of n-heptane over Pt catalysts supported on Al- and Si-promoted Ti[O.sub.2]," Catalysis Today, vol.
Therefore, the only change that takes place is the carboxylic and amidic moieties of the repeat units when they come into contact and taking place into what is known as dehydrocyclization
. The cyclization reaction involves a change in chain architecture as two rings per repeat unit are added to the polymeric chains.
Metallic catalysts have been reported as enhancers to the production of furfural, they may act as Lewis acids promoting the reaction or may stabilize the intermediates in the dehydrocyclization