Characterization of microporous solids by immersion calorimetry

This paper reviews the fundamentals and main applications of immersion calorimetry in the study of microporous adsorbents such as activated carbons, including carbon molecular sieves, and microporous zeolites. In the former case, it will be shown that immersion calorimetry into liquids of different molecular sizes easily allows for the assessment of the micropore size distribution. Furthermore, the use of liquids with different polarity permits the study of the evolution of the surface chemistry of these materials after different treatments. On the other hand, the study of zeolites with this technique is not as straightforward as in the case of carbonaceous materials, given the higher complexity of these systems. It will be shown that this technique can be used to analyze the evolution of the surface properties of zeolites A and X after thermal treatments at different temperatures and after ion-exchange. (C) 2001 Elsevier Science B.V. All rights reserved.