The use of alumina carrier

① Load catalytically active components. Alumina with a small specific surface area (or a material with only a small number of coarse pores) is usually used to support catalyst active components with high specific activity. The use of this type of carrier can eliminate the diffusion effect in the pores and reduce deep oxidation side reactions in processes aimed at selective oxidation. For example, the silver catalyst used in the oxidation of ethylene to ethylene oxide uses α-alumina as a carrier. Alumina with a large specific surface area has a well-developed pore structure, which can highly disperse the loaded catalyst active components into particles, and prevent the active component particles from sintering and growing up during use with the help of the barrier function of the carrier. It is a widely used Alumina support used. For example, noble metals such as palladium, platinum, rhodium, etc. are dispersed on an alumina carrier to make a hydrogenation catalyst, which can improve the utilization rate of precious metals.
② The acidity of the alumina surface and the loaded active components constitute a dual-functional catalyst. For example, the platinum-alumina catalyst used in platinum reforming, in which alumina serves as both a carrier and one of the active components of the catalyst. In some cases, there is a strong interaction between the alumina support and highly dispersed metals (such as platinum), which can affect the catalytic properties of the metal.