What Are Catalytic Converters? A Detailed Overview On Catalytic Converters

What Exactly is a Catalytic Converter?

A catalytic converter is an exhaust emission control device present in a car to convert toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. 

Catalytic converters are usually used with the internal combustion engines in the car that are fueled by gasoline or diesel, including lean-burn engines, and sometimes on kerosene heaters and stoves. There are two types of reactions that take place in catalytic converters and they are: oxidation and reduction reactions.

Types of Catalytic Converters

The following are types of catalytic converters:

Oxidation catalyst converter 

Dual bed catalyst converter 

Three-way catalyst converter 

Oxidation Catalyst Converter 

The oxidation catalyst is a type of catalytic converter that helps in lowering engine emissions through chemical reactions that convert carbon monoxide, hydrocarbons and aldehydes into carbon dioxide and water.

Dual bed Catalyst Converter 

A dual-bed catalyst is a type of catalytic converter that enables high conversion of syngas to gasoline-range liquid hydrocarbons.

Three-way Catalyst Converter 

The three-way catalysts were developed to perform multiple oxidation reactions and reduction reactions. A three-way catalyst oxidizes exhaust gas pollutants including hydrocarbons (HC) and carbon monoxide (CO) and it also reduces nitrogen oxides (NOx) into harmless components such as, water (H2O), nitrogen (N2), and carbon dioxide (CO2).

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Types of Materials Used In Making Catalytic Converters 

Catalytic converters are made from metals, ceramics and even irons: 

  1. Metallic Catalytic Converters
  2. Ceramic Catalytic Converters
  3. Foil Catalytic Converters 

Metallic Catalytic Converters 

What exactly is a metallic catalytic converter?

Metallic catalytic converters are catalytic converters made using corrugated [FeCrAl] foils which are rolled into a spiraling cylinder shape then put in a furnace to form an alumina (Al2O3) layer.

Usually metallic catalytic converters are used for two & three wheelers. 

Ceramic Catalytic Converters

What exactly is a ceramic catalytic converter?

A ceramic catalytic converter is a type of catalytic converter that is made by covering the honeycomb-like, porous ceramic monolith with oxide washcoat, which acts as support for the precious metal particles. 

Ceramic catalytic converters are used for four wheelers or larger vehicles.

Foil Catalytic Converters

What exactly is a foil catalytic converter?

A foil converter is a type of catalytic converter that is usually made from aluminum. It is used to make laminates that are formed by layering aluminum foil with other materials such as paper and polymers.

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Note: Precious metals are used in different fractions in all catalytic converters.

Uses of Catalytic Converters

1.Catalytic converters are used in cleaning the exhaust. Considering how fuel contains carbon and hydrogen, and how it reacts with air, which contains oxygen, there would be emissions of CO2 and H2O (water vapor), but a car’s engine will also produce numerous other substances that might be avoided. Catalytic converters are used in the conversion of exhaust emissions gotten from vehicles into environment friendly gases. Some of the gases that are converted include NOx (N2O & NO2), CO (Carbon monoxide), HC (hydrocarbons) and Soot. These gases are converted to Nitrogen (N2), Carbon Dioxide (CO2) , Water Vapor (H2O) by the catalytic converters.

2.Larger engines require larger catalytic converters which are needed in tackling large flow exhaust emissions.

3.Catalytic converters are used in stationary engines like generators etc. and also used in chimneys that give out large amounts of gases to the environment.

Disadvantages of Using Catalytic Converters

However, one of the disadvantages of catalytic converters is that they are very expensive to obtain/replace. Furthermore, because carbon dioxide is a byproduct of the reaction that occurs inside catalytic converters, widespread use of catalytic converters has contributed to increased carbon dioxide levels in the atmosphere.

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FAQ’S

What are catalytic converters used for?

A catalytic converter is a device that is installed in the front part of a vehicle’s exhaust system, near the engine, to reduce the emission of gaseous pollutants such as carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HCs).

How does a catalytic converter work?

A catalytic converter employs a catalyst chamber to convert harmful compounds from engine emissions into safe gases such as steam. It works by breaking up the dangerous molecules in the gases produced by a car before they are released into the atmosphere.

Do catalytic converters actually work?

Catalytic converters use chemical reactions to convert harmful substances in a car’s exhaust gasses, such as carbon monoxide, nitric oxide, nitrogen dioxide, and hydrocarbons, into less harmful substances such as carbon dioxide and water vapour.

Where is the catalytic converter on a car and what does it look like?

The catalytic converter is typically located on the underside of a vehicle as part of the exhaust system, between the engine and the muffler. It appears to be another muffler.