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Kirill Kovnir - One of the best experts on this subject based on the ideXlab platform.

  • high efficiency thermoelectric ba8cu14ge6p26 bridging the gap between tetrel based and tetrel free Clathrates
    Chemical Science, 2017
    Co-Authors: Jian Wang, Julianna Dolyniuk, Kathleen Lee, Kirill Kovnir, Oleg I. Lebedev, Peter Klavins, Sabah Bux
    Abstract:

    A new type-I clathrate, Ba8Cu14Ge6P26, was synthesized by solid-state methods as a polycrystalline powder and grown as a cm-sized single crystal via the vertical Bridgman method. Single-crystal and powder X-ray diffraction show that Ba8Cu14Ge6P26 crystallizes in the cubic space group Pm3n (no. 223). Ba8Cu14Ge6P26 is the first representative of anionic Clathrates whose framework is composed of three atom types of very different chemical natures: a transition metal, tetrel element, and pnicogen. Uniform distribution of the Cu, Ge, and P atoms over the framework sites and the absence of any superstructural or local ordering in Ba8Cu14Ge6P26 were confirmed by synchrotron X-ray diffraction, electron diffraction and high-angle annular dark field scanning transmission electron microscopy, and neutron and X-ray pair distribution function analyses. Characterization of the transport properties demonstrate that Ba8Cu14Ge6P26 is a p-type semiconductor with an intrinsically low thermal conductivity of 0.72 W m-1 K-1 at 812 K. The thermoelectric figure of merit, ZT, for a slice of the Bridgman-grown crystal of Ba8Cu14Ge6P26 approaches 0.63 at 812 K due to a high power factor of 5.62 μW cm-1 K-2. The thermoelectric efficiency of Ba8Cu14Ge6P26 is on par with the best optimized p-type Ge-based Clathrates and outperforms the majority of Clathrates in the 700-850 K temperature region, including all tetrel-free Clathrates. Ba8Cu14Ge6P26 expands clathrate chemistry by bridging conventional tetrel-based and tetrel-free Clathrates. Advanced transport properties, in combination with earth-abundant framework elements and congruent melting make Ba8Cu14Ge6P26 a strong candidate as a novel and efficient thermoelectric material.

  • High-efficiency thermoelectric Ba8Cu14Ge6P26 bridging the gap between tetrel-based and tetrel-free Clathrates
    Chemical Science, 2017
    Co-Authors: Jian Wang, Julianna Dolyniuk, Kathleen Lee, Oleg I. Lebedev, Peter Klavins, Sabah Bux, Kirill Kovnir
    Abstract:

    A new type-I clathrate, Ba8Cu14Ge6P26, was synthesized by solid-state methods as a polycrystalline powder and grown as a cm-sized single crystal via the vertical Bridgman method. Single-crystal and powder X-ray diffraction show that Ba8Cu14Ge6P26 crystallizes in the cubic space group Pm (3) over barn (no. 223). Ba8Cu14Ge6P26 is the first representative of anionic Clathrates whose framework is composed of three atom types of very different chemical natures a transition metal, tetrel element, and pnicogen. Uniform distribution of the Cu, Ge, and P atoms over the framework sites and the absence of any superstructural or local ordering in Ba8Cu14Ge6P26 were confirmed by synchrotron X-ray diffraction, electron diffraction and high-angle annular dark field scanning transmission electron microscopy, and neutron and X-ray pair distribution function analyses. Characterization of the transport properties demonstrate that Ba8Cu14Ge6P26 is a p-type semiconductor with an intrinsically low thermal conductivity of 0.72 W m(-1) K-1 at 812 K. The thermoelectric figure of merit, ZT, for a slice of the Bridgman-grown crystal of Ba8Cu14Ge6P26 approaches 0.63 at 812 K due to a high power factor of 5.62 mu W cm(-1) K-2. The thermoelectric efficiency of Ba8Cu14Ge6P26 is on par with the best optimized p-type Ge-based Clathrates and outperforms the majority of Clathrates in the 700-850 K temperature region, including all tetrel-free Clathrates. Ba8Cu14Ge6P26 expands clathrate chemistry by bridging conventional tetrel-based and tetrel-free Clathrates. Advanced transport properties, in combination with earth-abundant framework elements and congruent melting make Ba8Cu14Ge6P26 a strong candidate as a novel and efficient thermoelectric material.

