Jump to main content
Jump to site search

Issue 6, 2018
Previous Article Next Article

Thermodynamic evidence of flexibility in H2O and CO2 absorption of transition metal ion exchanged zeolite LTA

Author affiliations

Abstract

Gas absorption calorimetry has been employed to probe the intercation of water and carbon dioxide with transition metal ion (TM = Mn2+, Fe2+, Co2+, Cu2+, and Zn2+) exchanged zeolite A samples. There appears to be a two-phase region, indicative of a guest-induced flexibility transition, separating hydrated zeolite A and its dehydrated form, both of which have variable water content in the single phase region. The differential enthalpy of absorption as a function of water loading directly identifies different strengths of multiple interactions along with possible binding mechanisms of Zn-A and Mn-A exhibiting the highest water absorption with most exothermic initial enthalpies of −125.28 ± 4.82 and –115.30 ± 2.56 kJ mol−1. Zn-A and Mn-A also show moderately good capture ability for CO2 with zero-coverage negative enthalpies of −55.59 ± 2.48 and −44.07 ± 1.53 kJ mol−1. The thermodynamic information derived from differential enthalpy, chemical potential and differential entropy elucidated the multistage interactive behavior of small guest molecules (H2O/CO2) and ion-exchanged frameworks.

Graphical abstract: Thermodynamic evidence of flexibility in H2O and CO2 absorption of transition metal ion exchanged zeolite LTA

Back to tab navigation

Supplementary files

Publication details

The article was received on 06 Dec 2017, accepted on 11 Jan 2018 and first published on 11 Jan 2018


Article type: Paper
DOI: 10.1039/C7CP08188J
Citation: Phys. Chem. Chem. Phys., 2018,20, 3970-3978
  •   Request permissions

    Thermodynamic evidence of flexibility in H2O and CO2 absorption of transition metal ion exchanged zeolite LTA

    X. Guo, L. Wu and A. Navrotsky, Phys. Chem. Chem. Phys., 2018, 20, 3970
    DOI: 10.1039/C7CP08188J

Search articles by author

Spotlight

Advertisements