A kinetic analysis of ethane hydrogenolysis has been carried out on Pt SiO2 and PtFe SiO2 catalysts with a wide range of concentration of the components, and with an excess of ethane. With the help of the theory of stationary reactions on heterogeneous surfaces, kinetic equations were obtained describing the reaction rate both in excess hydrogen and excess ethane which are in full agreement with the experimental observations. On platinum in excess hydrogen the rate of hydrogenolysis is determined by the CC bond rupture of ethane adsorbed in a mildly dissociated C2Hx form, while in excess hydrocarbon it is determined by the CC bond rupture of ethane adsorbed in the deeply dissociated form of C2H2. The reaction rate passes through a maximum vs ethane pressure at constant hydrogen pressure and vice versa. The formal reaction order in hydrogen and hydrocarbon can be either positive or negative depending on the conditions; the formal power-rate equations may be considered as approximations of the more complicated equations presented in this work.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry