Heats of Adsorption and Adsorption Heterogeneity for Methane,Ethane,and Carbon Dioxide in MCM-41

摘要

We report the adsorption isotherms and the isosteric heats of adsorption of pure methane,ethane,and CO_2 and a mixture of methane and CO_2 in the periodic mesoporous silica MCM-41 using a multicomponent adsorption calorimeter of the Tian-Calvet type,looking in particular at the degree of heterogeneity in the adsorption of these species.The adsorption of methane and ethane in MCM-41 was found to be essentially homogeneous,while the adsorption of pure CO_2 and of CO_2 from a CO_2/methane mixture was found to be significantly heterogeneous,reflecting the electrostatic interactions between CO_2 and the adsorbent.