(629m) 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