Discipline: Mechanical Engineering
The performance of ceria-alumina as an oxidation catalyst for exhaust treatment of an experimental car in actual running condition was verified in Metro Manila. It was compared to the "Johnson Matthey Automotive Catalyst", a standard oxidation catalyst of monolithic structure. The carbon monoxide and hydrocarbon levels of the exhaust gases were measured using non-dispersive infra-red analyzer in the idling condition following standard procedures. Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analyses were both performed to check the elements deposited on the catalysts, as well as the compounds formed on the surface. The results showed that in leaded gasoline, ceria-alumina performed better than the standard oxidation catalyst, while in the unleaded fuel, the reverse was true. Elemental analysis showed that lead and sulfur were present on the surface. Cerium sulfate was also detected which confirmed that deactivation by sulfur was reversible. The ceria-alumina catalyst was demonstrated to be a practical catalyst to use for old cars without engine modification, although a secondary air source should be provided.