skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Physisorption of CO 2 on non-ice materials relevant to icy satellites

Abstract

CO 2 is known to adsorb onto clay and other minerals when a significant atmospheric pressure is present. We have found that CO 2 can also adsorb onto some clays when the CO 2 partial pressure is effectively zero under ultra-high vacuum (UHV) if cooled to the surface temperatures of the icy satellites of Jupiter and Saturn. The strength of adsorption and the spectral characteristics of the adsorbed CO 2 infrared (IR) ν 3 absorption band near 4.25 μm depend on the composition and temperature of the adsorbent. CO 2 remains adsorbed onto the clay mineral montmorillonite for >10 s of min when exposed to a vacuum of ~1×10 -8 Torr at ~125 K. CO 2 does not adsorb onto serpentine, goethite, or palagonite under these conditions. A small amount may adsorb onto kaolinite. When heated above 150 K under vacuum, the CO 2 desorbs from the montmorillonite within a few minutes. The ν 3 absorption band of CO 2 adsorbed onto montmorillonite at 125 K is similar to that of the CO 2 detected on the saturnian and Galilean satellites and is markedly different from CO 2 adsorbed onto montmorillonite at room temperature. We infer the adsorption process ismore » physisorption and postulate that this mechanism may explain the presence and spectral characteristics of the CO 2 detected in the surfaces of these outer satellites.« less

Authors:
 [1];  [2]
  1. Johns Hopkins Univ., Baltimore, MD (United States)
  2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
922891
Report Number(s):
PNNL-SA-58793
Journal ID: ISSN 0019-1035; 19807; KP1704020; TRN: US200803%%464
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Icarus; Journal Volume: 191; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CARBON DIOXIDE; ADSORPTION; MONTMORILLONITE; PARTIAL PRESSURE; SATELLITES; JUPITER PLANET; SATURN PLANET; Environmental Molecular Sciences Laboratory

