0000000000268229
AUTHOR
Abby Kavner
Exploring the Chemical Reactivity between Carbon Dioxide and Three Transition Metals (Au, Pt, and Re) at High-Pressure, High-Temperature Conditions
The role of carbon dioxide, CO2, as oxidizing agent at high pressures and temperatures is evaluated by studying its chemical reactivity with three transition metals: Au, Pt, and Re. We report systematic X-ray diffraction measurements up to 48 GPa and 2400 K using synchrotron radiation and laser-heating diamond-anvil cells. No evidence of reaction was found in Au and Pt samples in this pressure–temperature range. In the Re + CO2 system, however, a strongly–driven redox reaction occurs at P > 8 GPa and T > 1500 K, and orthorhombic β-ReO2 is formed. This rhenium oxide phase is stable at least up to 48 GPa and 2400 K and was recovered at ambient conditions. Raman spectroscopy data confirm graph…
An Ultrahigh CO2-Loaded Silicalite-1 Zeolite: Structural Stability and Physical Properties at High Pressures and Temperatures
[EN] We report the formation of an ultrahigh CO2-loaded pure-SiO2, silicalite-1 structure at high pressure (0.7 GPa) from the interaction of empty zeolite and fluid CO, medium. The CO2-filled structure was characterized in situ by means of synchrotron powder X-ray diffraction. Rietveld refinements and Fourier recycling allowed the location of 16 guest carbon dioxide molecules per unit cell within the straight and sinusoidal channels of the porous framework to be analyzed. The complete filling of pores by CO, molecules favors structural stability under compression, avoiding pressure-induced amorphization below 20 GPa, and significantly reduces the compressibility of the system compared to th…
Structural evolution of CO2 filled pure silica LTA zeolite under high-pressure high-temperature conditions
[EN] The crystal structure of CO2-filled pure-SiO2 LTA zeolite has been studied at high pressures and temperatures using synchrotron-based X-ray powder diffraction. Its structure consists of 13 CO2 guest molecules, 12 of them accommodated in the large alpha-cages and one in the beta-cages, giving a SiO2/CO2 stoichiometric ratio smaller than 2. The structure remains stable under pressure up to 20 GPa with a slight pressure-dependent rhombohedral distortion, indicating that pressure-induced amorphization is prevented by the insertion of guest species in this open framework. The ambient temperature lattice compressibility has been determined. In situ high-pressure resistive-heating experiments…
Correspondence: Strongly-driven Re+CO2 redox reaction at high-pressure and high-temperature.
Correspondence: Strongly-driven Re+CO 2 redox reaction at high-pressure and high-temperature
Isothermal equation of state and phase stability of Fe 5 Si 3 up to 96 GPa and 3000 K
The composition of Earth's core has first-order implications for understanding the thermal and chemical history of the deep Earth. The present work measures the pressure-volume equation of state of Fe5Si3 to 96 GPa in a diamond anvil cell using noble gas pressure media and demonstrates that Fe5Si3 is not stable at high temperature and pressure, but reappears during thermal quench. The isothermal equation of state at ambient temperature of Fe5Si3 is given by the bulk modulus KT,0 = 167 (8) and KT,0' = 5.1 (2)), with V0 = 56.29 cm3mol-1. At high temperatures and pressures we observed the disappearance of hexagonal Fe5Si3 diffraction peaks and the appearance of peaks corresponding to cubic FeS…
CCDC 1827597: Experimental Crystal Structure Determination
Related Article: Tomas Marqueño, David Santamaria-Perez, Javier Ruiz-Fuertes, Raquel Chuliá-Jordán, Jose L. Jordá, Fernando Rey, Chris McGuire, Abby Kavner, Simon MacLeod, Dominik Daisenberger, Catalin Popescu, Placida Rodriguez-Hernandez, Alfonso Muñoz|2018|Inorg.Chem.|57|6447|doi:10.1021/acs.inorgchem.8b00523