A catalytic converter is one of the most critical parts of your vehicle’s exhaust system. Typically, they are located close to your engine, and their job is to break down the vehicle’s pollution before it is expelled out the tailpipe. The catalytic converter uses catalysts, which are chemicals that speed up a reaction, to convert the gases expelled from the motor into less harmful compounds. There are three main compounds which a cat converter converts and they are:
- Carbon monoxide
- Nitrogen oxides
The simplest way to imagine a catalytic converter is to think of a metal box that is pumped full of the hot exhaust fumes from the running engine, which converts the chemical-filled air, with cleaner air; which is then forced out the back end of your vehicle. It works like any other filter, like for water or air.
The catalyst in the converter comes in the form of palladium or platinum and is glazed onto a ceramic honeycomb or onto ceramic beads confined in a container similar to a muffler, which is then attached to the exhaust pipe.
How Does It Work?
A catalytic converter contains chemicals which speed up the process of chemical reactions but without changing themselves during the process. The catalysts break down dangerous exhaust gases that are emitted from the engine by separating the atoms. There are two main types of catalysts inside the converter. One of these catalysts removes the oxygen from nitrogen through a reduction process. The other catalyst turns carbon monoxide into carbon dioxide by adding the oxygen which is removed from the nitrogen. This process is called oxidization.
A secondary oxidation reaction that turns unburned hydrocarbons into carbon dioxide and water also occur in the catalytic converter.
What does this all mean? When these processes take place, the vehicle creates less smoke and fewer odors out of the exhaust. Cars without catalytic converters don’t have these catalyst processes turning harmful gases into the cleaner air and are less environmentally friendly.
Catalytic converters are also a reason we use unleaded fuel in cars, as the lead in fuels used in older vehicles prevents the catalysts from breaking down the pollution in the exhaust gases.
What was the reason for catalytic converters?
If you are old enough to remember the 70’s and 80’s you will remember how smog-filled skies covered cities and put holes in the ozone layer. Since unleaded fuels became a global standard, pollution levels have dropped by huge numbers. Since 1990, with the introduction of unleaded petrol, the quantity of airborne lead has diminished so much, that environmental agencies stopped monitoring for the pollutant over ten years ago.
Do They Work?
Without catalytic converters, our cities would have a whole lot more smog than they currently do, and the pollution would be far more harmful to people and especially the environment.
As catalytic converters play a crucial role in reducing air pollution, they are undoubtedly beneficial. However, some environmental bodies, claim that they are doing more harm to the environment than good because of the quantity of nitrous oxide they produce.
However, with more advanced technology, new catalytic converters yield far less nitrous oxide and the effect they have on reducing the dangerous emissions is noticeable.