Abstract: Catalysts, particularly for combating air pollution from the exhaust gases of internal combustion engines, consist essentially of an intimate mixture of copper oxide and ceria, the weight of the copper oxide being less than the weight of the ceria.

Abstract: A process for improving the lead tolerance of a motor vehicle exhaust purification catalyst system of the type comprising a platinum group metal catalyst carried on alumina. The improvement derives from impregnating the alumina with barium moiety and firing at at least 400.degree. C. before subsequent impregnation with the metal catalyst moiety.

Abstract: An oxidation catalyst for use in a catalytic exhaust gas purification unit comprises a substrate on which a refractory metal oxide is coated, a base metal component and one or more metals from the Platinum Group. The catalyst is highly effective when a metallic substrate is employed and the loading of the refractory metal oxide coating is relatively high. The base metal is useful for catalysts having a ceramic substrate and a relatively low coating loading.

Abstract: This invention relates to catalysts suitable for the purification of exhaust gases. In particular a catalyst according to the invention comprises a compound selected from the group represented by the general formula A.sub.x M.sub.y O.sub.z in which A is one or more metals selected from the group consisting of Li, Na, K, Mg, Ca, Sr, Ba, Al, Sc, Y, the lanthanides, Ti, Zr, V, Cr, Mn, Fe, Co, Ni, Cu, Zn; M is a metal selected from the group consisting of Ir, Rh, Pt, Pd, and Ru; y has an integral or fractional value within the range from 0.1 to 3.0, z is an integer with a value from 2 to 7 and x has a value such that the compound is electrically neutral.