posted on 2021-09-07, 11:34authored byLouwanda Lakiss, Cassandre Kouvatas, Jean-Pierre Gilson, Valentin Valtchev, Svetlana Mintova, Christian Fernandez, Robert Bedard, Suheil Abdo, Jeffery Bricker
The
main goal of this study is to understand, at the atomic level,
the chemical interactions occurring between an active phase, a FAU
zeolite in this case, and its binder during catalyst forming. This
unit operation is a critical step in catalyst scale up and commercialization
but has not received the attention it deserves from academia. Herein,
we present atomic level insight into the solid-state chemistry taking
place during the extrusion process by advanced NMR spectroscopy techniques
(indirect 27Al{1H}DNP MAS and 27Al-{29Si} J-HMQC). In particular, we: (i) elucidate the chemical
reactions taking place between a type Y FAU zeolite (Si/Al = 2.3)
and a binder (pseudo-boehmite), producing new active sites different
than those present in either the zeolite or binder and (ii) determine
the location of these new active sites by a combination of DNP build-up
time (TDNP) extracted from {1H}–27Al saturation-recovery cross polarization
experiments and 2D heteronuclear 29Si–27Al NMR. This illustrates the power of advanced NMR techniques to
elucidate the nature and location of newly created active sites during
catalyst forming and provides insight into a key step to further fine-tune
industrial catalysts.