NOVEL CONCEPT PROTOTYPE OF LOW-POWER-CONSUMPTION ELECTRICALLY HEATABLE CATALYST

Electrically heated catalyst devices (EHCs) are important for treating exhaust gases in the 20 to 120 s warmup period after a cold start whe n about 70% of the total hydrocarbon (HC) and carbon monoxide (GO) Emi ssions from a modern gasoline powered vehicle are released. Although k nown for several years, EHCs have not been deployed because these devi ces are cost- and energy-intensive. An alternate EHC prototype propose d here is based on our reasoning that only the platinum group metals a nd the molecules undergoing oxidation need to be at light-off temperat ures and it is not necessary to waste energy to heat the whole catalys t. The concept prototype, fabricated on a glass coupon, resistively he ats the fluorine doped tin oxide film beneath the washcoat to bring a palladium-titania washcoat to the CO and HC light-off temperatures. Th e electrically powered concept prototype showed light-off temperatures of 250 degrees C and 260 degrees C for CO and HC, respectively, in la boratory tests with simulated exhaust gases at 25 degrees C. A device based on this concept is estimated to attain the 1-kW target power con sumption required for the deployment of the EHC.