Impact of Mineralizing Agents on Aluminum Distribution and Acidity of ZSM-5 Zeolites.

ABSTRACT: Intensive research on improving the catalytic properties of zeolites is focused on modulating their acidity and the distribution of associated Al sites. Herein, by studying a series of ZSM-5 zeolites over a broad range of Al content, we demonstrate how the nature of the mineralizing agent (F^- or OH^- ) used in hydrothermal syntheses directly impacts Al sites distribution. The proportions of Al sites, probed by ²⁷ Al NMR, depend on the Si/Al ratio for F^- , but remain identical for OH^- (from Si/Al=30 to 760). This leads to contrasting variations in weak and strong acidities. Such opposite effect of mineralizers is explained by the spatial location of negative charges and the resulting balance between short- and long-range electrostatic in

SUBMITTER: Al-Nahari S 

PROVIDER: S-EPMC10108163 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature