The performances of NaY-SiO2, Pt/NaY-SiO2, and V2O5/NaY-SiO2 in removing ethanol from water containing air stream were investigated using a fixed-bed adsorber. The adsorption capacity of Pt/NaY-5iO(2) is much greater than those of NaY-SiO2 and V2O5/NaY-SiO2, even though the adsorption rate was lower. To elucidate the causes of difference in the performance, the surface species on the adsorbents were characterized by using XAS and FT-lit The results indicate that active Pt clusters on NaY not only adsorb ethanol but also catalytically convert the adsorbed ethanol to ethoxides and aldehyde. Those Pt adsorbed species could spillover to displace sodium and acid site bound water, leaving the Pt clusters for further adsorption, and thus increase ethanol adsorption capacity. However, the adsorption process involves slow diffusion of the surface species from Pt clusters to NaY-SiO2, resulting in lower overall adsorption rate. In contrast, the VO4 species formed on NaY-SiO2 just covers up the adsorption sites without adsorption capability, leading to decrease in adsorption capacity.