Thermodynamics of hydrogen adsorption on the zeolite Ca-Y

摘要

Variable-temperature infrared spectroscopy was used for a thermodynamic study on hydrogen adsorption on the zeolite Ca-Y. Adsorption renders the H-H stretching mode infrared active, at 4078 cm~(-1); and simultaneous measurement of IR absorbance and hydrogen equilibrium pressure, over a range of temperature, allowed standard adsorption enthalpy and entropy to be determined. They resulted to be ΔH°= -15.0(±1.0) kJ mol~(-1) and ΔS° = -127(±10)J mol~(-1) K~(-1), respectively. These relatively high values of adsorption enthalpy and entropy are discussed in the broader context of corresponding data for other hydrogen adsorbents.