Vehicular pollution control-removal of carbon monoxide through catalytic converters

In an attempt to find a substitute to noble-metal based catalysts in the ca talytic converters for the removal of CO from automotive exhaust, non-noble metal based catalysts of perovskite based oxides were tested. Perovskites of the structure ABO(3): where A cation had La, Ba or Ca and B cation had C o or Fe were used for the reaction. Substituted perovskite of the form A(1- x)A ' xBO3, where A ' was Ce metal, was also used. The perovskite catalyst were tested in unsupported as well as supported forms. The supports used we re zirconia, ceria or a mixture of the two in different proportions. The re sults indicate that among the unsupported catalysts, LaCoO3 is the best. Am ong the substituted catalysts, La0.3Ce0.7CoO3 gave the best performance sho wing 100% CO conversion at 200 degreesC. The support, zirconia (20%) and ce ria (80%) mixture was found to be the best combination. The durability runs up to 6 h show the activity pattern in the order : La0.3Ce0.7CoO3> La0.6Ce 0.4CoO3> LaCoO3.