What is shape `-` selective catalysis ?

Explanation

### Step-by-Step Solution

1. **Definition of Catalysis**:
- Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst. Catalysts work by providing an alternative pathway for the reaction with a lower activation energy.

2. **Understanding Shape-Selective Catalysis**:
- Shape-selective catalysis is a type of catalysis where the catalyst's structure allows it to preferentially facilitate reactions involving specific reactants based on their shape and size. This selectivity is crucial for ensuring that only certain reactions occur, leading to desired products.

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