Energies, Vol. 11, Pages 1575: Catalytic Oxidation of Synthesis Gas on Platinum at Low Temperatures for Power Generation Applications (Energies)

This paper addresses the issues related to the low-temperature catalytic oxidation of synthesis gas at high pressures under lean-burn conditions. The purpose of this study is to explore the mechanism responsible for the interplay between carbon monoxide and hydrogen during their combined oxidation process. Particular attention is given to the temperature range from 500 to 770 K, which is relevant to the catalyst inlet temperature encountered in catalytic combustion gas turbine systems. Computational fluid dynamics simulations were performed by using a numerical model with detailed chemistry and transport. Reaction path analysis was conducted, and the rate-determining step in the reaction mechanism was finally identified. It was shown that there is a strong interplay between carbon monoxide and hydrogen during the combined oxidation process. The addition of hydrogen causes a great change in the adsorbed species on the surface of the catalyst. At temperatures as low as 600 K, the presence of hydrogen makes the active surface sites more available for adsorption, thus promoting the catalytic oxidation of carbon monoxide. The coupling steps between the two components make a small contribution to the promoting effect. At temperatures below 520 K, the presence of hydrogen inhibits the catalytic oxidation of carbon monoxide due to the competitive effect of hydrogen on oxygen adsorption.