Exploiting in situ NMR spectroscopy to understand non-traditional methods for zeolite synthesis

Abstract

Zeolite-formation mechanisms have long been the subject of intensive study, with most work concentrating on hydrothermal mechanisms. However, non-traditional zeolite syntheses that do not rely on hydrothermal crystallisation have provided a number of new routes to interesting and unexpected new materials, but their formation mechanisms remain poorly understood. Here, we show how simultaneous in situ liquid- and solid-state ²⁹Si NMR spectroscopy can reveal the mechanism of the formation of a zeolite from a layered silicate precursor. The study provides evidence for the species that are intercalated into the layered material and establishes those that are involved in building the inter-layer, zeolitic connections as a function of time during the zeolite formation process.