A catalytic converter is the device on an exhaust system of a vehicle used to reduce the carbon emissions from the engine. It works by using a catalyst to produce a chemical reaction to convert poisonous and harmful gases such as carbon monoxide to the less harmful substance carbon dioxide. There are three types of catalytic converters; two-way, three-way, and three way + air, with each type using a slightly different method and chemistry to reduce the harmful emissions. Older models used a pelletised catalyst but most modern ones are now designed with free-flowing honeycomb ceramic catalyst, and it depends on vehicle size, age and weight which catalytic converter will be found.
Two-Way Converter
A two-way converter has two simultaneous functions, firstly to convert the carbon monoxide by oxidising it into carbon dioxide, while oxidising unburnt hydrocarbons (unburnt and partially burnt fuel) into carbon dioxide and water, which is known as a combustion reaction. The two-way converter is commonly found on diesel engines but cannot control nitrogen oxides, which makes way for the three-way converter:
Three-Way Converter
The three-way converter has three simultaneous functions; like the two-way it oxidises carbon monoxide into carbon dioxide and also oxidises unburnt hydrocarbons into carbon dioxide and water, but it also addresses the problem of nitrogen oxides, and reduces the nitrogen oxides to nitrogen and oxygen.
Three-Way + Air
The three-way + air converter performs the same functions as the three-way converter but has secondary air pumped into the middle of the converter between two separate catalyst coated ceramic substrates. The addition of air improves the oxidation capabilities of the converter.
Generally you can identify the most catalyst coating by finding those enzymes that contains the maximum number of substrate binding site. The higher the number of substrate biding site, the more is the catalyst coating in it.
Two-Way Converter
A two-way converter has two simultaneous functions, firstly to convert the carbon monoxide by oxidising it into carbon dioxide, while oxidising unburnt hydrocarbons (unburnt and partially burnt fuel) into carbon dioxide and water, which is known as a combustion reaction. The two-way converter is commonly found on diesel engines but cannot control nitrogen oxides, which makes way for the three-way converter:
Three-Way Converter
The three-way converter has three simultaneous functions; like the two-way it oxidises carbon monoxide into carbon dioxide and also oxidises unburnt hydrocarbons into carbon dioxide and water, but it also addresses the problem of nitrogen oxides, and reduces the nitrogen oxides to nitrogen and oxygen.
Three-Way + Air
The three-way + air converter performs the same functions as the three-way converter but has secondary air pumped into the middle of the converter between two separate catalyst coated ceramic substrates. The addition of air improves the oxidation capabilities of the converter.
Generally you can identify the most catalyst coating by finding those enzymes that contains the maximum number of substrate binding site. The higher the number of substrate biding site, the more is the catalyst coating in it.
