Ni-Hß-zeolite catalysts prepared by deposition-precipitation
Por:
Nares R., Ramírez J., Gutiérrez-Alejandre A., Louis C., Klimova T.
Publicada:
1 ene 2002
Resumen:
The deposition-precipitation (DP) method, which was extensively developed for the preparation of Ni/SiO2, is applied here to the preparation of Ni/Hß zeolite catalysts. The Ni/Hß samples prepared at different deposition-precipitation times (1-4 h) were characterized by BET, XRD, TPR, FTIR, SEM, and TEM. The results indicate that as in the case of the deposition-precipitation of Ni on silica of low surface area, for short DP times (=2 h), nickel hydroxide is the main Ni(II) phase deposited on Hß zeolite whereas, for longer DP times (3 and 4 h), the Ni(II) phase is a mixture of nickel hydroxide and 1:1 nickel phyllosilicate. The behavior of the OH groups of the Hß zeolite indicates that the Ni(II) phase species are formed mainly on the external surface of the zeolite. After reduction at 450°C, the samples contain well-dispersed Ni metal particles with sizes between 9.5 and 120 Å and with average particle sizes between 29 and 44 Å, depending on the DP time.
Filiaciones:
Nares R.:
Departamento de Ingenieria Quimica, Facultad de Quimica, UNAM, Cd. Universitaria, Mexico D.F., (04510), Mexico
Laboratoire de Reactivite de Surface, URA1106 CNRS, Universite P. et M. Curie, Place Jussieu, 75252 Paris Cedex 05, France
Ramírez J.:
Departamento de Ingenieria Quimica, Facultad de Quimica, UNAM, Cd. Universitaria, Mexico D.F., (04510), Mexico
Gutiérrez-Alejandre A.:
Departamento de Ingenieria Quimica, Facultad de Quimica, UNAM, Cd. Universitaria, Mexico D.F., (04510), Mexico
Louis C.:
Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas, 152, Mexico, D. F., (07730), Mexico
Klimova T.:
Departamento de Ingenieria Quimica, Facultad de Quimica, UNAM, Cd. Universitaria, Mexico D.F., (04510), Mexico
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