  • twisted kelvin cells and truncated octahedral cages in the crystal structures of unconventional Clathrates am2p4 a sr ba m cu ni
    Chemistry of Materials, 2015
    Co-Authors: Julianna Dolyniuk, Jian Wang, Kathleen Lee, Kirill Kovnir
    Abstract:

    A new strontium nickel polyphosphide, SrNi2P4, was synthesized from elements and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Fddd (No. 70), with Z = 8. The crystal structure is that of a clathrate type, composed of Ni8P16, 14-faced polyhedral cages that encapsulate Sr atoms. Together with the previously reported but unrecognized clathrate VII, BaNi2P4, and another previously reported clathrate, BaCu2P4, which is isostructural to SrNi2P4, a family of transition metal–phosphorus Clathrates is represented. The crystal structures of each of the discussed transition metal-based Clathrates are composed of unique polyhedra containing square faces. These structural fragments were predicted to be unstable for the conventional Clathrates based on Si, Ge, and Sn. In this work, we report the crystal and electronic structures, chemical bonding, as well as the thermoelectric properties of this novel class of unconventional Clathrates.

Ji-ho Yoon - One of the best experts on this subject based on the ideXlab platform.

  • Spectroscopic identification and conversion rate of gaseous guest-loaded hydroquinone Clathrates
    Chemical Physics Letters, 2012
    Co-Authors: Jong-won Lee, Ki Jong Choi, Yongjae Lee, Ji-ho Yoon
    Abstract:

    Abstract The formation of hydroquinone Clathrates with CO 2 , CH 4 , N 2 , and H 2 was investigated using X-ray diffraction, Raman spectroscopy, and solid-state 13 C NMR spectroscopy. Of the hydroquinones prepared at 5.0 MPa, the CH 4 - and CO 2 -loaded hydroquinones show complete conversion to β-form hydroquinone Clathrates while the N 2 -loaded hydroquinone shows only partial conversion; there is no indication of the formation of hydroquinone clathrate with H 2 . The CO 2 -loaded hydroquinone is fully converted to the β-form hydroquinone clathrate even at 1.0 MPa. Solid-state 13 C NMR measurements of the hydroquinone clathrate samples prepared at different pressures reveal that the conversion rate for the formation of clathrate compounds from CH 4 and N 2 decreases with decreasing pressure.

  • Characterization of hydroquinone Clathrates by THz time-domain spectroscopy
    2009 34th International Conference on Infrared Millimeter and Terahertz Waves, 2009
    Co-Authors: Ji-ho Yoon, Jin-seok Jang, Tae-in Jeon
    Abstract:

    Using terahertz time-domain spectroscopy (THz-TDS), we have measured the absorption spectra of α-hydroquinone and methane- and methanol-loaded β-hydroquinone Clathrates up to 3 THz frequency range. The α-hydroquinone exhibits 11 resonances whereas methane- and methanol-loaded β-hydroquinone Clathrates show only 1 resonance. The observed THz resonances represent the intermolecular and lattice vibrations of the hydroquinone frameworks, but seem to be insensitive to the encaged guest species. The indices of refraction are found to be ca. 1.6 for α-hydroquinone and methane-loaded β-hydroquinone clathrate and 1.7 for methanol-loaded β-hydroquinone clathrate, and the anomalous dispersions are well defined at the resonance frequencies.

  • Characterization of α-hydroquinone and β-hydroquinone Clathrates by THz time-domain spectroscopy
    Chemical Physics Letters, 2009
    Co-Authors: Jin-seok Jang, Tae-in Jeon, Ji-ho Yoon
    Abstract:

    Abstract We have measured the absorption spectra of α-hydroquinone and methane- and methanol-loaded β-hydroquinone Clathrates up to 3 THz frequency range using terahertz time-domain spectroscopy (THz-TDS). The α-hydroquinone exhibits 11 resonances whereas methane- and methanol-loaded β-hydroquinone Clathrates show only 1 resonance. The observed THz resonances represent the intermolecular and lattice vibrations of the hydroquinone frameworks, but seem to be insensitive to the encaged guest species. The indices of refraction are found to be ca. 1.6 for α-hydroquinone and methane-loaded β-hydroquinone clathrate and 1.7 for methanol-loaded β-hydroquinone clathrate, and the anomalous dispersions are well-defined at the resonance frequencies.

