The adsorption energy affects the reaction kinetics and the stability of intermediates on the catalyst surface. Optimal adsorption energy ensures that reactants adhere to the catalyst surface just long enough to undergo necessary reactions. If the adsorption energy is too high, the reactants might adhere too strongly, making it difficult for products to desorb. Conversely, if the adsorption energy is too low, the reactants might not stay on the catalyst surface long enough to react.