Selective adsorption of CO on CuCl/Y adsorbent prepared using CuCl sub(2) as precursor: Equilibrium and thermodynamics

Zeolite Y supported CuCl (CuCl/Y) has been prepared with CuCl sub(2) as precursor by a monolayer dispersion method, followed by activation with CO. The samples are investigated for CO adsorption and characterized by inductively coupled plasma optical emission spectrometry, X-ray diffraction, N sub(2) adsorption/desorption and X-ray photoelectron spectroscopy. The characterization results reveal that CuCl sub(2) supported on zeolite Y can be completely reduced to CuCl after activation at 663 K in CO, and the monolayer dispersion capacity of CuCl on zeolite Y support is 5 mmol/g zeolite Y. The resulting adsorbent displays high CO adsorption capacity, high CO/N sub(2), CO/CH sub(4) and CO/CO sub(2) adsorption selectivities, and excellent reversibility and regenerability. The adsorption equilibrium isotherms of CO on the adsorbents at temperatures up to 333 K can be well fitted by both the Langmuir and Sips models, and the integral thermodynamic data of Gibbs' energy change ( Delta G), entropy change ( Delta S) and enthalpy change ( Delta H) are calculated from the fitted Langmuir adsorption equations. The negative Delta G and Delta H values indicate that the adsorption process of CO on CuCl/Y adsorbent is spontaneous and exothermic. The negative Delta S value indicates that the adsorbed CO molecules on the adsorbent are in an ordered arrangement.