Catalysts Conceptually

[czhu22]

Can someone conceptually explain catalysts? I understand they decrease activation energy, but how? If they aren't acting in the reaction.

[Damin Rawlins 3B]

Catalysts are substances that increase the rate of a chemical reaction by lowering its activation energy, the minimum amount of energy required for the reaction to occur. Although they are not consumed or changed during the reaction, they interact with the reactants to form a transient intermediate state with lower activation energy than the uncatalyzed reaction. The mechanism by which catalysts lower the activation energy depends on the specific catalyst and reaction, but generally involves three steps. First, the reactants adsorb onto the surface of the catalyst, forming weak bonds with it. This interaction can help break some of the bonds within the reactant molecules, making them more reactive and thus lowering the activation energy required for the reaction to occur. Second, the reactants undergo chemical transformations while they are adsorbed onto the surface of the catalyst, leading to the formation of an intermediate state that has a lower activation energy than the uncatalyzed reaction. Finally, the products of the reaction desorb from the surface of the catalyst, leaving it unchanged and available to catalyze further reactions.

[Ryan Sebti 3I]

Catalysts lower activation energy for a reaction in multiple ways, two of which are:
orienting the reacting particles to make successful collisions more likely, or
reacting with the reactants to form an intermediate that requires a lower energy to form the product.

Both of these methodologies are ways a catalyst actually speeds up a reaction, by lowering the activation energy.
Hopefully this helps understanding catalysts more conceptually!