To know what the heck a catalytic converter IS, we must first explore what the heck a catalytic converter IS NOT. A catalytic converter is not:
So…what the heck is it, then?
A catalytic converter takes all the harmful pollution your vehicle creates, and makes it not-as-harmful before it is expelled out of the exhaust system.
I’m glad you asked. Chemistry is how it works. Your engine creates nitrogen, carbon dioxide, and water vapor as it uses fuel. It also creates some sneakier, more harmful emissions like carbon monoxide, nitrogen oxides, and hydrocarbons. A catalytic converter consists of 2 catalysts: a reduction catalyst and an oxidation catalyst. A 3-way catalytic converter also has a control system.
Let’s hop on the Catalytic Converter train…
The reduction catalyst typically uses platinum and rhodium to help reduce the nitrogen oxide emissions. When an those nitrogen oxide molecules contact the catalyst, it removes the nitrogen atom from the molecule and holds on to it. That releases the oxygen from the molecules. The nitrogen atoms just bond with other nitrogen atoms that are also stuck to the catalyst.
The oxidation catalyst typically uses platinum and palladium to reduce the unburned hydrocarbons and carbon monoxide by oxidizing (burning) them. This catalyst aids the reaction of the carbon monoxide and hydrocarbons with the remaining oxygen in the exhaust gas.
The control system monitors the exhaust stream, and uses this information to control the fuel injection system. An oxygen sensor tells the engine computer how much oxygen is in the exhaust. The engine computer can then adjust the air-to-fuel ratio, which measures the amount of oxygen in the exhaust gas. There has to be enough oxygen in the exhaust gas for the oxidization catalyst to burn the unburned hydrocarbons and carbon monoxide.
Catalytic converters usually last about 10 years or so, but there are some issues that can shorten that lifespan:
So, there you have it. Now you know what the heck a catalytic converter is NOT, what the heck it IS, and how the heck it works. Mother Earth loves catalytic converters. So should you!
Tell me what other automotive parts baffle you. I’ll tell you what the heck they are!