CHEMISTRY COMMUNITY

What are differences between intermediates and catalysts?

A catalyst is consumed by a step but regenerated by a later step. An intermediate is created by a step but consumed by a later step.

Intermediate is created and then used up throughout the steps.
A catalyst is there when the reaction begins and is then recreated later on.

A catalyst doesn't get used up in a reaction, so even if it is used up in one of the steps, it'll be regenerated in another step. Intermediates are the products of one step that are then used as reactants in a following step.

A catalyst is used up in the beginning and then later recreated.
An intermediate is not there initially but is later formed as a product which cancels out with the next step.

Catalyst: There to begin with
Intermediate: Formed, not reactant/product

Intermediates exists to show the reaction mechanism and it cancels out if you combine the separate steps together. However, catalyst is consumed and will be regenerated in the next step, and it functions to lower the activation energy.

Catalysts appear as a reactant for the first step of the reaction mechanism, while intermediates are formed during the reaction. They are both left out of the overall equation of the reaction.

an intermediate is created and used up in a reaction while a catalyst is present in the beginning and the end of a reaction