Why is Coconut Activated Carbon preferred for Air & Odour purification?

Activation is a process in which carbon is made porous to the extent that 75% of its volume is filled with empty space. The density of carbon thus gets reduced to 500 kg/m3 from 2.15 kg/m3, this is achieved by administering steam to red hot charcoal. Other similar molecules can also be used for this process. Activation is done with chemicals also, but the extent of porosity generated by steam is much more compared to chemical activation. This is the reason why activated carbon is used as an adsorbent; no other material can develop so much empty space by such a simple process.