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 1 mm. 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.

Keywords:

• Al₂O₃ sol-gel
• Microcatalytic combustor
• Metal support
• Nickel foam
• Pt/Al₂O₃

This research was financially supported by a grant to MEMS Research Center for National Defense funded by Defense Acquisition Program Administration.