Microcatalytic Combustion of H2 on Pt/Al2O3-Coated Nickel Foam

Abstract

A new catalyst support, nickel foam, was suggested for use in a microcatalytic combustor. Al2O3 was coated on nickel foam to increase the surface area using a coating slurry prepared by a modified sol-gel process. Rough surface was observed in the SEM examination of Al2O3-coated nickel foam. H2 catalytic combustion was carried out using Pt/Al2O3-coated nickel foam to confirm the reactivity as a catalyst for combustion with different flow rates and equivalence ratios. The height of combustion chamber was 1mm. Combustion was successful, and conversion rates were over 99%. When the equivalence ratio was 0.1, even though the H2 concentration was the lower flammability limit of the homogeneous gas phase combustion of H2 and air mixture, the conversion rates was more than 92%. Temperature and conversion rates increased more rapidly at the beginning of reaction, when equivalence ratio was low for fixed H2 flow rates. These were explained by the influence of water condensed in the combustor at low temperature.