Catalytic Oxidation of Cyclohexane by Molecular Oxygen Using Polymer Anchored Catalysts

Catalytic Oxidation of Cyclohexane by Molecular Oxygen Using Polymer Anchored Catalysts

Sweta, Shishir Sinha, Prakash Biswas, Shri Chand^*

              Department of Chemical Engineering, Indian Institute of Technology Roorkee, India

Catalytic oxidation is a key technology to transform the naturally available petroleum based feed stocks to more useful organic chemicals such as alcohols, alkenes and carbonyl compounds. The fine chemical industries employ variety of oxidizing reagents such as permanganate and dichromate, however, these reagents are toxic and generate unwanted hazardous by-products. With ever-increasing environmental concerns, much attention has been directed towards the development to replace these antiquated technologies by ‘green technology'.

In many instances, homogeneous catalysis provides powerful solutions, but on an industrial scale the problems related to corrosion and plating out on the reactor wall, handling, recovery and reuse of the catalyst present limitations of these processes. Therefore, research on heterogeneous catalysts becomes important and significant, and in recent past most of the studies have been focused on the use of various supports

Immobilization of catalysts on insoluble or soluble support has gained prominence in recent years. The immobilization of homogeneous catalysts onto polymer supports provides potential for extending the benefits of heterogeneous catalysts to homogeneous catalysts because most polymeric supports are insoluble, inert, nontoxic, nonvolatile, recyclable, enhances the thermal stability and possibility of achieving site isolation, which increases the catalytic activity as well as selectivity. Polymer anchored metal complexes are gaining importance as efficient heterogeneous catalysts in a variety of organic transformations including oxidation and hydrogenation reactions.

In the present work, the oxidation of cyclohexane using polymer anchored Cu(II) and Co(II) complex catalysts in high pressure reactor (Parr reactor, 4843 series) using molecular oxygen has been investigated. The optimal parameters were obtained for the reaction by studying the effect of various reaction parameters. Further, life of the catalyst and recyclability of the support is evaluated for optimal conditions. The kinetic parameters have been evaluated to understand the reaction mechanism. The catalyst recyclability is also studied at optimum reaction conditions.

 Keywords: Oxidation, Polymer support, Selectivity

 

 

 

* Corresponding author. Email: schanfch@iitr.ernet.in; Telephone: +91-1332-285383