A catalyst always increases the rate of a reaction. This is the defining characteristic of a catalyst.

Here's why:

* Lowering Activation Energy: Catalysts work by providing an alternative reaction pathway with a lower activation energy. This means that more molecules have enough energy to overcome the energy barrier and react, leading to a faster reaction rate.

* Not Consumed: Catalysts are not consumed in the reaction. They participate in the reaction mechanism but emerge unchanged at the end, ready to catalyze more reactions.

Important Note: While a catalyst always increases the rate of a reaction, it does not change the equilibrium position of the reaction. It simply helps the reaction reach equilibrium faster.

Let me know if you'd like more details on how catalysts work!