Catalysis is the process of modifying a chemical reaction with the use of a catalyst. This process only works with chemicals that have an existing reaction, and it is used to accelerate the reaction for commercial purposes. Catalysis occurs faster than a standard chemical reaction because catalysts require less activation energy, which is the minimum level of energy necessary to initiate a chemical reaction. When a chemical is placed with a compatible catalyst, there is a reduction in the free energy required for the chemical to reach the transition state for that particular reaction. Catalysts can influence the reaction environment, depending on the specific reaction requirements. There are two main types of catalysts used for catalysis; heterogeneous or homogeneous. A heterogeneous catalyst has molecules that are not in the same phase as the reactants, whereas a homogeneous catalyst’s molecules are in the same phase as the reactants. Typically, a heterogeneous catalyst is solid, whereas the reactants are gaseous or liquid. The reactants are adsorbed on active sites on the surface of a heterogeneous catalyst, and an interaction occurs. This interaction causes the molecules to become more reactive. An electrocatalyst is a heterogeneous catalyst that is employed specifically in fuel cell engineering to improve the properties and working of the fuel cell.