Heterogeneous catalysts are an important topic in inorganic and industrial chemistry, as they play a major role in increasing the rate of chemical reactions without being consumed during the reaction. In this type of catalysis, the catalyst exists in a different phase from the reactants. Usually, the catalyst is in the solid phase, while the reactants are in the gaseous or liquid phase. The reaction typically occurs on the surface of the catalyst, where the reacting molecules are first adsorbed onto the surface, then the chemical reaction takes place, and finally the products are released from the surface. The efficiency of a heterogeneous catalyst depends largely on its surface area and the activity of the active sites present on its surface. The larger the surface area of the catalyst, the greater the ability of reactant molecules to interact with it, which leads to an increase in the reaction rate. For this reason, materials with large surface areas such as metal oxides, activated carbon, and silica are often used as catalyst supports to enhance catalytic performance. Many transition metals are commonly used as heterogeneous catalysts due to their high ability to adsorb and activate molecules. Examples of such metals include platinum, nickel, palladium, and iron. These metals can weaken chemical bonds in reactant molecules, making it easier for new bonds to form and for reaction products to be generated. One of the most important industrial applications of heterogeneous catalysts is the production of ammonia through the Haber–Bosch process, where iron is used as a catalyst to accelerate the reaction between nitrogen and hydrogen to produce ammonia. Catalysts are also widely used in petroleum refining processes such as catalytic cracking, as well as in catalytic converters in automobiles to transform toxic gases into less harmful substances. Heterogeneous catalysts also play a significant role in modern environmental technologies, particularly in the removal of pollutants from air and water. For example, certain metal oxides can act as catalysts in advanced oxidation processes to break down toxic organic compounds into less harmful substances. The study of heterogeneous catalysis continues to be an important area in modern inorganic chemistry. Researchers are constantly working on developing new catalysts with higher efficiency and better stability. Special attention is also given to designing nanocatalysts with large surface areas and high catalytic activity, which can improve the efficiency of chemical processes while reducing energy consumption and raw material usage in chemical industries. Al-Mustaqbal University, the leading private university in Iraq