* Platinum (Pt): The most commonly used catalyst. It's effective at oxidizing carbon monoxide (CO) to carbon dioxide (CO2) and oxidizing hydrocarbons (HC) to carbon dioxide and water (H2O).
* Palladium (Pd): Similar to platinum, palladium is also highly effective at oxidizing CO and HC. It's often used in combination with platinum to reduce costs.
* Rhodium (Rh): Rhodium is primarily used to reduce nitrogen oxides (NOx) to nitrogen (N2) and oxygen (O2).
These metals are often used in varying ratios depending on the type of engine and desired emissions reduction.
Additionally, cerium oxide (CeO2) is also a key component of the catalytic converter. It acts as an oxygen storage and release agent, helping to maintain optimal oxygen levels for the catalytic reactions.
The specific combination and proportions of these elements can vary depending on the manufacturer and the type of catalytic converter.
