Johnson Matthey Public Limited Company

David Scott Lafyatis

Todd Howard Ballinger

Raj Rao Rajaram

Paul Joseph Andersen

Andrew Peter Walker

Christopher John Bennett

Barry John Cooper

A catalyst system includes a three-way catalyst (TWC) mounted underfloor and an engine management system programmed to initiate an enrichment of the exhaust gases exiting the engine with at least one of CO and hydrocarbons and to add secondary air to the exhaust gases in the exhaust passage upstream of the TWC. This periodic enrichment and addition of secondary air causes catalytic oxidation of the at least one of CO and hydrocarbons over the TWC thereby raising the underfloor TWC temperature to at least 550&deg; C., preferably higher, in order to reduce sulphur poisoning of the catalyst and maintain the desired catalytic activity.

Method and system for maintaining efficiency of a three-way catalyst

Engine exhaust gas emissions are cleaned up using apparatus comprising an electrical heater, a first catalyst for oxidizing CO and H , and a hydrocarbon oxidation catalyst (which may be the same as the first catalyst). Engine management initiates electrical heating upon start-up of the engine, and ensures that there is sufficient CO and H and sufficient additional air supplied to the exhaust system, to provide chemical energy in the form of exotherm, whereby the hydrocarbon oxidation catalyst is speeded in reaching light-off temperature.

Combatting air pollution

Growing community of inventors

Frazer, PA, United States of America

David Scott Lafyatis