Catalytic effect of metal oxides on thermal decomposition reactions. II. Catalytic effect of metal oxides on the thermal decomposition of potassium chlorate and potassium perchlorate as detected by thermal analysis methods
01 Sep 1970-The Journal of Physical Chemistry (American Chemical Society)-Vol. 74, Iss: 18, pp 3317-3324
About: This article is published in The Journal of Physical Chemistry.The article was published on 1970-09-01. It has received 83 citations till now. The article focuses on the topics: Potassium chlorate & Thermal decomposition.
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Douglas W. Ming, P. D. Archer, Daniel P. Glavin1, Jennifer L. Eigenbrode1 +439 more•Institutions (55)
TL;DR: Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the Mudstone; however, the carbon source for the chlorinatedHydrocarbons is not definitively of martian origin.
Abstract: H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.
349 citations
Cites background from "Catalytic effect of metal oxides on..."
...Chlorate salts may also be stable on the martian surface (27), and mixtures of K-chlorate and hematite can decompose at temperatures consistent with O2-release temperatures observed in JK and CB (26)....
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...3C), the presence of Fe-oxides/oxyhydroxides may lower the decomposition temperature of perchlorate salts (26)....
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Jacobs Engineering Group1, Goddard Space Flight Center2, Centre national de la recherche scientifique3, California Institute of Technology4, Carnegie Institution for Science5, Pennsylvania State University6, National Autonomous University of Mexico7, Arizona State University8, University of Guelph9, University of New Brunswick10
TL;DR: The Sample Analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, H2, SO2, H 2S, NO, CO2, CO, O2 and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater.
Abstract: The Sample Analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, H2, SO2, H2S, NO, CO2, CO, O2 and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater, Mars. These evolved gas detections indicate nitrates, organics, oxychlorine phase, and sulfates are widespread with phyllosilicates and carbonates occurring in select Gale Crater materials. Coevolved CO2 (160 ± 248 - 2373 ± 820 μgC(CO2)/g), and CO (11 ± 3 - 320 ± 130 μgC(CO)/g) suggest organic-C is present in Gale Crater materials. Five samples evolved CO2 at temperatures consistent with carbonate (0.32± 0.05 - 0.70± 0.1 wt.% CO3). Evolved NO amounts to 0.002 ± 0.007 - 0.06 ± 0.03 wt.% NO3. Evolution of O2 suggests oxychlorine phases (chlorate/perchlorate) (0.05 ± 0.025 - 1.05 ± 0.44wt. % ClO4) are present while SO2 evolution indicates the presence of crystalline and/or poorly crystalline Fe- and Mg-sulfate and possibly sulfide. Evolved H2O (0.9 ± 0.3 - 2.5 ± 1.6 wt.% H2O) is consistent with the presence of adsorbed water, hydrated salts, interlayer/structural water from phyllosilicates, and possible inclusion water in mineral/amorphous phases. Evolved H2 and H2S suggest reduced phases occur despite the presence of oxidized phases (nitrate, oxychlorine, sulfate, carbonate). SAM results coupled with CheMin mineralogical and APXS elemental analyses indicate that Gale Crater sedimentary rocks have experienced a complex authigenetic/diagenetic history involving fluids with varying pH, redox, and salt composition. The inferred geochemical conditions were favorable for microbial habitability and if life ever existed, there was likely sufficient organic-C to support a small microbial population.
160 citations
06 Jan 2019
TL;DR: The Sample Analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, SO2, NO, CO2, CO, O2, and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater, Mars as mentioned in this paper.
