Synthesis of Ag/SBA-15 as adsorbent for propane/propylene separation

Mesoporous silica SBA-15 was used as support for the synthesis of pi-complexation adsorbents. Samples of mesoporous silica containing variable quantities of AgNO3 were prepared in order to study changes in the Ag+ dispersion produced by different thermal treatments. The samples were activated by heating at different temperatures in air. The solids were characterized by XRD, nitrogen adsorption, EDX, SEM, TEM, FT-IR, TPR and the corresponding propylene equilibrium adsorption curves were obtained. It was found that thermal treatment conducted at about 100 degrees C in air produces high salt dispersion and prevents the transformation in Ag2O or Ag degrees. Activated samples having intermediate values of Ag concentration showed the highest propylene adsorption capacity.