Which is not correct for hetergeneous catalysis? 

Options

A. The catalyst decreases the energy of activation
B. The surface of catalyst plays an important role
C. The catalyst actually forms a compound with reactants
D. There is no change in the energy of activation

Answer

To determine which statement is not correct regarding heterogeneous catalysis, we need to analyze each option provided in the context of the characteristics of heterogeneous catalysis.

### Step-by-Step Solution:

1. **Understanding Heterogeneous Catalysis**:
- Heterogeneous catalysis occurs when the catalyst is in a different phase than the reactants. For example, a solid catalyst may facilitate a reaction between gaseous reactants.

2. **Analyzing Option A**:
- "The catalyst decreases the energy of activation."
- This statement is correct. One of the primary functions of a catalyst is to lower the activation energy of a reaction, thereby increasing the reaction rate.

3. **Analyzing Option B**:
- "The surface of the catalyst plays an important role."
- This statement is also correct. The surface area of the catalyst is crucial because the reaction occurs at the surface where the reactants interact with the catalyst.

4. **Analyzing Option C**:
- "The catalyst actually forms a compound with reactant."
- This statement can be misleading. While catalysts may form temporary intermediates with reactants, they do not permanently change into a compound. They are regenerated at the end of the reaction. However, this statement is often considered correct in the context of catalysis.

5. **Analyzing Option D**:
- "There is no change in the energy of activation."
- This statement is incorrect. A defining feature of catalysts, including heterogeneous catalysts, is that they lower the activation energy of a reaction.

### Conclusion:
The statement that is not correct for heterogeneous catalysis is **Option D: "There is no change in the energy of activation."**