Synthesis of bisphenol-A: Comparison of efficacy of ion exchange resin catalysts vis-a-vis heteropolyacid supported on clay and kinetic modelling

The production of bisphenol-A from phenol and acetone over ion exchange resins has been practised industrially, with the selectivity to the product largely depending on the type of catalyst and reaction conditions. This study reports the use of a novel catalyst based on heteropolyacid supported on clay, particularly dodecatungstophosphoric acid (DTP) supported on K-10 clay and its comparison with commercially available resins such as Amberlyst-15, Amberlyst-31 and Amberlyst-XE-717p. DTP/K-10 is an efficient and re-usable catalyst which could be employed at higher temperatures. This catalyst is characterised by XRD, BET, SEM, FTIR and the cation exchange capacity (CEC) has been determined. The kinetics of the reaction with DTP/K-10 have shown interesting features among which the formation of intermediate isopropenyl phenol was found to be the rate determining step with the Eley-Rideal type of mechanism.