CATALYST ARTICLE, METHOD FOR REDUCING ONE OR MORE CO, HC AND NOX LEVELS IN A EXHAUST GAS EMISSION FLOW, EXHAUST GAS TREATMENT SYSTEM AND METHOD FOR MANUFACTURING A CATALYST ARTICLE

摘要

The present invention relates to a three-way conversion catalyst (twc) composition and a catalyst article comprising such a catalyst composition suitable for at least partially conversion of gaseous hydrocarbons (hc), carbon monoxide (co ) and nitrogen oxides (nox). In general, the catalyst article includes a catalyst substrate having a plurality of channels adapted for gas flow, each channel having a wall surface and a catalytic coating on the surfaces or inside of the wall pores. the catalytic coating generally includes a first wash coating with a platinum group metal (pgm) component and a first refractory metal oxide support and a second wash coating having a plurality of palladium rhodium nanoparticles and a second refractory metal oxide support.