Differential heats, isotherm and entropies of n-pentane adsorption on LiZSM-5 and CsZSM-5 zeolites

Abstract

Artificially synthesised zeolites are widely used in water purification devices as adsorbents, ion exchangers, molecular sieves; they are used as electron donors and acceptors. Also, zeolites are currently the most important catalysts for the processing of various hydrocarbon raw materials. Synthetic zeolites ZSM-5 are highly efficient catalysts of these processes. For o characterisation of zeolite channels and estimation of sorption volume npentane are the most suitable. n-Pentane fills all sorption space and adsorbed with higher energy. This paper presents the results of the basic thermodynamic characteristics and isotherms of n-pentane adsorption in Cs3,17ZSM- 5 and Li3,37ZSM-5 zeolites at 303 K. A system consisting of a universal high-vacuum adsorption unit and a Tian-Calvet type differential modified microcalorimeter, DAC-1-1A, coupled to it was used to measure isotherms and differential heats of adsorption. The correlation between adsorption-energy characteristics was found and the molecular mechanism of n-pentane adsorption in CsZSM-5 and LiZSM-5 zeolites in the whole filling region was revealed.