ISSN:
1572-879X
Schlagwort(e):
EXAFS
;
Pt/Al2O3 catalyst
;
temperature
;
pressure
;
carbon deposition
;
carbon removal
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract EXAFS has been used to follow in situ the structural evolution of a Pt/Al2O3 catalyst during removal of carbon by hydrogenation, after reduction and carbon deposition. After reduction at 350 °C, the total hydrogen pressure was raised to 3 atm. and n-heptane was injected over the sample. EXAFS measurements at the Pt edge were carried out with simultaneous on-line EXAFS analysis of the spectra. After observing the rapid formation of a carbon-platinum bond which is unmodified with time, we stopped the heptane flow, raised the temperature to 450 °C, and maintained hydrogen flow at 3 atm. The disappearance of the platinum-carbon bond during heat treatment in hydrogen was monitored via on-line analysis. No sintering of the metal particles was observed. EXAFS is thus proven to be an efficient tool to study not just structural changes of a catalyst during a hydrocarbon reaction [1], but also to use it as a technique to study other catalytic phenomena as well.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00764191
Permalink
