Unlocking the Potential of Hidden Sites in Faujasite: New Insights in a Proton Transfer Mechanism

Abstract

Zeolite Yand its ultra-stabilized hierarchicald erivative (USY) are the most widely used zeolite-based heterogeneous catalysts in oil refining,p etrochemisty,a nd other chemicals manufacturing.A fter almost 60 years of academic and industrial research, their resilience is unique as no other catalyst displaced them from key processes such as FCC and hydrocracking.The present study highlights the key difference leading to the exceptional catalytic performance of USY versus the parent zeolite Yi namulti-technique study combining advanced spectroscopies (IR and solid-state NMR) and molecular modeling.The results highlight ahitherto unreported proton transfer involving inaccessible active sites in sodalite cages that contributes to the exceptional catalytic performance of USY.

The Influence of Inserted Metal Ions on Acid Strength of OH Groups in Faujasite

“…Special attention is dedicated to the understanding of the location, number, type, and accessibility of acid sites in zeolite structures [9], which are needed to fine-tune the catalytic properties of zeolites. The acid strength of OH groups can be measured using various probe molecules such as carbon monoxide [10], pyridine, or deuterated acetonitrile at low-pressure conditions.…”

Opening sodalite cages of X zeolite for boosting toluene side-chain alkylation performance

“…28 Herein, we attribute the enhanced side-chain alkylation activities to spatial confinement within the smaller SOD cages than in the supercages of zeolite X after 15 min NH 4 F etching. 29 In conclusion, the structural opening of the sodalite cages in X zeolites is achieved by a fast, easily controllable fluoride etching at moderate conditions, thereby increasing its micropore volume (ca. 24% increment).…”

In situhierarchical pore engineering in small pore zeoliteviamethanol-mediated NH4F etching

“…6 These limitations signicantly restrict the achievable catalytic performance of zeolites. 7 To improve the effectiveness of zeolites in industrial reactions, hierarchical zeolites with tailored mesoporosities integrated with intrinsic microporosities have been synthesized using various strategies over the past few decades. 8,9 These strategies can be broadly categorized into post-treatment and template synthesis routes.…”