This invention relates to power sources which may be used underwater and to such sources in which catalytic combustion of the fuel takes place. The power source according to the invention includes two or more catalytic combustors each comprising a fuel injector, a supported catalyst having a ceramic or metallic support, a high surface area refractory metal oxide coating on the support and a catalytic layer on the coating the catalytic layer comprising a platinum group metal selected from the group consisting of Ru, Rh, Pd, Ir, Pt alloys of the said metals with each other and alloys of one or more of the said metals with one or more base metals such that at least 10% by weight of the said catalyst is a platinum group metal each combustor having a separate fuel supply and a separate heat exchange unit which form part of the same boiler.
A catalytic combustor for a combustion turbine that employs a protective nickel aluminide diffusion barrier on its inside and outside surfaces with a porous alumina, zirconia, titania, and/or ceria, and bond phase coating on the outside surface in which a catalyst is contained.
