Which of these is a shape selective catalyst?

Options

A. ZSM-5
B. ZUV-2
C. PSP-3
D. YOI-3

Answer

To determine which of the given options is a shape-selective catalyst, we need to understand the concept of shape-selective catalysis.

### Step-by-Step Solution:

1. **Define Shape-Selective Catalysts**:
- Shape-selective catalysts are catalysts that facilitate reactions based on the size and shape of the reactant and product molecules. This means that the catalyst has a specific pore structure that allows only certain molecules to enter and react, while excluding others.

2. **Identify the Options**:
- The options given are:
1. ZSM-5
2. ZUV2
3. PSP3
4. YOI3

3. **Analyze Each Option**:
- **ZSM-5**: This is a type of zeolite, which is known for its shape-selective catalytic properties. It has a specific pore structure that allows it to selectively catalyze reactions involving certain sizes of molecules, such as converting alcohols into gasoline.
- **ZUV2**: There is limited information available about this catalyst, and it is not widely recognized as a shape-selective catalyst.
- **PSP3**: Similar to ZUV2, there is not enough information to classify this as a shape-selective catalyst.
- **YOI3**: This catalyst is also not well-known in the context of shape-selectivity.

4. **Conclusion**:
- Based on the analysis, ZSM-5 is the only catalyst among the options that is recognized as a shape-selective catalyst. It is specifically used in reactions that require a certain molecular size to pass through its pores.

### Final Answer:
The shape-selective catalyst among the options provided is **ZSM-5** (Option 1).

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