Precious metals, also known as noble metals, are metals which are inactive toward chemical reaction and are chemically highly stable. Gold, palladium, platinum, rhodium, and silver are some of the examples of precious metals. Precious metal catalysts are those which consist of highly dispersed nano-scale precious metal particles supported on a high surface area such as carbon, silica, and alumina. These catalysts have several applications in a variety of industries such as refinery, petrochemicals, polymer, chemicals, pharmaceuticals, automotive, and environmental. Each precious metal catalyst has unique characteristics. These catalysts are primarily used for organic synthesis reactions.
The precious metal catalysts offer a wide variety of advantages. They are highly stable and do not easily form oxides by oxidation. They also do not readily dissolve in acid or alkaline solution. The melting point of precious metals is higher than that of base metals. The selection of precious metals is a crucial factor that needs to be considered while deciding on their application. For example, palladium or carbon can be used for hydrogenation of maleic acid in water, which is in acidic condition. However, nickel catalyst cannot be used for the same reaction, since nickel undergoes leaching. Precious metal catalysts have high thermal stability, as a result of which they find numerous applications in the automotive field.
The nano-scale metal particles present in the precious metal catalysts easily absorb hydrogen and oxygen in the atmosphere. The absorbed hydrogen and oxygen readily react with many substitutes under mild conditions. Thus, if mild reaction conditions are maintained, relatively high product yield can be achieved by reducing the formation of by-products. With advancements in the field of nano-technology, progress is underway regarding the preparation technology of precious metal catalysts in the recent years. This has ensued in saving of energy, high productivity, and reduction in the cost of production. These advantages of the precious metal catalysts are expected to drive the market during the forecast period.
Precious metal catalysts are, however, expensive and undergo high price volatility. Also, the usage of platinum metal as a fuel cell catalyst faces a major drawback, that is, of high residue of carbon monoxide being formed, that hinders the process of hydrogen electro oxidation. Lack of proper precaution, such as maintenance of appropriate reaction conditions, may lead to the precious metals turning toxic during their use in reactions. Research is underway in order to replace precious metals with their substitutes for use in organic synthesis reactions, as the reserves of precious metals such as gold, platinum, silver, palladium, rhodium, etc. are limited in the earth’s crust. These drawbacks of the precious metal catalysts are anticipated to hamper the growth of the market during the forecast period.
Some of the major key players in the precious metal catalysts market are: BASF, Evonik Industries AG, Johnson Matthey Plc., Heraeus Group, Clariant International Ltd., Umicore, and Alfa Aesar.