The pore size distribution of activated carbon refers to the proportion and distribution of pores of different sizes within the activated carbon. Based on their diameter, pores are usually classified into micropores (less than 2 nm), mesopores (2-50 nm) and macropores (greater than 50 nm).

• MicroporesThese pores provide a high specific surface area and are the main area where the activated carbon adsorbs small molecules (e.g. gases, heavy metal ions, etc.).
• MesoporesMesopores have good extensibility and are suitable for adsorption of larger molecules, such as certain organic solvents and gases.
• MacroporesThese pores are mainly used for the transport of substances and are not usually involved in direct adsorption, but help to improve the adsorption rate of the activated carbon.

The pore size distribution of activated carbon has a significant effect on its performance. Uniformity of pore size distribution and proper pore structure will significantly improve adsorption efficiency. 

Too many micropores can lead to poor adsorption of macromolecules by the activated carbon, while too many macropores can lead to low surface area and poor adsorption. The ideal pore size distribution should be tailored to the needs of different applications.

• Adsorption capacityThe pore size distribution directly affects the adsorption capacity. Micropores provide more adsorption surface area and are suitable for small molecules; mesopores improve the adsorption rate; and macropores accelerate the passage of fluids and improve the overall adsorption efficiency.
• Adsorption rateDifferent pore sizes have different adsorption rates. Micropores and mesopores are more suitable for adsorption of liquids and gases, while macropores increase the mass transfer rate.
• Selective adsorptionPore size distribution: The specific pore size distribution favors the selective adsorption of specific molecules or ions. Micropores are suitable for small molecules, while macropores are suitable for larger organic molecules or solvents.

Different types of pore size distribution are suitable for different applications:

• Water treatmentThe application of activated carbon in water treatment is mainly based on the adsorption of mesopores and micropores for the removal of contaminants such as organic matter and heavy metals. For the removal of smaller molecules, the higher the proportion of micropores, the more favorable.
• Air purificationActivated carbon for air purification requires good gas adsorption capacity, usually a combination of micropores and mesopores, to effectively remove harmful gases, odors and VOCs (volatile organic compounds).
• Metal recoveryIn metal recovery, activated carbon needs to have a large surface area and a suitable pore structure. Activated carbon with a high level of micropores and mesopores is usually selected for efficient adsorption of metal ions.

The pore size distribution of activated carbon is one of the key factors affecting its performance. By selecting activated carbon with proper pore size distribution, its adsorption effect can be optimized in different applications.

We offer a wide range of activated carbon products to meet the pore size distribution requirements of different fields and help customers solve various adsorption problems.