INVESTIGADORES
BOIX Alicia Viviana
artículos
Título:
FTIR studies of butane, toluene and nitric oxide adsorptionon Ag exchanged NaMordenite
Autor/es:
SOLEDAD G. ASPROMONTE; EDUARDO E. MIRO; ALICIA V. BOIX
Revista:
ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012 vol. 18 p. 1 - 12
ISSN:
0929-5607
Resumen:
In this work, we studied the adsorption of butane,
toluene and nitric oxide on NaMordenite exchanged with
different amounts of silver. The reactions that occurred when
the adsorbed hydrocarbons interacted with NO and the effect
of water adsorption were also addressed. Different silver
species were formed after ion exchange and they were
detected by TPR analysis. Highly dispersed Ag2O particles
were reduced at temperatures lower than 300 °C whereas
Ag+ exchanged ions showed two TPR peaks, which can
be ascribed to species exchanged at different mordenite
sites. The TPD experiments after adsorption of NO at 25 °C
showed that the only desorbed species was NO2 which was
formed by the total reduction of Ag2O particles. When the
adsorbed butane was exposed to NO (1000 ppm), isocyanate
species were formed on Ag+ ionic sites as well as Ag+?
(NOx)?CO species. Toluene adsorption was stronger than
butane since adsorbed toluene molecules were held even at
400 °C. The characteristic bands of the aromatic ring C=C
bond was observed as well as that of methyl groups interacting
with Ag+ and Na+ ions. However, the appearance of carboxylic
groups at temperatures above 300 °C in inert flow indicated
the partial oxidation of toluene due to Ag2O species
present in the samples. After contacting adsorbed toluene
with NO, different FTIR bands correspond to organic nitrocompounds,
isocyanate, cyanide and isocyanide species adsorbed
on Ag+ ions, were detected. The presence of water
inhibited the formation of NO2 species and the hydrocarbon
adsorption on Na+ sites but did not affect the toluene-Ag+
interaction..