Noble Metal Catalysts on Metallic Substrates

The use of platinum group metal catalysts supported on ceramic monoliths for control of gaseous emissions from automobiles and chemical plant is now well established. Research in the Johnson Matthey Laboratories and at AERE Harwell, aimed at meeting the demand for more effective catalysts, has resulted in a new generation of platinum catalysts in which the ceramic substrate is replaced by a metal monolith. These metal substrate platinum catalysts are found to be more compact and more efficient than conventional ceramic structures. At the same time they overcome the structural limitations of ceramics with greater resistance to thermal shock and mechanical failure. The development of the metal substrate catalyst, and its use in hostile high temperature environments such as automobile emission control and catalytic combustion is described.