Autores UPV
Christiaan H. L. Tempelman,
Portilla Ovejero Mª Teresa,
Martinez Armero Marta Evelia,
Mezari Brahim ,
Niek G.R. de Caluwé,
Martínez Sánchez Mª Cristina,
Emiel J. M. Hensen
Abstract
Nano-crystalline MCM-22 zeolite was synthesized in a one-pot procedure by the use of an organosilane
(dimethyl-octadecyl-(3-trimethoxysilylpropyl)-ammonium chloride, TPOAC) in the zeolite synthesis gel.
This crystal growth inhibition procedure introduced mesopores in the MCM-22 crystallites. The lower
mechanical stability of the nano-crystalline MCM-22 zeolite compared with bulk MCM-22 can be
countered to some extent by pillaring. The increased external surface of the microporous zeolite domains
resulted in increased accessibility of the Brønsted acid sites, as followed from the better performance in
liquid-phase benzene alkylation with propylene as compared with bulk MCM-22. The increased accessibility
of the internal acid sites in Mo-loaded hierarchical MCM-22 was also evident from the improved
benzene selectivity during methane aromatization. Silylation of hierarchical Mo/MCM-22 was detrimental
for the catalytic performance in MDA. The nano-crystalline MCM-22 has physico-chemical and
catalytic properties intermediate between those of MCM-22 and ITQ-2 with the benefit over ITQ-2 that it
can be synthesized in a single step.
