Atomic-Insight into Zeolite Catalyst Forming—an Advanced NMR Study
Résumé
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 hasn't received the attention it deserves from academia. Herein, we present atomic-level insight in the solid-state chemistry taking place during the extrusion process by advanced NMR spectroscopy techniques (Indirect 27 Al{ 1 H}DNP MAS and 27 Al-{ 29 Si} J-HMQC). In particular, we: i) elucidate the chemical reactions taking place between atype Y FAU zeolite (Si/Al = 2.3) and abinder (pseudoboehmite), producing new active sites different than those present in either the zeolite or binder, ii) determine the location of these new active sites by a combination of DNP build-up time (TDNP)extracted from { 1 H}-27 Al saturation-recovery CP experiments and 2D heteronuclear 29 Si-27 Al 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.
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