Three Way Catalyst（TWC） Tri-PGM CNG Catalyst Low PGM loading Three Way Catalyst GPF Locomotives and Industrial Catalysts Methanol-to-Hydrogen Reformer Diesel Oxidation Catalyst Diesel Particulate Filter Selective Catalytic Reduction Ammonia Slip Catalyst Industrial Catalyst Diesel Particulate Filter Diesel Particulate Filter Double descending SCR exhaust aftertreatment system