To make it a little clearer how an automotive catalytic converter works, let’s take a look at what its main elements are. Without going into detail, let’s list only the main elements on which it is built.
Table of Contents
Substrate
The substrate is the internal structure of the catalyst, on which the catalyst coating and precious metals are deposited. There are several types of substrates. Their main difference is the material used to make them. Most often, it is an inert substance that stabilizes the active particles on its surface.
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The active material of a catalyst usually consists of aluminum dioxide and compounds such as cerium, zirconium, nickel, barium, lanthanum, and others. The purpose of the coating is to expand the physical surface of the substrate and to serve as a base on which precious metals are deposited.
How does an automotive catalytic converter work
Precious metals
As JunkCarsUs notes, the precious metals present in a catalytic converter serve to perform an extremely important catalytic reaction. Commonly used precious metals are platinum, palladium, and rhodium, but in recent years numerous manufacturers have begun to use gold.
The casing
The casing is the outer shell of the device and contains the substrate and other elements of the catalyst. The material that the casing is typically made of is stainless steel.
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Tubes
Tubes connect the car’s catalytic converter to the car’s exhaust system and engine. They are made of stainless steel.
How does a car catalytic converter work
- JunkCarsUs emphasizes that it is important for an internal combustion engine to have a stable combustion process of the air-fuel mixture in its cylinders. During this process, harmful gases such as carbon monoxide, nitrogen oxides, hydrocarbons, and others are produced.
- If your car does not have a catalytic converter, all of these extremely harmful gases, once released into the exhaust manifold from the engine, will pass through the exhaust system and will go directly into the air that we breathe.
- If the vehicle has a catalytic converter, the exhaust gases will pass from the engine to the muffler through the honeycomb substrate and react with the precious metals. As a result of the chemical reaction, harmful substances are neutralized, and only harmless exhaust, consisting mostly of carbon dioxide, is released into the environment from the exhaust system.
- We know from our chemistry classes that a catalyst is a substance that causes or accelerates a chemical reaction without affecting it. Catalysts are involved in reactions, but they are neither reactants nor products of a catalytic reaction.
- When the working temperature of the catalyst reaches 500 to 1,200 degrees Fahrenheit (ca. 649 °C) or 250 to 300 degrees Celsius, two things happen reduction, and immediately after that an oxidation reaction. This sounds a little complicated, but what it really means is that the molecules of the substance lose and gain electrons at the same time, causing their structure to change.
- The reduction (absorption of oxygen), which takes place in the catalyst, aims to turn nitrogen oxide into an environmentally friendly gas.
