Cobalt molybdenum oxide catalysts for selective oxidation of cyclohexane

Ashish P. Unnarkat, Tam Sridhar, Huanting Wang, Sanjay Mahajani, Akkihebbal K. Suresh

Research output: Contribution to journalArticleResearchpeer-review

18 Citations (Scopus)


Oxidation of cyclohexane has been carried out using molecular oxygen over cobalt molybdenum oxide (CoMoO4) catalysts in solvent free conditions. The catalysts were prepared using citrate method with three different molar ratios of Co:Mo, 1:1, 1:2, and 2:1 along with individual oxides for comparative studies. While all the catalysts showed significant activity and selectivity, CoMoO4 with 1:1 ratio showed the best performance compared to the others with a conversion of 7.38%, with selectivity to cyclohexanol and cyclohexanone (KA oil) of 94.3%, in 1 h. The performance of the catalyst, has been studied as a function of oxygen pressure, reaction temperature, and catalyst loading. It was observed that the catalyst deactivates during the course of the reaction. The reasons for deactivation and methods for restoring the activity have been studied. A kinetic model is presented that captures the complex kinetics and matches well with the experimental data.

Original languageEnglish
Pages (from-to)4384-4402
Number of pages19
JournalAIChE Journal
Issue number12
Publication statusPublished - 1 Dec 2016


  • catalyst deactivation
  • cobalt molybdenum oxide
  • cyclohexane oxidation
  • KA-oil
  • kinetic model

Cite this