Combined modification of zeolite NaY by phenyl trimethyl ammonium bromide and potassium for ethylene gas adsorption

Zeolite NaY was co-modified with 0.5 mM phenyl trimethyl ammonium bromide (PTAB) and 5.0 mM KNO3. Three types of modification were employed and there were two successively modifications (K+/PTAB-zeolite NaY and PTAB/K+-zeolite NaY) and a simultaneous modification (PTAB + K+/zeolite NaY). The modified zeolites were characterized by surface area and pore size analysis, X-ray diffraction, and atomic emission spectroscopy. The XRD studies indicated that the modification did not lead to structural destruction. The surface area analysis indicated 10% of external surface area and 90% of internal surface area. The adsorptions of ethylene gas over these modified zeolites NaY were investigated. All of the three differently modified zeolites showed better ethylene adsorptivity after modification. The zeolite that displayed the best ethylene adsorptivity was the zeolite that was modified by the simultaneous modification method. The ethylene adsorption was raised from 82.5 cm3 g−1 for the unmodified to 116.6 cm3 g−1 for the simultaneously modified zeolite.

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► Zeolite NaY was co-modified with K+ ions and PTAB.
► K+ ions modified internal pores whereas PTAB modified the external areas.
► Co-modified zeolite NaY adsorbed ethylene better than the singly modified ones.
► Simultaneously modified method is more effective than the successive modifications.