The activity of many catalysts is pH-sensitive. For instance, enzymes, which are biological catalysts, typically have an optimal pH range in which they achieve maximum catalytic activity. Deviation from this optimal pH can result in decreased activity due to [denaturation]() or changes in the ionization state of active sites. In heterogeneous catalysis, the surface properties of solid catalysts can also change with pH, affecting the adsorption and desorption of reactants and products.
