Catalysis is a process that speeds up chemical reactions without being consumed in the reaction itself. Catalysts, the substances that facilitate this process, lower the activation energy required for a reaction to occur. This means that reactions can happen more quickly and efficiently, which is essential in various industrial applications, such as the production of ammonia or petrochemicals. There are two main types of catalysis: homogeneous and heterogeneous. In homogeneous catalysis, the catalyst is in the same phase as the reactants, often in a solution. In heterogeneous catalysis, the catalyst is in a different phase, typically solid, while the reactants are in a gas or liquid phase. Both types play crucial roles in chemical manufacturing and environmental processes.