Citation Formats

Hibbitts, Charles A., and Szanyi, Janos. Physisorption of CO2 on non-ice materials relevant to icy satellites. United States: N. p., 2007. Web. doi:10.1016/j.icarus.2007.04.012.
Hibbitts, Charles A., & Szanyi, Janos. Physisorption of CO2 on non-ice materials relevant to icy satellites. United States. doi:10.1016/j.icarus.2007.04.012.
Hibbitts, Charles A., and Szanyi, Janos. Tue . "Physisorption of CO2 on non-ice materials relevant to icy satellites". United States. doi:10.1016/j.icarus.2007.04.012.
@article{osti_922891,
title = {Physisorption of CO2 on non-ice materials relevant to icy satellites},
author = {Hibbitts, Charles A. and Szanyi, Janos},
abstractNote = {CO2 is known to adsorb onto clay and other minerals when a significant atmospheric pressure is present. We have found that CO2 can also adsorb onto some clays when the CO2 partial pressure is effectively zero under ultra-high vacuum (UHV) if cooled to the surface temperatures of the icy satellites of Jupiter and Saturn. The strength of adsorption and the spectral characteristics of the adsorbed CO2 infrared (IR) ν3 absorption band near 4.25 μm depend on the composition and temperature of the adsorbent. CO2 remains adsorbed onto the clay mineral montmorillonite for >10 s of min when exposed to a vacuum of ~1×10-8 Torr at ~125 K. CO2 does not adsorb onto serpentine, goethite, or palagonite under these conditions. A small amount may adsorb onto kaolinite. When heated above 150 K under vacuum, the CO2 desorbs from the montmorillonite within a few minutes. The ν3 absorption band of CO2 adsorbed onto montmorillonite at 125 K is similar to that of the CO2 detected on the saturnian and Galilean satellites and is markedly different from CO2 adsorbed onto montmorillonite at room temperature. We infer the adsorption process is physisorption and postulate that this mechanism may explain the presence and spectral characteristics of the CO2 detected in the surfaces of these outer satellites.},
doi = {10.1016/j.icarus.2007.04.012},
journal = {Icarus},
number = 1,
volume = 191,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
  • In an oxyfuel plant, heat exchanging metallic components will be exposed to a flue gas that contains substantially higher contents of CO2, water vapor, and SO2 than conventionalflue gases. In the present study, the oxidation behavior of the martensitic steel P92 was studied in CO2-and/or H2O-rich gas mixtures with and without addition of SO2. For this purpose, the corrosion of P92 at 550 8C up to 1000 h in Ar–H2O–SO2, Ar–CO2–SO2, Ar–CO2–O2–SO2 and simulated oxyfuel gas (Ar–CO2–H2O–O2–SO2) was compared with the behavior in selected SO2-free gases. The oxidation kinetics were estimated by a number of methods such as optical microscopy,more » scanning electron microscopy with energy and wave length dispersive X-ray analysis, glow discharge optical emission spectroscopy, X-ray diffraction as well as transmission electron microscopy. The experimental results revealed that the effect of SO2 addition on the materials behavior substantially differed, depending on the prevailing base gas atmosphere. The various types of corrosion attack affected by SO2 could not be explained by solely comparing equilibrium activities of the gas atmospheres with thermodynamic stabilities of possible corrosion products. The results were found to be strongly affected by relative rates of reactions of the various gas species occurring within the frequently porous corrosion scales as well as at the scale/gas-and scale/alloy interfaces.Whereas SO2 addition to Ar–CO2 resulted in formation of an external mixed oxide/sulflde layer, the presence of SO2 in oxyfuel gas and in Ar–H2O–SO2 resulted in Fe-sulflde formation near the interface between inner and outer oxide layer as well as Cr-sulflde formation in the alloy. In the latter gases, the presence of SO2 seemed to have no dramatic effect on oxide scale growth rates.« less
  • Results are reported from experimental studies of the formation of ice mixed with mineral particles in an effort to simulate similar processes on natural surfaces such as at the Martian poles, on comet nuclei and on icy satellites. The study consisted of low-pressure, low-temperature sublimations of water ice from dilutions of water-clay (montmorillonite and Cabosil) dispersions of various component ratios. Liquid dispersions were sprayed into liquid nitrogen to form droplets at about -50 C. Both clay-water dispersions left a filamentary residue on the bottom of the Dewar after the water ice had sublimated off. The residue was studied with opticalmore » and SEM microscopy, the latter method revealing a high electrical conductivity in the residue. The results suggest that the sublimation of the water ice can leave a surface crust, which may be analogous to processes at the Martian poles and on comet nuclei. The process could proceed by the attachment of water molecules to salt crystals during the hottest part of the Martian year. The residue remaining was found to remain stable up to 370 C, be porous, and remain resilient, which could allow it to insulate ice bodies such as comets in space. 11 references.« less
  • In this paper, we explore the connections between resonance electron scattering by isolated and physisorbed molecules. The multiple scattering [ital X][alpha] method is used to calculate cross sections for electron scattering via the [sigma] shape resonances of O[sub 2], N[sub 2], and CO, near 9, 22, and 20 eV, respectively. Special emphasis is placed on the O[sub 2] resonance, for which no previous theoretical work has been reported. In all three cases, quantitative agreement is obtained with experimental gas phase scattering results. Angular distributions are then calculated for the isolated, oriented molecules, and compared with the angular distributions recently observedmore » in resonance scattering by O[sub 2], N[sub 2], and CO molecules oriented by physisorption on graphite. Characteristic nodes observed in each of the angular distributions are related to the calculated angular profiles, together with a previously proposed selection rule which we now formalize. This scheme allows the orientation of the molecules on the surface to be determined.« less
  • Carbon dioxide (CO{sub 2}) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν{sub 3} band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO{sub 2} band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present amore » rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H{sub 2}O)-carbon dioxide (CO{sub 2}) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν{sub 3} band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.« less
  • The reactions of Fe(CO){sub 3} with ethylene and H{sub 2} have been studied and rate constants for the formation of the H{sub 2}Fe(CO){sub 3} and Fe(CO){sub 3}(ethylene) complexes have been obtained. Further reactions of these unsaturated products with ethylene and H{sub 2} respectively have been shown to lead to formation of the H{sub 2}FE(CO){sub 3}(ethylene) complex which is a crucial intermediate in the proposed mechanism for Fe(CO){sub 3}-induced hydrogenation of ethylene. The rate constants for formation of this complex from both precursors have been obtained and are reported along with the other rate constants determined in this study. Interestingly, thoughmore » ethane is produced on a long time scale under the experimental conditions, H{sub 2}Fe(CO){sub 3}(ethylene) is stable at room temperature in the approximately 100-{mu}s observation time of these experiments. Significant differences have been observed for the rate constants of formation of the various complexes that were studied. These variations are discussed with respect to spin allowed versus disallowed reactions and the nature of the reacting ligand.« less