyclohexene to allylic products ( i.e. , 2-cyclohexen-1-ol and 2-cyclohexen-1-one). The above catalysts were prepared through co-precipitation and deposition co-precipitation methods. Various physical characterization techniques namely XRD analysis, BET studies, Raman studies, FE-SEM analysis, XPS analysis, and NH 3 -TPD analysis were used to investigate the structure, morphology, surface area and the textural properties of the catalysts. The results have confirmed that the Co doped into the ceria and dispersed on silica leads to enhanced surface area, oxygen vacancies and the redox behavior of the catalyst. Among all these catalysts, the silica supported cobalt doped ceria catalyst CeO 2 -Co 3 O 4 /SiO 2 showed superior catalytic activity towards cyclohexene oxidation reactions. Conversion of cyclohexene and selectivity for allylic products depend on various reaction parameters namely the reaction temperature, reaction time, amount of the catalyst, cyclohexene/oxidant ratios, and nature of the solvent. CeO 2 -Co 3 O 4 /SiO 2 catalyst exhibited superior catalytic activity compared to pure oxides for cyclohexene oxidation with 94% conversion and 90% of selectivity towards allylic products.