Stabilizers are functionally the opposite of catalysts — while catalysts and enzymes work to increase the rate of a chemical reaction, stabilizers work to hinder these reactions. Stabilizers work at a molecular and chemical level, preventing or altering reactions like corrosion, oxidation, or separation. For many of these stabilizers, their activity focuses on inhibiting the function of a catalyst or enzyme.
Stabilizers that act on catalytic reactions work by either preventing the formation of the catalyst-substrate complex or by modifying the catalyst's active site. Stabilizers can also do both simultaneously. Regardless of how it works, stabilizers degrade the effectiveness of the catalyst, preventing the enzyme from facilitating reactions.
Stabilizers can be grouped into one of two categories — irreversible agents and reversible agents. Irreversible agents act by catalyst poisoning, where a catalyst's activity is permanently destroyed or altered, preventing the reaction from ever occurring in that catalyst. Reversible agents, however, work by forming a non-permanent complex with the catalyst that prevents the reaction from occurring. When removed, reversible agents allow the catalyst to return to its original functionality.
Reversible agents are further split into two types, described below: