REACTIONS IN DISSOCIATED PEROXIDE VAPOR

1953 ◽  
Vol 31 (3) ◽  
pp. 262-271 ◽  
Author(s):  
J. S. Batzold ◽  
C. Luner ◽  
C. A. Winkler
Keyword(s):  
Hydrogen Peroxide ◽  
Water Vapor ◽  
Electrical Discharge ◽  
Molecular Hydrogen ◽  
Volume Ratio ◽  
Cold Trap ◽  
Gas Phase Reactions ◽  
Hydrogen Atoms ◽  
A Chain ◽  
Hydrogen Peroxide Vapor

The products of the electrical discharge through hydrogen peroxide vapor were hydrogen peroxide, water, oxygen, and hydrogen, in amounts which depended upon the arrangement and temperature of the trap, reaction time, and surface to volume ratio of the reaction vessel. Water, hydrogen, and oxygen resulted from the gas phase reactions of the dissociated hydrogen peroxide, with hydrogen peroxide produced only in a trap cooled below −120 °C. Products trapped below −150 °C evolved oxygen on warming to room temperature. The decomposition products of the electrical discharge through hydrogen peroxide correspond closely with products obtainable both from a similar discharge through water vapor and from the interaction of hydrogen atoms with oxygen molecules in a cold trap. A mechanism which accounts for their correspondence is included. Water was the only product when molecular hydrogen peroxide was caused to react with hydrogen atoms, dissociated hydrogen peroxide vapor, or dissociated water vapor in the presence or absence of molecular hydrogen. A chain mechanism is postulated for these reactions.

Studies on Hydrogen–Oxygen Systems in the Electrical Discharge. VII. Deuterium Isotope Effects in the Chemistry of the Hydrogen Polyoxides

1975 ◽  
Vol 53 (16) ◽  
pp. 2490-2497 ◽  
Author(s):  
José L. Arnau ◽  
Paul A. Giguère
Keyword(s):  
Hydrogen Peroxide ◽  
Electrical Discharge ◽  
Microwave Discharge ◽  
Isotope Effects ◽  
Cold Trap ◽  
Manometric Method ◽  
Deuterium Isotope Effects ◽  
Kinetics Of ◽  
Hydrogen Polyoxides ◽  
Hydrogen Peroxide Vapor

The kinetics of oxygen evolution on warming the trapped products (at −196 °C) from water or hydrogen peroxide vapor dissociated in a glow discharge were studied by the manometric method. Under closely controlled conditions it was possible to distinguish clearly the decomposition of the two intermediates, H2O3 and H2O4. The latter begins to decompose measurably following crystallization of the glassy solid at about −115°; the trioxide decomposes readily between −50 and −35°. Typically, the yields of H2O3 from dissociated water vapor were of the order of 3 to 5 mol%; those of H2O4, only about one-tenth as much. Varying the distance between the microwave discharge and the cold trap was found to affect differently the yields of the various products. Those of water and peroxide showed a simple, direct correlation; the minor constituents H2O3 and H2O4 followed entirely different patterns. Only a small fraction of the peroxide is formed via the H2O4 intermediate in these systems. Less water, and more of the higher oxides, were obtained from dissociated hydrogen peroxide than from water vapor.The deuterated systems showed some unusual isotope effects. The yields of D2O3 were always higher (up to twice and even more) than those of H2O3 under similar conditions. The other products showed little or no such effect, except for occluded oxygen and ozone which decreased by about half. Finally, the deuterium polyoxides decompose at slightly higher temperatures (10 to 15°) than their hydrogen analogs. Mechanisms are proposed for the formation and decomposition of the polyoxides.

Studies on hydrogen–oxygen systems in the electrical discharge. III. Surface effects

1970 ◽  
Vol 48 (13) ◽  
pp. 2042-2046 ◽  
Author(s):  
Paul E. Brunet ◽  
Xavier Deglise ◽  
Paul A. Giguère
Keyword(s):  
Hydrogen Peroxide ◽  
Water Vapor ◽  
Power Level ◽  
Surface Effects ◽  
Surface Coatings ◽  
Pure Hydrogen ◽  
Pyrolysis Products ◽  
Electrodeless Discharge ◽  
Oxygen Gas ◽  
Hydrogen Peroxide Vapor

Surface effects in the reactions of dissociated hydrogen–oxygen systems and the products condensed therefrom have been investigated. Water vapor at about 0.1 Torr was streamed at high velocity through an electrodeless discharge confined in tubes of different materials or with various surface coatings. In all cases the products trapped in liquid nitrogen evolved oxygen gas on warming, but the relative amounts varied considerably from one type of surface to another. In some cases there was clear evidence that the walls of discharge tube were attacked by hydrogen atom bombardment. The decomposition, both thermal and electrical, of pure hydrogen peroxide vapor was studied likewise. The pyrolysis products gave off very little oxygen on warming. By contrast the products from electrical decomposition, even at low power level, evolved much oxygen, most of it above the melting point.It is concluded that there is always some decomposition of hydrogen peroxide in the trapped products. However, this does not seem sufficient to account for all the evolved oxygen; at least not in the case of dissociated water vapor.

REACTIONS IN DISSOCIATED WATER VAPOR

1951 ◽  
Vol 29 (11) ◽  
pp. 996-1009 ◽  
Author(s):  
R. A. Jones ◽  
C. A. Winkler
Keyword(s):  
Hydrogen Peroxide ◽  
Water Vapor ◽  
Room Temperature ◽  
Reaction Chamber ◽  
Glass Wool ◽  
Cold Trap ◽  
Slight Effect ◽  
Reaction Chambers ◽  
Limiting Value ◽  
Water Hydrogen

Water vapor dissociated by an electric discharge and passed into a cold trap yielded products which gave off oxygen at temperatures above −120°C. and at room temperature consisted of hydrogen peroxide and water. With products formed under given conditions, the amount of oxygen evolved with warming was proportional to the total amount of product and independent of the warming procedure. The evolution proceeded to completion at −78°C. Water was found at all trap temperatures between −78°C. and −195°C. Hydrogen peroxide was formed only if the trap temperature was below −120°C., and oxygen was evolved only from products formed below −150°C. The yields of water, hydrogen peroxide, and evolved oxygen all increased with decreasing trap temperature. As the volume of reaction chambers inserted between the discharge tube and the trap was increased, the yield of hydrogen peroxide decreased continuously, while the yield of water at first decreased and then increased to a limiting value. Packing a given reaction chamber with glass wool drastically reduced the yield of hydrogen peroxide, but had little effect on the yield of water. Packing the trap itself had only a slight effect on the yields. The results are compared with those obtained by others with the H–O2 system at low temperatures, and a mechanism is proposed to correlate the two systems.

STUDIES ON HYDROGEN–OXYGEN SYSTEMS IN THE ELECTRIC DISCHARGE: I. THE REACTIONS OF HYDROGEN ATOMS WITH HYDROGEN PEROXIDE

1966 ◽  
Vol 44 (8) ◽  
pp. 869-876 ◽  
Author(s):  
Norisuke H Ata ◽  
Paul A. Glguère
Keyword(s):  
Hydrogen Peroxide ◽  
Water Vapor ◽  
Electric Discharge ◽  
Hydrogen Gas ◽  
Reaction Products ◽  
Hydrogen Atoms ◽  
Eutectic Melting ◽  
Electrodeless Discharge ◽  
Liquid Nitrogen Trap ◽  
Unidentified Species

Hydrogen gas partly dissociated in an electrodeless discharge was mixed downstream with hydrogen peroxide vapor at low pressure (0.1 mm Hg) in a liquid nitrogen trap. The reaction products condensed readily on the wall as a clear, yellowish glass resembling that from dissociated water vapor and other related systems. A manometric study of the warming-up process has revealed four distinct steps. The first two, in which only traces of gas are given off, look like the recombination of trapped free radicals. The major evolution of oxygen upon crystallization of the glassy deposit at 160 °K is ascribed to the decomposition of hydrogen peroxide under the influence of some unidentified species generated in the electric discharge through hydrogen. Experimental evidence for this is presented. In any case the stoichiometry cannot be reconciled with the formation of a metastable intermediate, such as the hypothetical polyoxide H2O4.In the last step beginning around 215 °K more peroxide is decomposed during the eutectic melting of the solid. Qualitatively these phenomena are similar to those shown by the condensate from dissociated water vapor.

Studies on hydrogen–oxygen systems in the electrical discharge. II. The reactions of hydrogen atoms with liquid ozone

1968 ◽  
Vol 46 (16) ◽  
pp. 2649-2653 ◽  
Author(s):  
Kazimiera Herman ◽  
Paul A. Giguère
Keyword(s):  
Hydrogen Peroxide ◽  
Infrared Spectra ◽  
Electrical Discharge ◽  
Hydrogen Gas ◽  
The Other ◽  
Hydrogen Atoms ◽  
Absorption Bands ◽  
Electrodeless Discharge ◽  
Primary Products ◽  
Extreme Care

We have reinvestigated in detail the infrared spectra between 4000 and 600 cm−1 of the solid products formed by reacting liquid ozone at −190 °C with a stream of hydrogen gas dissociated in an electrodeless discharge. Extreme care was exercised to get "clean" spectra, free from any contaminants. All the spectra thus obtained showed very clearly the characteristic absorption bands of H2O2 at 2840 and 1430 cm−1, and the much weaker one at 880 cm−1; with deuterium atoms the former bands were shifted to 2100 and 1080 cm−1 respectively. Thus previous contentions that hydrogen peroxide is not one of the primary products of that reaction are disproved. The other infrared bands of H2O2 were not conspicuous, due either to their diffuse nature in the vitreous spectra or to extensive overlapping by the strong absorption of H2O, the other major component. Warming the material up to −110 °C caused some devitrification, but no significant change in the spectra. No new bands which could be assigned unambiguously to the hypothetical molecule H2O4 were observed.

Studies on Hydrogen–Oxygen Systems in the Electrical Discharge. V. Raman Spectra of the Trapped Products

1971 ◽  
Vol 49 (13) ◽  
pp. 2242-2247 ◽  
Author(s):  
Xavier Deglise ◽  
Paul A. Giguère
Keyword(s):  
Hydrogen Peroxide ◽  
Raman Spectroscopy ◽  
Water Vapor ◽  
Electrical Discharge ◽  
Amorphous Matrix ◽  
Total Reflection ◽  
Laser Raman Spectroscopy ◽  
Laser Raman ◽  
New Type ◽  
Hydrogen Polyoxides

The condensed products (at – 180 °C) of electrically dissociated water vapor and other related systems were examined by means of laser Raman spectroscopy. A new type of total reflection cell had to be developed for the study of metastable species trapped in an amorphous matrix. Besides the characteristic O—O stretching band of hydrogen peroxide at 878 cm−1, always the strongest, another fairly strong band at 500 cm−1, and a third one at about 760 cm−1 were present in all cases. A couple of weaker bands around 820–830 cm−1 and 430–440 cm−1 occurred only in oxygen-rich system (H2O2 vapor or H2O–O2 mixtures). In the latter, the presence of condensed ozone was confirmed by a band at 1025 cm−1, and occasionally another faint one around 1120 cm−1.The relative intensities of the bands varied locally in a given sample, indicating uneven composition.Isotopic shifts with 18O confirmed that these Raman bands arise from vibrations of oxygen atoms. Essentially the same results were obtained in hydrogen as in deuterium systems, except that in the latter case the new bands were appreciably stronger and sharper. The present results support the assignment of previous infrared spectra to hydrogen polyoxides, H2O3 and H2O4.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

A Head-to-Head Comparison of Hydrogen Peroxide Vapor and Aerosol Room Decontamination Systems

2011 ◽  
Vol 32 (9) ◽  
pp. 831-836 ◽  
Author(s):  
T. Holmdahl ◽  
P. Lanbeck ◽  
M. Wullt ◽  
M. H. Walder
Keyword(s):  
Hydrogen Peroxide ◽  
Cycle Time ◽  
New Technologies ◽  
Biological Indicators ◽  
The Other ◽  
Test Room ◽  
Cycle Times ◽  
Hydrogen Peroxide Vapor ◽  
In Vitro Comparison

Objective.New technologies have emerged in recent years for the disinfection of hospital rooms and equipment that may not be disinfected adequately using conventional methods. There are several hydrogen peroxide–based area decontamination technologies on the market, but no head-to-head studies have been performed.Design.We conducted a head-to-head in vitro comparison of a hydrogen peroxide vapor (HPV) system (Bioquell) and an aerosolized hydrogen peroxide (aHP) system (Sterinis).Setting.The tests were conducted in a purpose-built 136-m3test room.Methods.One HPV generator and 2 aHP machines were used, following recommendations of the manufacturers. Three repeated tests were performed for each system. The microbiological efficacy of the 2 systems was tested using 6-log Tyvek-pouchedGeobacillus stearo-thermophilusbiological indicators (BIs). The indicators were placed at 20 locations in the first test and 14 locations in the subsequent 2 tests for each system.Results.All BIs were inactivated for the 3 HPV tests, compared with only 10% in the first aHP test and 79% in the other 2 aHP tests. The peak hydrogen peroxide concentration was 338 ppm for HPV and 160 ppm for aHP. The total cycle time (including aeration) was 3 and 3.5 hours for the 3 HPV tests and the 3 aHP tests, respectively. Monitoring around the perimeter of the enclosure with a handheld sensor during tests of both systems did not identify leakage.Conclusion.One HPV generator was more effective than 2 aHP machines for the inactivation ofG. stearothermophilusBIs, and cycle times were faster for the HPV system.

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