Research output: Contribution to journal › Article › peer-review
Adsorption of dihydrogen onto the zeolites Na-ZSM-5 and K-ZSM-5 renders the fundamental H-H stretching mode infrared active. The corresponding infrared absorption bands were found at 4101 and 4112 cm-1 for H 2/Na-ZSM-5 and H2/K-ZSM-5, respectively. Thermodynamic characterization of the adsorbed state was carried out by means of variable-temperature infrared spectroscopy; simultaneously measuring integrated band intensity, temperature and equilibrium pressure of the gas phase. For the H2/Na-ZSM-5 system, the standard adsorption enthalpy and entropy resulted to be ΔH° = -10.3 (±0.5) kJ mol-1 and ΔS° = -121 (±10) J mol-1 K-1. For H 2/K-ZSM-5 corresponding values were -9.1 (±0.5) kJ mol -1 and -124 (±10) J mol-1 K-1, respectively.
Original language | English |
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Pages (from-to) | 247-252 |
Number of pages | 6 |
Journal | Microporous and Mesoporous Materials |
Volume | 80 |
Issue number | 1-3 |
DOIs | |
State | Published - 2005 |
ID: 13733546