Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Catalysis letters 49 (1997), S. 199-205 
    ISSN: 1572-879X
    Keywords: decomposition ; hydrolysis ; heterogeneous catalysis ; dichlorodifluoromethane ; CFC-12 ; zirconia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The hydrolytic decomposition of dichlorodifluoromethane (CFC-12) on various modified zirconium oxide surfaces has been studied. The reaction was carried out under flow conditions at 500°C. Complete CFC-12 conversion and long-time stability of the catalysts were achieved accompanied by a limitation of the undesired CFC-13 formation. A maximum CFC-12 conversion was observed on catalysts of sulfated zirconia or zirconia obtained from temperature-controlled calcination of zirconium oxide hydrate. The reaction depends on the presence or in situ formation of Brønsted acid sites. FTIR-photoacoustic measurements were performed on pyridine complexes chemisorbed on the catalyst surface in order to analyze the changes in the catalyst's acidity. The effects of the temperature and water in the reaction gas on the catalyzed decomposition of CFC-12 are examined.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 614 (1992), S. 60-64 
    ISSN: 0044-2313
    Keywords: Magnesium hydrogensulfate ; hydration ; dehydration ; thermal analysis ; X-ray analysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Hydration and Dehydration Behaviour of Magnesium HydrogensulfateMg(HSO4)2 · H2O has been prepared by crystallization from diluted sulfuric acid. The thermal destruction leads to the formation of siccative Mg(HSO4)2. This process is reversible, i. e., Mg(HSO4)2 rehydrates during cooling under formation of Mg(HSO4)2. H2O. Due to further water reception Mg(HSO4)2 · H2O decomposes at a temperature of 50°C forming Kieserite (MgSO4 · H2), MgSO4 · 1,25H2O, sulfuric acid, and water. During gentle warming of this heterogenous phase mixture it reacts under reconstruction of Mg(HSO4)2 · H2O. The thermal measurements have been carried out in dynamic as well as in static gas atmosphere.The strong dependence of the decomposition temperatures from the partial pressure of the gaseous products could be demonstrated by in situ X-ray measurements.
    Notes: Mg(HSO4)2 · H2O wird erhalten durch Kristallisation aus 70%iger Schwefelsäure. Der thermische Abbau führt direkt zur Bildung von siccativem Mg(HSO4)2. Der Vorgang ist reversibel, d. h., Mg(HSO4)2 hydratisiert beim Abkühlen wieder unter Bildung von Mg(HSO4)2 · H2O. Bei weiterer Wasseraufnahme zersetzt sich das Magnesiumhydrogensulfat-Monohydrat beginnend ab 50°C zu einer Mischung bestehend aus MgSO4 ·; H2O (Kieserit), MgSO4 ·; 1,25 H2O und Schwefelsäure/Wasser. Auch dieser Vorgang ist reversibel. Bei langsamem Aufheizen dieses Mehrphasensystems bildet sich aus der infolge Wasseraustrages aufkonzentrierten Schwefelsäure erneut das hierin beständigere Mg(HSO4)2 ·; H2O zurück.Die thermischen Messungen sind sowohl unter dynamischer wie auch statischer Gasatmosphäre durchgeführt worden.Die starke Abhängigkeit der Zersetzungstemperaturen vom Partialdruck der gasförmigen Reaktionsprodukte konnte durch röntgenographische in situ Messungen gezeigt werden.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 1266-1269 
    ISSN: 0044-2313
    Keywords: Lithium hydrogen sulfate dihydrogen sulfate ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Lithium Hydrogen Sulfate, Li2(HSO4)2(H2SO4) - Synthesis and Crystal StructureThe title compound crystallizes in good shaped single crystals from the system lithium sulfate/sulfuric acid in the orthorhombic space group Pccn, unit cell parameters a = 17.645(4), b = 5.378(1), c = 10.667(3) Å. V = 1 012.2 Å3, Z = 4, Dx = 2.009 g cm-3.There are two types of SO4 tetrahedra, SO3(OH) and SO2(OH)2, connected via hydrogen bonds forming layers parallel to the xy-plane. The layers are linked by Li atoms, which are tetrahedral coordinated by O atoms coming two by two from neighboured layers.
    Notes: Die Titelverbindung kristallisiert aus dem System Lithiumsulfat/Schwefelsäure in Form gut ausgebildeter Einkristalle in der orthorhombischen Raumgruppe Pccn, Gitterkonstanten a = 17,645(4), b = 5,378(1), c = 10,667(3) Å, V = 1 012,2 Å3, Z = 4, Dx = 2,009 g cm-3.Es liegen zwei Sorten von SO4-Tetraedern, SO3(OH) und SO2(OH)2, vor, die mittels Wasserstoffbrücken zu Schichten parallel der xy-Ebene verknüpft sind. Die Schichten werden über Li-Atome miteinander verbunden. Lithium wird dabei von jeweils zwei Sauerstoffatomen benachbarter Schichten tetraedrisch koordiniert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...