ISSN:
1572-879X
Schlagwort(e):
acidic sites
;
alumina
;
reaction CF2Cl2/H2
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
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.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00813224
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