Jeanphilippe Torre - One of the best experts on this subject based on the ideXlab platform.

  • insights into the crystal structure and clathration selectivity of organic Clathrates formed with hydroquinone and co2 ch4 gas mixtures
    Journal of Physical Chemistry C, 2019
    Co-Authors: Jeanphilippe Torre, Christophe Dicharry, Romuald Coupan, Heinz Gornitzka, Antonio Comesaña, Martin Perezrodriguez, Manuel M. Piñeiro
    Abstract:

    Organic Clathrates, particularly those formed by hydroquinone (HQ) and gas mixtures, have been far less studied than other inclusion compounds, such as gas hydrates. In this study, experiments and molecular dynamics simulations were performed on mixed (CO2 + CH4)–HQ Clathrates. Single crystals were synthesized using gas mixtures with different compositions, ranging from pure CO2 to pure CH4. The crystal structure, the guest occupancy in the Clathrates, and the variation of the crystal lattice parameters according to clathrate composition were obtained by X-ray diffraction measurements. In addition, molecular dynamics simulations were performed on the same systems, with state-of-the-art molecular models and force fields. The experimental results obtained and the molecular dynamics simulation estimations were in good agreement. The clathration selectivity was also calculated on the basis of experimental results, and the composition of the solid phase was correlated with the composition of the gas phase at e...

  • Insights into the Crystal Structure and Clathration Selectivity of Organic Clathrates Formed with Hydroquinone and (CO2 + CH4) Gas Mixtures
    Journal of Physical Chemistry C, 2019
    Co-Authors: Jeanphilippe Torre, Christophe Dicharry, Romuald Coupan, Heinz Gornitzka, Martín Pérez-rodríguez, Antonio Comesaña, Manuel M. Piñeiro
    Abstract:

    Organic Clathrates, particularly those formed by hydroquinone (HQ) and gas mixtures, have been far less studied than other inclusion compounds, such as gas hydrates. In this study, experiments and molecular dynamics simulations were performed on mixed (CO2 + CH4)–HQ Clathrates. Single crystals were synthesized using gas mixtures with different compositions, ranging from pure CO2 to pure CH4. The crystal structure, the guest occupancy in the Clathrates, and the variation of the crystal lattice parameters according to clathrate composition were obtained by X-ray diffraction measurements. In addition, molecular dynamics simulations were performed on the same systems, with state-of-the-art molecular models and force fields. The experimental results obtained and the molecular dynamics simulation estimations were in good agreement. The clathration selectivity was also calculated on the basis of experimental results, and the composition of the solid phase was correlated with the composition of the gas phase at equilibrium. These new insights into these structures will be useful from both a fundamental and a practical point of view, particularly for further developing innovative gas separation techniques using HQ Clathrates.

  • Phase equilibrium properties of CO 2 /CH 4 mixed gas hydroquinone Clathrates: Experimental data and model predictions
    Journal of Chemical Thermodynamics, 2018
    Co-Authors: Romuald Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe Torre
    Abstract:

    Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO2/CH4 gas mixtures. The clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO2/CH4 gas mixture in the clathrate and in the gas phase. The results obtained reveal that CH4 molecules in the CO2/CH4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of clathrate phase equilibria.

  • phase equilibrium properties of co 2 ch 4 mixed gas hydroquinone Clathrates experimental data and model predictions
    The Journal of Chemical Thermodynamics, 2018
    Co-Authors: Romuald Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe Torre
    Abstract:

    Abstract Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO 2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO 2 /CH 4 gas mixtures. The clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO 2 /CH 4 gas mixture in the clathrate and in the gas phase. The results obtained reveal that CH 4 molecules in the CO 2 /CH 4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of clathrate phase equilibria.

