scispace - formally typeset

Chemical decomposition

About: Chemical decomposition is a(n) research topic. Over the lifetime, 5210 publication(s) have been published within this topic receiving 127503 citation(s). The topic is also known as: analysis reaction & chemical decomposition reaction.
More filters

Journal ArticleDOI
Abstract: Li/graphite and Li/petroleum coke cells using a in a 50:50 mixture of propylene carbonate (PC) and ethylene carbonate (EC) electrolyte exhibit irreversible reactions only on the first discharge. These irreversible reactions are associated with electrolyte decomposition and cause the formation of a passivating film or solid electrolyte interphase on the surface of the carbon. The amount of electrolyte decomposition is proportional to the specific surface area of the carbon electrode. When all the available surface area is coated with the film of decomposition products, further decomposition reactions stop. In subsequent cycles, these cells exhibit excellent reversibility and can be cycled without capacity loss.

1,133 citations

Journal ArticleDOI
TL;DR: The derived reaction kinetics allows one to qualitatively interpret the variation of the lifetime of O/sub 3/ found in model solutions and even in natural waters and during drinking water treatment.
Abstract: The decomposition of aqueous ozone is generally due to a chain reaction involving .OH radicals. Many organic solutes (impurities) can react with .OH to yield .O/sub 2//sup -/ upon addition of O/sub 2/. .O/sub 2//sup -/ transfers its electron to a further ozone molecule in a rather selective reaction. The ozonide anion (.O/sub 3//sup -/) formed immediately decomposes into a further .OH radical. Compounds that convert .OH radicals into ozone-selective .O/sub 2//sup -/, therefore, act as promoters of the chain reaction. The efficiencies of different .OH to .O/sub 2//sup -/ converters (e.g., formic acid, primary and secondary alcohols (including sugars), glyoxylic acid, and humic acids) are tested in the presence of other .OH radical scavengers that do not primarily produce .O/sub 2//sup -/ (carbonate, aliphatic alkyl compounds, and tert-butyl alcohol). The derived reaction kinetics allows one to qualitatively interpret the variation of the lifetime of O/sub 3/ found in model solutions and even in natural waters and during drinking water treatment.

1,050 citations

Journal ArticleDOI
29 Jun 2004-Biomacromolecules
Abstract: When used as fillers in polymer composites, the thermostability of cellulose crystals is important. Sulfate groups, introduced during hydrolysis with sulfuric acid, are suspected to diminish the thermostability. To elucidate the relationship between the hydrolysis conditions, the number of sulfate groups introduced, and the thermal degradation behavior of cellulose crystals, bacterial cellulose was hydrolyzed with sulfuric acid under different hydrolysis conditions. The number of sulfate groups in the crystals was determined by potentiometric titration. The thermal degradation behavior was investigated by thermogravimetric analysis. The sulfate group content increased with acid concentration, acid-to-cellulose ratio, and hydrolysis time. Even at low levels, the sulfate groups caused a significant decrease in degradation temperatures and an increase in char fraction confirming that the sulfate groups act as flame retardants. Profile analysis of the derivative thermogravimetric curves indicated thermal separation of the degradation reactions by the sulfate groups into low- and high-temperature processes. The Broido method was used to determine activation energies for the degradation processes. The activation energies were lower at larger amounts of sulfate groups suggesting a catalytic effect on the degradation reactions. For high thermostability in the crystals, low acid concentrations, small acid-to-cellulose ratios, and short hydrolysis times should be used.

925 citations

Journal ArticleDOI
Abstract: This research describes the heterogeneous catalytic reactions of H2O2 with granular size goethite (α-FeOOH) particles in aqueous solution under various experimental conditions. This is an important reaction for the environment since both H2O2 and iron oxides are common constituents of natural and atmospheric waters. Furthermore, iron oxides function as catalysts in chemical oxidation processes used for treatment of contaminated waters with H2O2. The results of this study demonstrated that the decomposition rate of H2O2 over goethite surface can be described by the second-order kinetic expression −d[H2O2]/dt = k[FeOOH][H2O2], where k = 0.031 M-1 s-1, at pH 7 in the absence of any inorganic or organic chemical species. The apparent reaction rate was dominated by the intrinsic reaction rates on the oxide surfaces rather than the mass transfer rate of H2O2 to the surface. The activation energy of the reaction of H2O2 with the iron oxide surface was determined to be 32.8 kJ/M. The reaction mechanism for the de...

800 citations

Journal ArticleDOI
30 Aug 1991-Catalysis Today
Abstract: The exhaust gas from vehicle engines and industrial boilers contains considerable amount of harmful nitrogen monoxide (NO) which causes air pollution and acid rain To remove NO, at present, catalytic reduction processes using NH3 or CO have been applied, but several problems remain to be solved It is widely accepted that catalytic decomposition is the best method for the removal of NO; however, the catalyst with consistently high activity for the reaction has never been found In this paper the present position of decomposition catalysts is mentioned and the catalytic performance of copper ion-exchanged zeolites and Ag-Co3O4 oxides etc is summarized based on the respective authors' results A reaction mechanism of the decomposition is also proposed on the Cu-zeolites In the last section the catalytic reduction of NO by hydrocarbons in the presence of oxygen, the newly developed catalytic process for removal of NO, has been introduced The observations reported here suggest that the catalytic decomposition and/or reduction may be used in practice instead of the present reduction processes

733 citations

Network Information
Related Topics (5)
Reaction mechanism

26.2K papers, 668.5K citations

94% related

15.4K papers, 280.8K citations

93% related

54.2K papers, 728.9K citations

93% related
Aqueous solution

189.5K papers, 3.4M citations

93% related

5.7K papers, 106.3K citations

92% related
No. of papers in the topic in previous years

Top Attributes

Show by:

Topic's top 5 most impactful authors

Jirong Song

7 papers, 77 citations

Fernando J. Beltrán

7 papers, 371 citations

Jian-Hua Yi

6 papers, 109 citations

Maija M. Kuklja

5 papers, 164 citations

Abd El-Aziz A. Said

5 papers, 26 citations