Question

Why heterogeneous compounds are adsorbed greater than homogeneous compounds?

Answer 1

Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent.
In order to give the explanation for the above statement let us assume the adsorption of two substances over the same adsorbent. One is a homogeneous substance for example hydrogen gas and lets say other is the heterogeneous substance say HCl gas. 
The homogeneous compounds at maximum will have just the vanderwaal forces of attraction operating between them, where as the heterogeneous substances will have other kind of attractions for example, the dipole dipole interactions or Hydrogen bonding etc. 
Now whenever we talk about adsorption, our main is to bring all the molecules of the adsorbate close to each other on the surface of adsorbent. If the forces of attraction holding different molecules is high, then the tendency of the molecules to come close to each other is also high and thus more will be the adsorption. .
hence adsorbtion is more in heterogeneous compounds