Abstract

On the basis of granular synthetic zeolites NaY, HY, and ZSM-5, adsorbents containing nanoparticles of silver, cobalt, molybdenum, and tungsten were obtained. The samples have a lower surface polarity in comparison with the initial zeolites, which is reflected in the selectivity of a number of samples with respect to argon. This is due to the fact that the argon molecule interacts with zeolites only through nonspecific forces. Modification was performed by interacting with reverse-micellar solutions of nanoparticles. The actual sizes of metal particles and their distribution over the surface of the modified samples of zeolites have been determined by the method of transmission electron microscopy. The samples’ equilibrium adsorption capacities for oxygen and argon (25°С and atmospheric pressure) and the separation coefficient of the argon–oxygen mixture as the ratio of Henry’s coefficients have been determined. It has been demonstrated that samples of the NaY zeolite modified with silver nanoparticles have the separation coefficient value of the argon–oxygen gas mixture equal to 1.6.

Highlights

  • Introduction separation by thePSA method [1,2,3,4,5]

  • Nanocomposites based on γ-Al2O3 with Au or Ru NPs adsorbed on the surface [6] have high catalytic activity in the reaction of hydrogen isotope exchange

  • The change in the concentration of transition metals in solutions during adsorption and washing with solvents were controlled by the intensity of optical absorption spectra

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Summary

Introduction

Introduction separation by thePSA method [1,2,3,4,5]. Modifying the surface of high-silicon zeolites of Y and ZSM types by introducing metal nanoparticles (NPs) is one of the promising directions for creating nanocomposite materials with specified properties for gas purification and separation due to the unique properties of NPs.The presence of transition metals on the surface of materials changes their adsorption and catalytic properties. Nanocomposites based on γ-Al2O3 with Au or Ru NPs adsorbed on the surface [6] have high catalytic activity in the reaction of hydrogen isotope exchange. Modification of the silica surface by metal nanoparticles reduces the polarity of these adsorbents. As shown in [8,9], the contributions of specific interactions of polar compounds on silicas containing NPs metals are less than on the initial one. The authors explain this fact by shielding the active centers of the silica gel surface with metal nanoparticles

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