  • new insights on gas hydroquinone Clathrates using in situ raman spectroscopy formation dissociation mechanisms kinetics and capture selectivity
    Journal of Physical Chemistry A, 2017
    Co-Authors: Romuald Coupan, Christophe Dicharry, Eve Pere, Jeanphilippe Torre
    Abstract:

    Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highli...

Christophe Dicharry - One of the best experts on this subject based on the ideXlab platform.

  • insights into the crystal structure and clathration selectivity of organic Clathrates formed with hydroquinone and co2 ch4 gas mixtures
    Journal of Physical Chemistry C, 2019
    Co-Authors: Jeanphilippe Torre, Christophe Dicharry, Romuald Coupan, Heinz Gornitzka, Antonio Comesaña, Martin Perezrodriguez, Manuel M. Piñeiro
    Abstract:

    Organic Clathrates, particularly those formed by hydroquinone (HQ) and gas mixtures, have been far less studied than other inclusion compounds, such as gas hydrates. In this study, experiments and molecular dynamics simulations were performed on mixed (CO2 + CH4)–HQ Clathrates. Single crystals were synthesized using gas mixtures with different compositions, ranging from pure CO2 to pure CH4. The crystal structure, the guest occupancy in the Clathrates, and the variation of the crystal lattice parameters according to clathrate composition were obtained by X-ray diffraction measurements. In addition, molecular dynamics simulations were performed on the same systems, with state-of-the-art molecular models and force fields. The experimental results obtained and the molecular dynamics simulation estimations were in good agreement. The clathration selectivity was also calculated on the basis of experimental results, and the composition of the solid phase was correlated with the composition of the gas phase at e...

  • Insights into the Crystal Structure and Clathration Selectivity of Organic Clathrates Formed with Hydroquinone and (CO2 + CH4) Gas Mixtures
    Journal of Physical Chemistry C, 2019
    Co-Authors: Jeanphilippe Torre, Christophe Dicharry, Romuald Coupan, Heinz Gornitzka, Martín Pérez-rodríguez, Antonio Comesaña, Manuel M. Piñeiro
    Abstract:

    Organic Clathrates, particularly those formed by hydroquinone (HQ) and gas mixtures, have been far less studied than other inclusion compounds, such as gas hydrates. In this study, experiments and molecular dynamics simulations were performed on mixed (CO2 + CH4)–HQ Clathrates. Single crystals were synthesized using gas mixtures with different compositions, ranging from pure CO2 to pure CH4. The crystal structure, the guest occupancy in the Clathrates, and the variation of the crystal lattice parameters according to clathrate composition were obtained by X-ray diffraction measurements. In addition, molecular dynamics simulations were performed on the same systems, with state-of-the-art molecular models and force fields. The experimental results obtained and the molecular dynamics simulation estimations were in good agreement. The clathration selectivity was also calculated on the basis of experimental results, and the composition of the solid phase was correlated with the composition of the gas phase at equilibrium. These new insights into these structures will be useful from both a fundamental and a practical point of view, particularly for further developing innovative gas separation techniques using HQ Clathrates.

  • Phase equilibrium properties of CO 2 /CH 4 mixed gas hydroquinone Clathrates: Experimental data and model predictions
    Journal of Chemical Thermodynamics, 2018
    Co-Authors: Romuald Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe Torre
    Abstract:

    Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO2/CH4 gas mixtures. The clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO2/CH4 gas mixture in the clathrate and in the gas phase. The results obtained reveal that CH4 molecules in the CO2/CH4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of clathrate phase equilibria.

  • phase equilibrium properties of co 2 ch 4 mixed gas hydroquinone Clathrates experimental data and model predictions
    The Journal of Chemical Thermodynamics, 2018
    Co-Authors: Romuald Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe Torre
    Abstract:

    Abstract Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO 2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO 2 /CH 4 gas mixtures. The clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO 2 /CH 4 gas mixture in the clathrate and in the gas phase. The results obtained reveal that CH 4 molecules in the CO 2 /CH 4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of clathrate phase equilibria.

