Catalytic converter transforms waste gases from the engines of many cars into carbon dioxide, nitrogen and water. The catalyst is made of

A catalytic converter is an exhaust emission control device used to reduce the toxicity of emissions from an internal combustion engine. It facilitates chemical reactions that convert harmful pollutants into less harmful substances. The device primarily utilizes precious metals from the platinum group as catalysts:

• Platinum (Pt) and Palladium (Pd): These serve as oxidation catalysts. They convert Carbon Monoxide (CO) and unburnt Hydrocarbons (HC) into Carbon Dioxide (CO₂) and Water (H₂O).
• Rhodium (Rh): This serves as a reduction catalyst. It converts Nitrogen Oxides (NO_x), which contribute to acid rain and smog, into harmless Nitrogen (N₂) and Oxygen (O₂).

While some modern research explores alternative materials, the standard combination used in automotive industry for decades involves platinum and rhodium. Copper and molybdenum are not the primary catalytic agents in these systems.