Catalytic reactions are chemical reactions that are modified or accelerated by the presence of a catalyst. A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. Catalytic reactions are used in various industries, including petrochemicals, pharmaceuticals, and environmental remediation, to improve efficiency, selectivity, and yield of desired products. Catalysis can occur through various mechanisms, such as homogenous catalysis (where the catalyst is in the same phase as the reactants) or heterogeneous catalysis (where the catalyst is in a different phase). Overall, catalytic reactions play a crucial role in increasing the sustainability and efficiency of chemical processes.