  • New Insights on Gas Hydroquinone Clathrates Using in Situ Raman Spectroscopy: Formation/Dissociation Mechanisms, Kinetics, and Capture Selectivity
    Journal of Physical Chemistry A, 2017
    Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, J.-p. Torré
    Abstract:

    Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highlighted the presence of a clathrate structure with no guest molecules. We can therefore conclude that HQ clathrate formation and dissociation are two-step reactions that pass through two distinct reaction intermediates: guest-loaded α-HQ and guest-free β-HQ. When an equimolar CO2/CH4 gas mixture is put in contact with either the α-HQ or the guest-free β-HQ, the CO2 is preferentially captured. Moreover, the guest-free β-HQ can retain the CO2 quicker and more selectively.

J.-p. Torré - One of the best experts on this subject based on the ideXlab platform.

  • New Insights on Gas Hydroquinone Clathrates Using in Situ Raman Spectroscopy: Formation/Dissociation Mechanisms, Kinetics, and Capture Selectivity
    Journal of Physical Chemistry A, 2017
    Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, J.-p. Torré
    Abstract:

    Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highlighted the presence of a clathrate structure with no guest molecules. We can therefore conclude that HQ clathrate formation and dissociation are two-step reactions that pass through two distinct reaction intermediates: guest-loaded α-HQ and guest-free β-HQ. When an equimolar CO2/CH4 gas mixture is put in contact with either the α-HQ or the guest-free β-HQ, the CO2 is preferentially captured. Moreover, the guest-free β-HQ can retain the CO2 quicker and more selectively.

  • Experimental Determination of Phase Equilibria and Occupancies for CO2, CH4, and N2 Hydroquinone Clathrates
    Journal of Chemical and Engineering Data, 2016
    Co-Authors: R. Coupan, M. Chabod, Christophe Dicharry, Joseph Diaz, Christelle Miqueu, J.-p. Torré
    Abstract:

    Hydroquinone (HQ) forms organic Clathrates in the presence of various gas molecules in specific thermodynamic conditions. For some systems, clathrate phase equilibrium and occupancy data are very scarce or inexistent in literature to date. This work presents experimental results obtained for the CO2–HQ, CH4–HQ, and N2–HQ Clathrates, in an extended range of temperature from about 288 to 354 K. Formation/dissociation pressures, and occupancies at the equilibrium clathrate forming conditions, were determined for these systems. Experiments showing the influence of the crystallization solvent, and the effect of the gas pressure on HQ solubility, were also presented and discussed. A good agreement is obtained between our experimental results and the already published experimental and modeling data. Our results show a clear dependency of the clathrate occupancy with temperature. The equilibrium curves obtained for CO2–HQ and CH4–HQ Clathrates were found to be very close to each other. The results presented in this study, obtained in a relatively large temperature range, are new and important to the field of organic Clathrates with potential impact on gas separation, energy storage, and transport.

  • Revisiting the thermodynamic modelling of type I gas–hydroquinone Clathrates
    Physical Chemistry Chemical Physics, 2016
    Co-Authors: M.m. Conde, J.-p. Torré, Christelle Miqueu
    Abstract:

    Under specific pressure and temperature conditions, certain gaseous species can be engaged in a host lattice of hydroquinone molecules, forming a supramolecular entity called a gas hydroquinone clathrate. This study is devoted to the thermodynamic modelling of type I hydroquinone Clathrates. The gases considered in this work are argon, krypton, xenon, methane, nitrogen, oxygen and hydrogen sulphide. The basic van der Waals and Platteeuw model, which is, for example, not able to predict well the phase equilibrium properties of such Clathrates at high temperature, is modified and extended by considering first the solubility of the guest in solid HQ and then the mutual interactions between the gaseous molecules inside the clathrate structure (i.e. guest–guest interactions). Other improvements of the basic theory, such as the choice of the reference state, are proposed, and a unique set of thermodynamic parameters valid for all the studied guests are finally calculated. Very good agreement is obtained between the model predictions and the experimental data available in the literature. Our results clearly demonstrate that the highest level of theory is necessary to describe well both the triphasic equilibrium line (where the HQ clathrate, the native hydroquinone HQα and the gas coexist), the occupancy of the guest in the clathrate, and the intercalation enthalpy.