Three-Way Catalytic Converter is a unit mounted in the exhaust system of the engine that converts simultaneously three major contaminants carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) into harmless water (H2O), carbon dioxide (CO2) and nitrogen gas (N2). As an active pollution control technology, it is widely applied in the automotive industry.

The Operational Principle of Three-Way Catalytic Converter

When high temperature exhaust gas passes through the three-way catalytic converter unit, the wash-coat in catalytic converter enhances the catalytic activity of the three gases CO, HC and NOx and oxidation-reduction chemical reaction occurs, in which most of the CO is oxidized to be colorless nontoxic carbon dioxide under high temperature; HC compound is oxidized to be water (H2O) and carbon dioxide; NOx is reduced into nitrogen gas and oxygen gas. The exhaust becomes less harmful and environmental friendly.

Failure Model of Three-Way Catalytic Converter

1. Three-Way Catalytic Converter generally fails in mechanical damage, high temperature aging, lead poisoning, chemical masking, etc. among which, high temperature aging and lead poisoning result in fatal damage to catalyst. Whatever form of failure will finally reduce the catalytic reaction of device. As a result, the chemical reactions do not work, exhaust contaminant increases rapidly and the atmospheric environment is polluted. 2. The reason for overheating of Three-Way Catalytic Converter is caused by excessive heat from the exhaust gases. When the catalyst components including precious metals such as platinum, palladium and rhodium on substrate are at high temperature for over period of time, precious metals are sintered. The temperature usually exceeds 900°C.

How to Determine the Failure of Three-Way Catalytic Converter

You can stop by any emission test center near you to have an emission specialist to emission test your vehicle. If it meets the standard, your converter most likely works. Also, if a converter stops working, you will notice a nuisance smell from the exhaust.