Khelifa Amine, Benchehida Leila, Derriche Zoubir
Laboratoire de Structure, Elaboration et Applications des Matériaux Moléculaires (S.E.A.2M.), Département de Chimie, Université de Mostaganem, B.P. 981, R.P., Mostaganem 27000, Algeria.
J Colloid Interface Sci. 2004 Oct 1;278(1):9-17. doi: 10.1016/j.jcis.2004.05.033.
The adsorption of CO2, at intervals of 30 K from 303 K was carried out on M(n+)X zeolites (M(n+)=Ni2+ or Cr3+) exchanged at different degrees. The structural regularity of the zeolite lattice of NaX and the existence of well-defined cavities within which the adsorbate molecules are lodged suggest that it should be possible to use various isotherm equations. Several models were thus used to describe the experimental isotherms. The best fit of adsorption isotherm data is obtained with the Sips model. The Volmer model also describes satisfactorily the isotherms of CO2 adsorption by NaX, Ni(x)X, and Cr(x)X. Analysis of the isosteric heat reveals a character energetically heterogeneous for NaX and Ni(x)X samples exchanged at a higher degree of Ni2+ exchange and at low coverage. Specific interaction is also obtained between the adsorbate molecules and Cr(x)X exchanged at a lower degree. From these considerations, hypotheses will be advanced to describe the behavior of the adsorbed phase within zeolitic cavities.
在不同交换度的M(n+)X沸石（M(n+)=Ni2+或Cr3+）上，于303 K至30 K每隔30 K温度下进行了CO2吸附实验。NaX沸石晶格的结构规整性以及存在明确的孔洞（吸附质分子可驻留在其中）表明，有可能使用各种等温线方程。因此，使用了几种模型来描述实验等温线。吸附等温线数据与Sips模型拟合最佳。Volmer模型也能令人满意地描述NaX、Ni(x)X和Cr(x)X对CO2的吸附等温线。等量吸附热分析表明，对于高度Ni2+交换且低覆盖度的NaX和Ni(x)X样品，其吸附具有能量不均匀的特性。在较低交换度的Cr(x)X上，吸附质分子之间也存在特定相互作用。基于这些考虑，将提出假设来描述沸石孔洞内吸附相的行为。
