Maxence Valla

TL;DR: This approach unambiguously shows the presence of framework Sn(IV)-active sites in an octahedral environment, which probably correspond to so-called open and closed sites, respectively (namely, tin bound to three or four siloxy groups of the zeolite framework).

TL;DR: Dynamic nuclear polarization surface enhanced NMR spectroscopy and density functional theory calculations show that on silica and alumina surfaces, molecular aluminum and silicon precursors are preferentially grafted on sites that enable the formation of Al(IV) and Si( IV) interfacial sites.

TL;DR: In this article, a systematic study of the morphology and atomic-level structure of Sn-β zeolites using DNP NMR spectroscopy in combination with first-principles calculations leads to a proposal of specific structural features that are important for high activity.

TL;DR: DNP-SENS experiments can be carried on many types of uniform colloidal nanomaterials containing NMR-active nuclei, in the presence of either hydrophilic (ion-capped surfaces) or hydrophobic (capping ligands with long hydrocarbon chains) surface functionalities.

TL;DR: Results indicate that extra framework Al centers in acidic zeolites, which are associated with alumina, can play a key role in the formation of the first carbon–carbon bond, the initiation step of the industrial MTO process.