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Title: Feedbacks among O 2 and CO 2 in deep soil gas, oxidation of ferrous minerals, and fractures: A hypothesis for steady-state regolith thickness

Authors:
; ORCiD logo;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1396578
Grant/Contract Number:
FG02-05ER15675
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Earth and Planetary Science Letters
Additional Journal Information:
Journal Volume: 460; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 09:30:19; Journal ID: ISSN 0012-821X
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Kim, Hyojin, Stinchcomb, Gary, and Brantley, Susan L. Feedbacks among O 2 and CO 2 in deep soil gas, oxidation of ferrous minerals, and fractures: A hypothesis for steady-state regolith thickness. Netherlands: N. p., 2017. Web. doi:10.1016/j.epsl.2016.12.003.
Kim, Hyojin, Stinchcomb, Gary, & Brantley, Susan L. Feedbacks among O 2 and CO 2 in deep soil gas, oxidation of ferrous minerals, and fractures: A hypothesis for steady-state regolith thickness. Netherlands. doi:10.1016/j.epsl.2016.12.003.
Kim, Hyojin, Stinchcomb, Gary, and Brantley, Susan L. Wed . "Feedbacks among O 2 and CO 2 in deep soil gas, oxidation of ferrous minerals, and fractures: A hypothesis for steady-state regolith thickness". Netherlands. doi:10.1016/j.epsl.2016.12.003.
@article{osti_1396578,
title = {Feedbacks among O 2 and CO 2 in deep soil gas, oxidation of ferrous minerals, and fractures: A hypothesis for steady-state regolith thickness},
author = {Kim, Hyojin and Stinchcomb, Gary and Brantley, Susan L.},
abstractNote = {},
doi = {10.1016/j.epsl.2016.12.003},
journal = {Earth and Planetary Science Letters},
number = C,
volume = 460,
place = {Netherlands},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.epsl.2016.12.003

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  • Steady state experiments and their interpretation were performed to explore the kinetics of CO oxidation over a supported Co/sub 3/O/sub 4/ catalyst. The rate of reaction was found to depend on temperature and the partial pressure of oxygen but not on the partial pressure of carbon monoxide. It is shown that catalyst dynamics must be accounted for to achieve real understanding.
  • Cited by 9
  • The velocity distribution of desorbing CO{sub 2} was studied in steady-state CO oxidation on Pd(110) in a wide range of both surface temperature and reactant pressure by means of cross-correlation time-of-flight techniques. The velocity distribution curve always involved two components (fast and slow). The slow component showed a Maxwellian velocity distribution at the surface temperature. The energy of the fast component increased with increasing ratio of oxygen to CO pressure from 2,200 to 4,000 K, suggesting compressed oxygen lattices enhancing the velocity. This component was abruptly suppressed at the critical CO pressure, where the rate-determining step switched from CO adsorptionmore » to oxygen dissociation. The energy of the fast component increased with increasing surface temperature, suggesting a change in the energy partition itself. Above about 3 x 10{sup {minus}4} Torr of O{sub 2}, the slow component did not become predominant even far above the critical pressure of CO.« less
  • Cited by 18
  • The kinetic rates for CO oxidation have been measured in a high pressure/ultra-high vacuum surface analysis chamber over the temperature range of 443-673 K and the pressure range of 0.3-108 Torr. An Arrhenius activation energy of 22 kcal/mole was measured for CO oxidation at the Pd(100) single crystal surface. Furthermore, the reaction order for the CO was found to decrease from {minus}0.2 to {minus}0.9 as the pressure was lowered from 16 to 1 Torr CO, and the O{sub 2} reaction order was found to increase from 0.6 to 1.0 at CO pressures of 16 and 1 Torr, respectively. These changesmore » are attributed to the dramatic variation in heat of adsorption seen on the Pd(100) surface (34 to less than 20 kcal/mole at saturation coverage (nonlinear function)). The kinetic behavior of the c(2 {times} 2)-Sn/Pd(100) bimetallic surface alloy was similarly studied and the activation energy for the CO oxidation reaction was found to be 12 kcal/mole. The surface alloy was ascertained to have catalytic reaction orders for CO and O{sub 2} of 0.2 and 0.1, respectively. This is attributed to an increase in the oxygen surface coverage in the form of SnO{sub x} (x = 1-2) atop the Pd(100) template. Possible roles that the SnO{sub x} plays in accelerating this reaction are suggested. The surfaces were also characterized by Auger electron spectroscopy, low energy electron diffraction, and thermal desorption mass spectroscopy prior to and following high pressure catalytic reactions.« less