Adsorption of benzene on a range of activated Y zeolites

The adsorption of benzene on calcined LiY, NaY, KY, RbNaY, CsNaY, CeKY, HY and on a range of calcined and reduced nickel-exchanged Y zeolites has been investigated by infrared and chromatographic techniques. The nature of the alkali-metal cation is shown to influence strongly the extent of the zeolite–benzene interaction; the strength of benzene adsorption increases in the order: CsNaY < RbNaY < KY < NaY < LiY. Benzene interacted weakly with the CeKY and HY samples. Reduction of the nickel-exchanged Y zeolites lowered the overall strength of benzene adsorption. The strongly adsorbed aromatic phase (on LiY, NaY or the Ni2+-exchanged forms) closely resembles crystalline benzene. Benzene desorption from the zeolite surface as a function of temperature is also considered.