US Patent 9597663 Exhaust cleaning catalyst

An exhaust cleaning catalyst, with which precious metal sintering is inhibited and which has greater exhaust cleaning abilities, has a substrate and a catalyst coating layer provided on the substrate. The catalyst coating layer has a precious metal that serves as an oxidation and/or reduction catalyst. The precious metal has Rh-containing metal particles in which rhodium (Rh) coexists with a base metal selected among platinum group elements excluding rhodium. The Rh-containing metal particles have an average rhodium content of 0.1% to 5% by mole with the total amount of the base metal and rhodium being 100% by mole.