Hydrocarbon processing devices and systems are constructed to modify the combustion characteristics of hydrocarbon fuels and emissions for the purpose of emissions reduction and to increase the overall performance characteristics of the engine. According to one exemplary embodiment, a catalytic device for processing a fluid containing hydrocarbons includes a reactive body formed of a plurality of metallic materials arranged in a layered structure. The plurality of metallic materials is formed of at least two different materials. The body has an inner core member having a first density and another region, that is formed along a longitudinal length of the rolled layered structure, has a second density which is less than the first density.