One-pot preparation and characterization of bifunctional Ni-containing ZSM-5 catalysts

Authors: Gerardo Vitale, Hebert Molero, Eumir Hernandez, Samuel Aquino, Viola Birss, Pedro Pereira-Almao

Abstract:
Aconvenient method for the incorporation of nickel into an aluminosilicate MFItype zeolite, which avoids the impregnation of nickel, drying and further calcinations steps, to produce a bifunctional catalyst in a cost efficient way, is presented. The one step preparation involves the addition of the nickel source in the zeolite preparation step and anchoring it during the crystallization process. After calcination to remove the organic template, the composite zeolite is ion exchanged to produce the acid form, which already has the nickel incorporated and no further steps are required. The incorporation of high contents of nickel (up to 5 wt% nominal) induced important modifications in the produced materials. As the amount of nickel increases, the textural properties are modified and lower micropore area and volume and higher mesopore and total volumes are observed. The amount of acidic sites decreased and the sites seem to be ofthe Brønsted kind. The nickel seems to be well dispersed or anchored in the prepared material and then high temperatures are used to reduce the oxidation state of nickel in the material; however, the catalyst with 1 wt% nickel incorporated showed good physical–chemical properties and was as active as other catalysts for the hydroconversion of toluene. The tested catalyst had a good tolerance to sulfur, indicating that part of the nickel incorporated is hindered from sulfur poisoning but is active for the dissociation of hydrogen during hydrogenation in the presence of sulfur.

Keywords:
Ni-ZSM-5
Bifunctional catalysts
Hydroconversion
Toluene hydrogenation
Hydrothermal synthesis

Published in: Applied catalysis A: General  (Volume 452, Pages 1-222, 15 February 2013)

Publisher: Elsevier

ISSN Information: 0926-860X

One-pot preparation and characterization of bifunctional Ni-containing ZSM-5 catalysts

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