shape selective catalysis is a reaction catalysed by

Options

A. enzymes
B. ziegler - Natta Catalyst
C. zeolites
D. platinum

Answer

To solve the question "Shape selective catalysis is a reaction catalyzed by," we need to analyze the options provided: enzymes, Ziegler-Natta catalysts, zeolites, and platinum.

### Step-by-Step Solution:

1. **Understanding Shape Selective Catalysis**:
- Shape selective catalysis refers to a catalytic process where the catalyst's structure allows it to selectively catalyze reactions based on the size and shape of the reactant and product molecules. This means that only certain molecules can fit into the catalyst's active sites.

2. **Analyzing the Options**:
- **Enzymes**: While enzymes are biological catalysts that can show selectivity, they do not specifically exhibit shape selective catalysis in the same way as zeolites.
- **Ziegler-Natta Catalysts**: These are used in polymerization reactions but are not primarily known for shape selectivity.
- **Zeolites**: Zeolites have a unique honeycomb-like structure with pores of specific sizes. This structure allows them to selectively catalyze reactions based on the size and shape of the molecules involved. They are well-known for their shape selective catalytic properties.
- **Platinum**: Platinum is a metal catalyst that does not exhibit shape selectivity in the same manner as zeolites.

3. **Conclusion**:
- Based on the analysis, zeolites are the catalysts that exhibit shape selective catalysis due to their pore structure, which allows them to selectively catalyze reactions based on the size and shape of the reactants.

### Final Answer:
Shape selective catalysis is a reaction catalyzed by **zeolites**.

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