Carbonylation of ethanol using homogeneous iridium complex catalyst: a kinetic study

Abstract

The kinetics of carbonylation of ethanol using Ir complex catalyst and hydroiodic acid (HI) as a promoter has been studied. The effect of IrCl₃ . 3H₂O, HI and ethanol concentrations and the partial pressure of carbon monoxide on the rate of carbonylation has been studied over a temperature range of 443-473 K. The rate of carbonylation was found to be 0.71 and 0.62 order with respect to ethanol and catalyst concentrations respectively, while a zero-order dependence with CO (above 38 atm) was observed. With an increase in HI concentration the rate first increased and then decreased indicating a maximum. A rate equation has been proposed and kinetic parameters evaluated. The activation energy of the reaction was found to be 25.53 kcal mol^-1.