Catalytic ignition during methane oxidation on platinum: Experiments and modeling

Abstract

The ignition behaviour of methane-air mixtures on a platinum-foil catalyst was studied at atmospheric pressure over the entire range of fuel to air ratios. The measured surface ignition temperatures showed a continously decreasing trend with increasing fuel:air ratio up to very fuel rich mixtures, which could be reproduced using a very simple analytical model indicating strong site competition between methane and oxygen on the catalyst surface. In parallel, steady state experiments during methane oxidation in a Pt coated monolith were modeled with a detailed monolith reactor model, comprising heat-, mass- and impulse-balance and a detailed elementary step surface reaction mechanism. A close fit between experimental and modelling results was obtained. The two approaches were then combined by comparing the results of dynamic simulations of the ignition behaviour of the detailed monolith model with the experimental results on the Pt foil catalyst.