Exploiting the adsorption of simple gases O2 and H2 with minimal quadrupole moments for the dual gas characterization of nanoporous carbons using 2D-NLDFT models

Jacek Jagiello (1) , Jeffrey Kenvin (1) , Conchi Maria Concepcion Ovin Ania (2) , José Parra (3) , Alain Celzard (4) , Vanessa Fierro (4)

1 MIC - Micromeritics Instrument Corporation
2 CEMHTI - Conditions Extrêmes et Matériaux : Haute Température et Irradiation
3 Instituto Nacional del Carbon
4 IJL - Institut Jean Lamour

For years, the characterization of carbon pore size distribution (PSD) has been dominated by the analysis of N2 isotherms. Recently, the IUPAC Technical Report (2015) recommended Ar as inert gas for this analysis. N2 molecule due to its significant quadrupole moment may selectively interact with the polar surface sites and affect the isotherm measurement. CO2, another gas that is often used for the characterization of microporous carbons exhibits even higher quadrupole moment than N2. In the present study, we substitute N2 and CO2 with O2 and H2 gases that have much lower quadrupole moments. The PSD calculations are performed using molecular models based on classical and quantum corrected two-dimensional nonlocal density functional theory (2D-NLDFT). We compare the results of the dual gas analysis methods by the simultaneous fit of our models to N2 & CO2, and O2 & H2 isotherms for several reference carbon samples and demonstrate consistency between the results derived from both pairs of isotherms. A fundamental and practical benefit of using the dual gas analysis method is the ability to obtain the full micro and mesopore PSD by using a partial O2 isotherm without low-pressure data in combination with full H2 isotherm both measured at 77 K.

Domaines: Ingénierie de l'environnement; Matériaux; Catalyse

Jacek Jagiello, Jeffrey Kenvin, Conchi Maria Concepcion Ovin Ania, José Parra, Alain Celzard, et al.. Exploiting the adsorption of simple gases O2 and H2 with minimal quadrupole moments for the dual gas characterization of nanoporous carbons using 2D-NLDFT models. Carbon, 2020, 160, pp.164-175. ⟨10.1016/j.carbon.2020.01.013⟩. ⟨hal-02612618⟩