The effect of metal ions in MNaY-zeolites for the adsorptive removal of tetrahydrothiophene

Abstract

The adsorptive removal of tetrahydrothiophene (THT) was carried out over transition metal ion-exchanged Na-Y zeolites. CuNa-Y,
CoNa-Y, NiNa-Y and FeNa-Y were prepared by a conventional ion exchange method from Na-Y using the nitrate solutions of corresponding
metals. N2 physisorption, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and X-ray diffraction were conducted to
characterize adsorbents. The temperature programmed desorption (TPD) of THT was also perfomed to probe the interaction between
the adsorbent and the THT. The crystal structure of Y-zeolite was completely destroyed in FeNa-Y, which resulted in a insignificant
amount of adsorbed THT. The breakthrough capacity, which is defined as the amount of sulfur adsorbed on the adsorbent before
detecting sulfur species by PFPD, decreased in the following order CuNa-Y>CoNa-Y>NiNa-Y>>FeNa-Y. For interaction between THT
and adsorbent, a TPD peak appeared over CoNa-Y at the highest temperature, which implies that the strongest interaction can
be made between THT and Co2+ in CoNa-Y.

Key wordsAdsorption-Tetrahydrothiophene-Zeolite-Ion-exchange-Fuel Cell