Abstract: The Sample Analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, SO2, NO, CO2, CO, O2, and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater, Mars. The SAM-EGA heats samples to 870°C and measures evolved gas releases as function of temperature. These evolved gas detections indicate nitrates, organics, oxychlorine phase, and sulfates are widespread with phyllosilicates and carbonates occurring in select Gale Crater materials. CO2 and CO evolved at similar temperatures suggesting that as much as 2373 ± 820 μgC/g may occur as organic carbon in the Gale Crater rock record while relatively higher temperature CO2 detections are consistent with carbonate (<0.70 ± 0.1 wt % CO3). Evolved NO amounts up to 0.06 ± 0.03 wt % NO3 have been detected while O2 detections suggests chlorates and/or perchlorates (0.05 to 1.05 wt % ClO4) are present. Evolution of SO2 indicated the presence of crystalline and/or poorly crystalline Fe and Mg sulfate and possibly sulfide. Evolved H2O (0.9 - 2.5 wt% H2O) was consistent with the presence of adsorbed water, hydrated salts, interlayer/structural water from phyllosilicates, and possible inclusion water in mineral/amorphous phases. Evolved H2S detections suggest that reduced phases occur despite the presence of oxidized phases (nitrate, oxychlorine, sulfate, and carbonate). SAM results coupled with CheMin mineralogical and Alpha-Particle X-ray Spectrometer elemental analyses indicate that Gale Crater sedimentary rocks have experienced a complex authigenetic/diagenetic history involving fluids with varying pH, redox, and salt composition. The inferred geochemical conditions were favorable for microbial habitability and if life ever existed, there was likely sufficient organic C to support a small microbial population.
130 citations
TL;DR: In this article, the effect of TMO catalysts on solid propellant burning and decomposition, oxidizer burning, and sandwich and condensed mixture combustion is discussed. But, the exact mechanism of the effect on the burning rate modification of composite solid propellants is not clear even today.
Abstract: Introduction T metal oxides (TMO) like Fe2O3, CuO, MnO2, CuCr2O4, etc., form a very popular group of catalysts for burning rate modification of composite solid propellants. Although it is well known that these oxides affect the decomposition characteristics of polymers and oxidizers like ammonium perchlorate (AP)' and potassium perchlorate, (KP) the exact mechanism of the effect on solid propellants is by no means clear even today. Much fragmentary literature is available on the effect of these oxides on propellant burning and decomposition, oxidizer burning and decomposition, and sandwich and condensed mixture combustion. It is the purpose of this review to bring the material together so that a comprehensive picture can be drawn of the mechanism of the action of these catalysts. It may be mentioned here that these oxides also catalyze hydrocarbon oxidation reactions by inducing free radical decomposition of hydroperoxides (formed by the contact of oxidizer and hydrocarbon).
91 citations
TL;DR: An insight is provided into the oxidizing potential of the surface of Mars and an estimate of the stability of organic matter in an oxidizing environment is provided.
Abstract: In 1976, the Viking landers carried out the most comprehensive search for organics and microbial life in the martian regolith. Their results indicate that Mars' surface is lifeless and, surprisingly, depleted in organics at part-per-billion levels. Several biology experiments on the Viking landers gave controversial results that have since been explained by the presence of oxidizing agents on the surface of Mars. These oxidants may degrade abiotic or biological organics, resulting in their nondetection in the regolith. As several exploration missions currently focus on the detection of organics on Mars (or will do so in the near future), knowledge of the oxidative state of the surface is fundamental. It will allow for determination of the capability of organics to survive on a geological timescale, the most favorable places to seek them, and the best methods to process the samples collected at the surface. With this aim, we review the main oxidants assumed to be present on Mars, their possible fo...
79 citations
Cites background from "Catalytic effect of metal oxides on..."
...Iron-bearing minerals can catalyze the oxidation and/or chlorination of organic molecules with the fragments formed by the thermal decomposition of perchlorates (Rudloff and Freeman, 1970; Navarro-González et al., 2006; Vollhardt and Schore, 2009)....
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...Iron-bearing minerals can catalyze the oxidation and/or chlorination of organic molecules with the fragments formed by the thermal decomposition of perchlorates (Rudloff and Freeman, 1970; Navarro-González et al., 2006; Vollhardt and Schore, 2009)....
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