Why can activated carbon absorb poison gas but not oxygen?

1、Generally speaking, there are two kinds of adsorption: one is physical adsorption, which is through the van der Waals force between molecules, which is the unbalanced electron cloud in the outer layer of the molecule, which causes the molecule to be adsorbed with polarity; the other is chemical adsorption. , which is the chemical reaction between the adsorbed substance and the adsorbed substance to generate other products.

2、Physical adsorption can generally be desorbed (reduced) by simple heating or other treatments, and chemical adsorption is more complicated due to the formation of bonds with each other.

3、 Most of activated carbon adsorption belongs to physical adsorption. Countless pores similar to molecular sieves are formed inside the activated carbon. Because the inside of the pores is a place where the static electrode is unbalanced, the surface effect of the activated carbon causes the static electricity to be unbalanced, so it has a strong adsorption force. It can be seen that the dust adhesion on the wall and the corner of the home is similar. The corner is a place where static electricity is unbalanced, and it is easy to absorb dust). Even for macromolecules such as chlorine Cl2 (here, macromolecules refer to large electron cloud radius), the outer electron cloud can be distorted, resulting in electrostatic imbalance and adsorption.

4、Most of the toxic gases are compounds (except chlorine), and their static electricity is not balanced, so they are easily adsorbed by activated carbon. Gases such as oxygen and nitrogen are statically balanced, and the molecules are not large (the nucleus is wrapped in its own electron cloud. ”, so the adsorption is difficult.