A catalytic converter is an ingenious automobile part that controls gas emissions. Credit goes to its French inventor Eugene Houdry who introduced this device in 1950, though it was mass-manufactured in automobiles only by 1975.
It filters the hot gases produced by the engine before they are expelled into the atmosphere through the exhaust pipe. Cars mostly use unleaded gas nowadays since leaded gas contaminates and clogs the catalytic converter, impairing its proper functioning.
The catalytic converter is in the form of a cylinder that is attached below the car, usually under the passenger seat. It may look small and is often referred to by its nickname “cat-con”, but it is a very powerful and useful device. Here is how it works:
* The unit consists of a honeycomb-like network of many tiny ceramic cells coated with special compounds that can react with these hazardous gases within milliseconds at high temperatures.
* The large number of cells spreads the surface area so that more of the poisonous substances can be trapped in a short duration. These get deposited onto the ceramic cells while the resultant emission is relatively free of toxic waste.
* Carbon monoxide, hydrocarbons and nitrogen compounds are byproducts of incomplete fuel combustion in the engine, when molecules of hydrogen, carbon and nitrogen combine with oxygen and escape the burning process.
* These three gas groups have been recognized as toxic waste by the EPA (Environmental Protection Agency) since they affect human health and pollute the environment with smog and acid rain.
* Three-way catalytic converters use small traces of the precious metals to filter the three groups of hazardous gas. Palladium and Platinum catalyze the oxidation process and transform carbon monoxide into harmless carbon-dioxide and water vapor. Palladium and Rhodium act as reduction catalysts to break down the nitrogen compounds into nitrogen and oxygen.
For the catalytic converter to function properly, other factors such as temperature, air/fuel mixture and engine running should be ideal. The catalytic compounds in the converter are not sufficient to clean the gas emission in case of a lean air/fuel mixture. If the mixture is too rich, the converter unit will heat up and start melting; this molten bulk will block the exit of the exhaust gases.
Occasional inspection and cleaning of the catalytic converter is essential to remove any coolant deposits or burnt oil that leaked into this cleaning chamber. This will ensure high performance from the unit and keep the car running efficiently.