The addition of a catalyst to the decomposition reaction of hydrogen peroxide significantly increases the reaction rate. A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It achieves this by providing an alternative reaction pathway with a lower activation energy, which allows more reactant molecules to have sufficient energy to undergo the reaction.In the case of hydrogen peroxide H2O2 decomposition, the reaction can be slow at room temperature without a catalyst. The reaction is as follows:2H2O2 2H2O + O2When a catalyst, such as manganese dioxide MnO2 , potassium iodide KI , or catalase an enzyme found in living organisms , is added to the reaction, the activation energy is lowered, and the reaction rate increases significantly. This results in a faster production of water H2O and oxygen gas O2 .The catalyst achieves this by forming intermediate species during the reaction, which quickly break down to form the products and regenerate the catalyst. In this way, the catalyst remains unchanged at the end of the reaction and can continue to catalyze further decomposition of hydrogen peroxide.