EVALUATION OF REACTION KINETICS FOR THE DECOMPOSITION OF TETRAPROPYLAMMONIUM CATIONS IN SILICALITE

Abstract

Thermogravimetric analysis was used to study the decomposition of tetrapropylammonium cations intercalated in silicalite. The decomposition was modelled using temperature-programmed desorption theory (TPD) assuming that the decomposition reaction was first-order in TPA⁺ concentration. The temperature at which the maximum decomposition rate occurred was determined as a function of heating rate. Using these data, values for the activation energy and the reaction rate constant were calculated to be 5l.4kcal/mol and 3.0 × 10¹⁵ min⁻¹, respectively. It was shown that the activation energy was independent of sample weight, indicating that macropore mass transfer limitations were insignificant. It was also determined that activation energy was independent of crystal size indicating that micropore diffusion limitations were also insignificant.