A combustion catalyst coating (36) applied to the surface of a ceramic
thermal barrier coating (34) which is supported by a metal substrate
(32). The microstructure of the thermal barrier coating surface provides
the necessary turbulent flow and surface area for interaction of the
catalyst and a fuel-air mixture in a catalytic combustor of a gas turbine
engine. The temperature gradient developed across the thermal barrier
coating protects the underlying metal substrate from a high temperature
combustion process occurring at the catalyst surface. The thermal barrier
coating deposition process may be controlled to form a microstructure
having at least one feature suitable to interdict a flow of fuel-air
mixture and cause the flow to become more turbulent than if such feature
did not exist.