The catalytic converters use following metal as a catalyst for reducing the emission of poisonous gases

Options

A. Aluminum
B. Lead
C. Platinum
D. Cast iron

Answer

To answer the question regarding which metal is used as a catalyst in catalytic converters for reducing the emission of poisonous gases, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Catalytic Converters**:
- Catalytic converters are devices used in automobiles to reduce harmful emissions from the exhaust gases. They facilitate chemical reactions that convert toxic gases into less harmful substances.

2. **Identifying the Metals Used**:
- The question provides a list of metals: aluminium, lead, platinum, and cast iron. We need to determine which of these metals are used as catalysts in catalytic converters.

3. **Eliminating Incorrect Options**:
- **Aluminium**: While it is a useful metal, it is not typically used as a catalyst in catalytic converters.
- **Lead**: This metal is actually harmful and can deactivate catalysts, so it is not used in catalytic converters.
- **Cast Iron**: This is primarily used for structural purposes and not as a catalyst in this context.

4. **Identifying the Correct Catalysts**:
- The metals that are commonly used as catalysts in catalytic converters are **platinum**, **palladium**, and **rhodium**. Among the options given, platinum is the only one listed that is known to be used as a catalyst.

5. **Conclusion**:
- Therefore, the correct answer to the question is **platinum**.

### Final Answer:
The metal used as a catalyst in catalytic converters for reducing the emission of poisonous gases is **platinum**.

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