06/02194 Kinetics of CH4, H2S and SO2 oxidation on precious metal catalysts under stagnation point flow conditions

Abstract

A new methodology which combines reactor experiments and numerical modelling to derive kinetic rates of solid-gas heterogeneous reactions in a stagnation point flow reactor (SPFR) is developed and used to investigate the effects of small concentrations of H 2 S and SO 2 on the lean respectively. Repeated use of the washcoated catalyst add the effect of pore opening given rise to a change in the pre-exponential factor from 7.410 5 cm s -1 to 1.110 9 cm s -1 for Pt. The high temperature activity behaviour of Pt in presence of sulphur species in the feed was however superior to that of Pd, due to the changing nature of the active site in CH 4 oxidation (PdO/Pd), as is consistent with the literature based on other type of reactor studies. Methane combustion was enhanced by both H 2 S and SO 2 on the Pt catalysts as opposed to the Pd and Rh catalysts, which saw a decrease in the methane conversion.