Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles: DFG German National Licenses  (2)
  • acid sites  (1)
  • acidic sites  (1)
Source
  • Articles: DFG German National Licenses  (2)
Material
Years
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    31P and119Sn high resolution solid state CP/MAS NMR study of Al2O3-SnO2 systems (1994)
    Springer
    Catalysis letters 23 (1994), S. 119-126 
    Details
    ISSN: 1572-879X
    Keywords: Al2O3-SnO2 catalysts ; acid sites ; Lewis acid ; trimethylphosphine ; 13P NMR ; 119Sn NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A series of Al2O3-SnO2 catalysts with the mole ratio of Al2O3 to SnO2 equal to 1:1, 1 ∶ 0.5, 1 ∶ 0.1, 1 ∶ 0.05 and 1 ∶ 0.01 were characterized by31P NMR of adsorbed trimethyl phosphine (TMP) and119Sn MAS NMR spectroscopy. It was found from31P NMR that no Brønsted acid sites exist in these samples. Pure SnO2 shows two different types of Lewis acid sites; in the mixed oxide samples a Lewis peak characteristic of pure Al2O3 is always seen, together with either one or two other Lewis peaks, depending on the Sn concentration.119Sn CP/MAS NMR spectra of the highest Sn-content sample show one narrow line at −603 ppm superimposed on a very broad line, indicating a strong interaction between Al and Sn oxides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812139
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    31-P NMR study study of acidic sites on Al2O3 and Al2O3-SnO2 after reaction with CCl2F2/H2 (1995)
    Springer
    Catalysis letters 32 (1995), S. 305-312 
    Details
    ISSN: 1572-879X
    Keywords: acidic sites ; alumina ; reaction CF2Cl2/H2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The surface acidic properties of two series of samples,γ-Al2O3 andγ-Al2O3-SnO2 after reaction with CCl2F2/H2 (CFC12/H2), have been investigated by solid state high resolution CP/MAS 31-PNMR, using trimethylphosphine (TMP) as a probe molecule. It was found after reaction, that Brønsted acid sites were formed on theγ-Al2O3 surface. The longer the reaction time, the more rigidly TMP bonded to the acid sites. For theγ-Al2O3-SnO2 system, Brønsted acid sites were also found on both the Al2O3 and SnO2 surfaces after reaction of theγ-Al2O3-SnO2 system with CFC12/H2. The signal intensity relevant to these sites, indicates that the SnO2 component is attached to, and therefore covers Brønsted sites ofγ-Al2O3. Two types of Lewis acid site initially present on SnO2 were not observed after reaction with CFC12/H2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813224
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...