Here's a breakdown:

* Benzene is a cyclic aromatic hydrocarbon with the formula C₆H₆.

* Hydrogenation is the process of adding hydrogen (H₂) to a molecule.

* Catalyst: A catalyst is a substance that speeds up a chemical reaction without being consumed in the process. In this case, a metal catalyst like nickel, platinum, or palladium is used.

The reaction can be represented as:

C₆H₆ + 3H₂ → C₆H₁₂

Important note: The reaction requires high pressure and temperature.