What is a catalyst? How does it affect the reaction rate?

Catalysts include substances that accelerate reactions, and are not included in the compounds of this reaction. At the end of the reaction, no change in the amount of catalyst is noted, which cannot be said about other reagents.

The reaction proceeds faster due to the catalysts. At the same time, they react with the compounds of this reaction, but at the end they are split into a product and a catalyst. Then the catalyst reacts with the substance again, the process can be repeated many times.