Catalyst support is a special part of solid catalyst. It is the dispersant, binder and support of the active components of the catalyst, and sometimes plays the role of Co catalyst or cocatalyst. Catalyst support, also known as support, is one of the components of supported catalyst. It is generally a porous material with a certain specific surface area. The active components of the catalyst are often attached to it. The carrier is mainly used to support the active components and make the catalyst have specific physical properties. However, the carrier itself generally does not have catalytic activity.
Requirements for catalyst support
1. It can dilute the density of active components, especially precious metals
2. And can be prepared into a certain shape
3. Sintering between the active components can be prevented to a certain extent
4. Can resist poison
5. It can interact with the active components and work together with the main catalyst.
Effect of catalyst support
1. Reduce catalyst cost
2. Improve the mechanical strength of catalyst
3. Improving the thermal stability of catalysts
4. Activity and selectivity of added catalyst
5. Extend catalyst life
Introduction to several primary carriers
1. Activated alumina: the most widely used carrier for industrial catalysts. It is cheap, has high heat resistance, and has good affinity for active components.
2. Silica gel: the chemical composition is SiO2. It is generally prepared by acidifying water glass (Na2SiO3). Silicate is formed after the sodium silicate reacts with acid; Silicic acid polymerizes and condenses to form polymers with uncertain structure.
SiO2 is a widely used carrier, but its industrial application is less than that of Al2O3, which is due to such defects as difficult preparation, weak affinity with active components, and easy sintering under the coexistence of water vapor.
3. Molecular sieve: it is a crystalline silicate or aluminosilicate, which is a pore and cavity system composed of silicon oxygen tetrahedron or aluminum oxygen tetrahedron connected by oxygen bridge bond. It has high thermal stability, hydrothermal stability and acid and alkali resistance
Post time: Jun-01-2022
