Johnson Matthey Public Limited Company

Johnson Matthey & Co., Limited

Alan F Diwell

Guy Richard Chandler

Raj Rao Rajaram

Brian Harrison

William David Evans

Gary James Acres

John W Hayes

Barry John Cooper

Graham P Ansell

Christopher Hallett

Andrew Salathiel

In the control of pollutants such as NOin the exhaust gases from internal combustion engines, ozone is reacted with NO to form NO, which is then reduced catalytically to N.

Combatting air pollution

In the control of pollutants such as NO in the exhaust gases from internal combustion engines, ozone is reacted with NO to form NO , which is then reduced catalytically to N , by reacting NO with ammonia. The NO produced can react with the particulates of Diesel engine to exhaust gas to regenerate a particulate filter.

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.

Catalyst of copper oxide and ceria

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.

Process for making a lead-tolerant catalyst system for purifying exhaust

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.

Exhaust gas purification

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.

Catalyst for the purification of an exhaust gas

This invention relates to catalyst for use in the control of atmospheric pollution and, in particular to the purification of exhaust gases from internal combustion engines. Specific catalysts of the present invention comprise:

Catalyst

This invention relates to catalyst for use in the control of atmospheric pollution and, in particular, to the purification of exhaust gases from internal combustion engines. Specific catalysts of the present invention comprise: A. ruthenium or an alloy thereof and a metal oxide capable of forming a stable mixed oxide (or 'ruthenite') with ruthenium dioxide; B. a compound formed by ruthenium dioxide and a metal oxide capable of forming a stable mixed oxide (or ruthenite) with ruthenium dioxide; and C. a mixed oxide containing ruthenium, the oxide being selected from the group consisting of oxides of the pyrochlore type A.sub.2 B.sub.2 O.sub.7, the perovskite type ABO.sub.3, the ilmenite type B.sub.2 O.sub.3 and the spinel type AB.sub.2 O.sub.4. Particularly good results have been obtained where the platinum/ruthenium ratio is within the range 25- 95 wt.% platinum and 5 - 75 wt.% ruthenium.

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Reading, United Kingdom

Alan F Diwell