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Direct Determination of Enthalpies of Sorption Using Pressure‐Gradient Differential Scanning Calorimetry: CO 2 Sorption by Cu‐HKUST
Author(s) -
Feldmann Wesley K.,
White KerryAnne,
Bezuidenhout Charl X.,
Smith Vincent J.,
Esterhuysen Catharine,
Barbour Leonard J.
Publication year - 2020
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201902990
Subject(s) - sorption , differential scanning calorimetry , enthalpy , calorimetry , chemistry , thermodynamics , metal organic framework , analytical chemistry (journal) , materials science , chromatography , adsorption , physics
Enthalpy of sorption (Δ H ) is an important parameter for the design of separation processes using adsorptive materials. A pressure‐ramped calorimetric method is described and tested for the direct determination of Δ H values. Combining a heatflow thermogram with a single sorption isotherm enables the determination of Δ H as a function of loading. The method is validated by studying CO 2 sorption by the well‐studied metal–organic framework Cu‐HKUST over a temperature range of 288–318 K. The measured Δ H values compare well with previously reported data determined by using isosteric and calorimetric methods. The pressure‐gradient differential scanning calorimetry (PGDSC) method produces reliable high‐resolution results by direct measurement of the enthalpy changes during the sorption processes. Additionally, PGDSC is less labor‐intensive and time‐consuming than the isosteric method and offers detailed insight into how Δ H changes over a given loading range.