Carbon materials have become a hot research topic at home and abroad due to their excellent functions and common structure.
granular activated carbon (gac) They are often used as catalysts and catalyst carriers in the application of catalytic carrier activated carbon, which effectively improves the power of precious metals. At the same time, the drum of new carbon materials Qi also continues to attract people's attention.
Because the catalytic carrier activated carbon has a large specific surface area, it can be used as a catalyst carrier to provide a load and reaction center. Defects in crystallization produce active centers, and the existence of active centers is the primary condition for catalysts to have catalytic activity. The existence of unsaturated bonds in activated carbon can be regarded as crystal defects in a sense. Therefore, activated carbon can be used as a catalyst.
The support of the catalyst is to adsorb the catalyst on the surface of the catalyst carrier. The catalytic carrier activated carbon carrier is mainly used to support the catalyst so that the catalyst has specific physical properties, and the carrier itself generally does not have catalytic activity. The catalyst loading often has the following effects:
1. Disperse the catalyst on the surface of the carrier to obtain a higher specific surface area and improve the catalytic efficiency of the catalyst per unit mass.
For example, if platinum is loaded on activated carbon, if a molecular sieve is used as a carrier, platinum can achieve a degree of dispersion close to the atomic level.
2. The catalyst carrier can prevent the active components from sintering during use and improve the heat resistance of the catalyst.
www.coalactivatedcarbon.com 3. For some strong exothermic reactions, the carrier dilutes the active components in the catalyst to meet the thermal balance requirements.
4. Carriers with good thermal conductivity, such as metals, silicon carbide, etc., help to remove the heat of reaction and avoid local overheating of the catalyst surface.
5. The carrier can also load some catalysts originally used in homogeneous reactions on a solid carrier to make a solid catalyst, such as [solid acid catalyst] made by adsorbing phosphoric acid in diatomaceous earth, and enzymes are loaded on the carrier. Into the immobilized enzyme.
