Heterogeneous catalysis and homogeneous catalysis are two distinct types of catalysis that differ in terms of reactant adsorption and activation energy barriers.1. Reactant Adsorption:Heterogeneous Catalysis: In heterogeneous catalysis, the catalyst is in a different phase usually solid than the reactants usually gas or liquid . The reaction occurs at the interface between the catalyst and the reactants. The reactants are adsorbed onto the surface of the catalyst, where they form bonds with the catalyst's active sites. This adsorption process is crucial for the reaction to occur, as it brings the reactants closer together and facilitates the breaking and forming of bonds.Homogeneous Catalysis: In homogeneous catalysis, the catalyst and the reactants are in the same phase usually liquid . The catalyst is typically a soluble molecule that interacts with the reactants in the solution. There is no adsorption process involved in homogeneous catalysis, as the reactants and catalyst are already in close proximity and can readily interact with each other.2. Activation Energy Barriers:Heterogeneous Catalysis: The activation energy barrier is the minimum energy required for a reaction to occur. In heterogeneous catalysis, the adsorption of reactants onto the catalyst surface lowers the activation energy barrier. The catalyst provides an alternative reaction pathway with a lower activation energy, allowing the reaction to proceed more quickly. The catalyst also helps to stabilize the transition state, further reducing the activation energy barrier.Homogeneous Catalysis: In homogeneous catalysis, the catalyst interacts with the reactants in the solution, forming intermediate species or complexes. These intermediates have lower activation energy barriers than the uncatalyzed reaction, allowing the reaction to proceed more quickly. The catalyst also stabilizes the transition state, further reducing the activation energy barrier.In summary, the main differences between heterogeneous and homogeneous catalysis in terms of reactant adsorption and activation energy barriers are the adsorption process and the way the catalyst interacts with the reactants. Heterogeneous catalysis involves adsorption of reactants onto a solid catalyst surface, while homogeneous catalysis involves direct interaction between the catalyst and reactants in the same phase. Both types of catalysis lower the activation energy barrier, allowing reactions to proceed more quickly.