REMOVAL OF AUTOMOTIVE POLLUTANTS USING NEW METAL-SUPPORTED METAL CATALYST

A NEW TECHNIQUE IS PROPOSED FOR THE PREPARATION OF METAL-SUPPORTED METAL (MSM) CATALYSTS. THE KEY FEATURE OF THIS TECHNIQUE INVOLVES THE PREPARATION OF A THIN LAYER OF POROUS METAL ON TOP OF A METAL SUBSTRATE SUCH THAT THE POROUS METAL SURFACE IS AN INTEGRAL PART OF THE METAL SUPPORT. SUBSEQUENT INTEGRATION OF PT AND RH ON THE POROUS METAL SURFACE WILL PRODUCE THE MSM CATALYST. THIS CATALYST IS USED AS A THREE-WAY CATALYST IN CATALYTIC CONVERTERS FOR THE REMOVAL OF NOX, HYDROCARBONS AND CO FROM AUTOMOBILE EXHAUST GAS. THE MSM CATALYST HAS A MUCH BETTER THERMAL CONDUCTIVITY THAN THE STATE-OF-THE-ART THREE-WAY CATALYST USING CERAMIC SUPPORTS. THE IMPROVEMENT IN HEAT TRANSFER WILL RESULT IN A MORE THERMALLY STABLE CATALYST, WHICH WILL EXTEND THE LIFE OF THE CATALYTIC CONVERTER. THE IMPROVEMENT IN HEAT TRANSFER WILL ALSO GIVE MORE EFFICIENT USE OF THE PRECIOUS METAL COMPONENTS OF THE CATALYST BECAUSE OF MORE HOMOGENEOUS HEAT DISTRIBUTION. BETTER UTILIZATION OF THE PRECIOUS METALS WOULD RESULT IN LOWER COSTS OF THE CATALYST CONVERTER UNIT. THE PROPOSED MSM CATALYST WILL BE MORE DURABLE AND MORE COST EFFECTIVE THAN THE STATE-OF-THE-ART THREE-WAY CATALYST PRESENTLY USED.