Influence of Preparation Conditions of Mixed-valence Co/ZSM-5 Zeolites on Their Adsorption and Catalytic Properties in CO Oxidation

Autor: Ludmila P. Oleksenko, Vitaly K. Yatsimirsky, Larisa V. Lutsenko
Jazyk: angličtina
Rok vydání: 2002
Předmět:
Zdroj: Adsorption Science & Technology, Vol 20 (2002)
Druh dokumentu: article
ISSN: 0263-6174
2048-4038
DOI: 10.1260/02636170260295551
Popis: The adsorption properties, thermal stability and catalytic activity in CO oxidation of Co 2+ , Co 3+ -containing ZSM-5 zeolite systems with different metal loadings were studied. Treatment in H 2 caused an increase in the activity of Co 2+ /ZSM-5 and Co 2+ –Co 3+ /ZSM-5 systems, but the activity of the Co 3+ /ZSM-5 system remained unchanged, demonstrating the very low reducibility of the [Co(NH 3 ) 6 ] 3+ ion when embedded in the zeolite framework. The catalytic activity changed in the order: Co 3+ /ZSM-5 < Co 2+ –Co 3+ /ZSM-5 < Co 2+ /ZSM-5. A correlation was established between the temperature necessary for the total decomposition of the cobalt salts introduced into the zeolite, the acidity, the coordination state of the Co ions and the catalytic activity of the cobalt-containing zeolites.
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