Application of Porous Phosphate Heterostructure Materials for Gas Separation (original) (raw)

In this study, the adsorbents Cu +-3SiPPH723 and Cu 2+-3SiPPH723 were prepared starting from a silica-expanded zirconium phosphate heterostructure, 3SiPPH(0.2), which was subjected to an ion exchange with Cu(I) and Cu(II). These materials were characterized using powder X-ray diffraction, X-ray photoelectron spectroscopy, ammonia thermally programmed desorption, hydrogen temperature-programmed reduction, and N 2 adsorption (77 K). The equilibria and kinetics of adsorption of pure propylene (C 3 H 6) and propane (C 3 H 8) were studied using a conventional glass high-vacuum volumetric device, equipped with grease-free valves, in the temperature range of 273-393 K. The starting material, 3SiPPH(0.2), presented a high acidity and irreversible chemisorption of the olefin, which increases with temperature. Unlike the support, the irreversible adsorption of the olefin on the Cu +-3SiPPH723 and Cu 2+-3SiPPH723 samples decreases with increasing temperature and disappears at 393 K, showing a very high selectivity toward propylene. The C 3 H 8 adsorption in all the samples was always reversible. On the basis of the results of this study, both Cu +-3SiPPH723 and Cu 2+-3SiPPH723 samples can be efficiently applied in the separation of a C 3 H 6 / C 3 H 8 mixture at 393 K. Cu +-3SiPPH723 would have the highest efficiency, because its capacity for C 3 H 6 adsorption was higher than that for the Cu 2+-3SiPPH723 sample.