Every vehicle with an internal combustion engine pollutes the air, and it doesn’t even matter how old it is. Some cars, especially diesel ones, produce more gasses than others. So that’s the problem, which requires a solution. That’s why every single one of them has a catalytic converter. There are wide varieties of them, but some are made of different materials than others.
In every diesel or petrol-powered car, a catalytic converter is installed right after the engine and into the exhaust system. It is made from metal or ceramic and shaped like a cylinder, with small holes for airflow. Without it, all the gasses that engines produce would reach our atmosphere. Some of them are hazardous to the environment and our health. Most used ceramic converters are made of cordierite formed into a honeycomb shape and have square or triangular passageways. It is coated with aluminum oxide or even more expensive ones (palladium, rhodium, or platinum).
Ceramic and metallic converters
The difference between them is their price, difficulty in production, and efficiency. Most catalytic converters were made of ceramics. Still, nowadays, metallic ones are used more commonly. Mainly because they can offer a slightly smaller airflow resistance and start doing their job in lower temperatures. The gasses must reach a certain heat point for the catalytic converter to begin the cleaning process. Since the more minor airflow resistance is achieved with metal roll, it can provide way more surface for gasses to clean, compared to ceramic one.
One significant advantage of metallic ones is more significant thermal conductivity. By that, we mean it is easier for this catalytic converter to heat up. And it can be placed closer to the car engine, where gasses are way hotter, and it can do its job in higher temperatures. When you think of other ones, the ceramic substance is very vulnerable to heat and might crack easily. Another metallic substance advantage is that it is easier to produce in different shapes. Hence, there is a possibility of flowing gas turbulence increasing. That means exhaust will use more catalyst area and convert even more emissions.
Many may think a metallic catalytic converter is a cheaper option, but that is not entirely true. First of all, the catalyst is made of a precious metal. Platinum itself is the best for converting processes and is used commonly. It is unsuitable in many ways, primarily because of unwanted chemical reactions and high costs. But it can do both rhodium and palladium functions (reduction and oxidation catalyst). Of course, nickel can do this process, but it is not legal in the European Union. And there is copper, which is illegal in North America. So, there is no way to make one catalytic converter that could be used worldwide.
If there is a need to make one metallic converter, it’s ok, but if we need a batch of them, then ceramic is the way to go. Mainly because it is easier and cheaper to make it in large quantities.