Precious metal catalysts are noble metals widely used in the chemical industry owing to their ability to speed up the chemical process. Gold, palladium, platinum, rhodium, and silver are some of the examples of precious metals. They possess an incompletely filled d-orbital to lend electrons or withdraw electrons from the reagent, depending on the nature of the reaction. precious metal catalysts for wide range of applications, such as pharmaceuticals, agrochemicals, petrochemicals, chemicals, environment and material sciences.