Engineers have attempted to reduce undesirable emissions from internal combustion engines by using apparatuses, such as catalytic reformers that include pre-combustion catalysts. An apparatus of the present invention includes an apparatus housing that defines at least a first flow inlet and includes an upstream support and a downstream support. The upstream support defines a plurality of second flow inlets, and the downstream support defines a first portion and a second portion of a plurality of outlets. A plurality of second flow paths are defined by a plurality of tubes extending between the plurality of second flow inlets and the second portion of the plurality of outlets. At least one first flow path is defined by a plurality of surfaces and fluidly connects the first flow inlet with the first portion of the plurality of outlets. At least one surface of the plurality of surfaces is coated with a pre-combustion catalyst. The downstream support preferably includes a plate with a predetermined porosity.