How do catalysts form temporary intermediate compounds with reactants?

Catalysts accelerate chemical reactions by entering into temporary chemical combinations with reactants to form intermediates, which then react more readily to produce the final products and regenerate the catalyst. Because the catalyst is not consumed, a single molecule can facilitate the transformation of many reactant molecules.12

The formation of these intermediates occurs through various mechanisms depending on the system:

• General Chemical Catalysis: A catalyst ($C$) reacts with a reactant ($A$) to form an intermediate ($Z$). This intermediate then decomposes to yield the final product ($B$) while releasing the original catalyst ($C$) to repeat the cycle.3
• Enzymatic Catalysis: Enzymes often attract substrates to an active site to form an enzyme-substrate complex. In some cases, this involves the formation of a covalent intermediate, where a chemical bond forms between a specific group on the enzyme surface and a part of the substrate (such as an acyl-serine bond in acetylcholinesterase). Other enzymes may catalyze reactions without forming covalent bonds, instead using physical attractions like electrostatic or hydrophobic forces.4

These processes effectively lower the activation energy required for the reaction to proceed.1