Which material is commonly used in the construction of three-way catalytic converters?

The most commonly used material in the construction of three-way catalytic converters is ceramic honeycomb. This material provides a high surface area for catalytic reactions while being lightweight and capable of withstanding high temperatures.

Ceramic honeycombs are designed to maximize the amount of exhaust gas contact with the catalyst materials that promote chemical reactions necessary for converting harmful emissions, such as carbon monoxide, hydrocarbons, and nitrogen oxides, into less harmful substances like carbon dioxide and nitrogen. The structure of the honeycomb allows for efficient flow of exhaust gases through the converter, enhancing the overall effectiveness of the emission control system.

In contrast, stainless steel is often used for the outer casing of the catalytic converter for durability and resistance to corrosion but is not the main component of the catalyst itself. Lead-based alloys and plastic composites are not suitable for high-temperature applications found in catalytic converters and do not provide the necessary catalytic properties required for effective emissions control. Therefore, ceramic honeycomb is the ideal choice in this context.