Sure, here’s the definition of catalyst:

Catalyst:

In chemistry and biochemistry, a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction. Catalysts are typically molecules that lower the activation energy required for a reaction to occur.

Mechanism:

• Catalysts bind to reactant molecules, forming an intermediate complex.
• The intermediate complex has a lower activation energy than the reactant molecules.
• The intermediate complex breaks down into products, releasing the catalyst.

Examples:

• Enzymes are catalysts in living organisms.
• Acids are catalysts in many industrial processes.
• Precious metals, such as gold and platinum, are catalysts in fuel cells.

Benefits:

• Catalysts increase the rate of reactions, making them occur faster.
• Catalysts reduce the activation energy required for a reaction to occur.
• Catalysts can be used to control the rate and direction of reactions.

Applications:

• Catalysts are used in a wide variety of industrial processes, including chemical synthesis, drug production, and pollution control.
• Catalysts are also used in a variety of biological processes, including metabolism and digestion.