Theory of zeolite catalysis

The reactivity of acidic zeolites to the activation of hydrocarbons is used to illustrate different modeling approaches applied to catalysis. Quantum-chemical calculations of transition-state and ground-state energies can be used to determine elementary rate constants. But to predict overall kinetics, quantum-mechanical studies have to be complemented with statistical methods to compute adsorption isotherms and diffusion constants as a function of micropore occupation. The relatively low turnover frequencies of zeolite-catalyzed reactions compared to superacid-catalyzed reactions are due mainly to high activation energies of the elementary rate constants of the proton-activated reactions. These high values are counteracted by the significant interaction energies of hydrocarbons with the zeolite micro pore wall dominated by van der Waals interactions