Abstract: Pollutants in air or other fluids are converted to harmless compounds by positioning a catalyst coated reticulated foam in the path of the fluid flow. The reticulated foam is a three dimensional latticework of interconnected ligaments forming a porous, open-celled structure with a large internal surface area. Internal surfaces of the reticulated foam are coated with the catalyst. Catalytic conversion efficiency is maintained by fluid heat, an internal heating source, or external sources, such as combustion processes and radiation illumination.