Hydrogen assisted catalytic combustion of methane on platinum

The objective of this paper is to study hydrogen assisted catalytic combust ion of methane on platinum experimentally and numerically. In the experimen t, we measure the exit temperatures of methane/hydrogen/air mixtures flowin g at atmospheric pressure through platinum coated honeycomb channels. A sin gle channel of this monolith is investigated numerically by a two-dimension al Navier-Stokes simulation including an elementary-step surface reaction m echanism. Furthermore, a one-dimensional time-dependent simulation of a sta gnation flow configuration is performed to elucidate the elementary process es occurring during catalytic ignition in the mixtures studied. The depende nce of the hydrogen assisted light-off of methane on hydrogen and on methan e concentrations is discussed. The light-off is primarily determined by the catalyst temperature that is a result of the heat release due to catalytic hydrogen oxidation. Increasing hydrogen addition ensures light-off, decrea sing hydrogen addition requires an increasing methane feed for light-off. ( C) 2000 Elsevier Science B.V. All rights reserved.