Search

The small size of micropores (typically <1 nm) in zeolites causes slow diffusion of reactant and product molecules in and out of the pores and negatively impacts the product selectivity of zeolite based catalysts, for example, fluid catalytic cracking (FCC) catalysts. Size-tailored mesoporosity was introduced into commercial zeolite Y crystals by a simple surfactant-templating post-synthetic mesostructuring process. The resulting mesoporous zeolite Y showed significantly improved product selectivity in both laboratory testing and refinery trials. Advanced characterization techniques such as electron tomography, three-dimensional rotation electron diffraction, and high resolution gas adsorption coupled with hysteresis scanning and density functional theory, unambiguously revealed the intracystalline nature and connectivity of the introduced mesopores. They can be considered as molecular highways that help reactant and product molecules diffuse quickly to and away from the catalytically active sites within the zeolite crystals and, thus, shift the selectivity to favor the production of more of the valuable liquid fuels at reduced yields of coke and unconverted feed. [ABSTRACT FROM AUTHOR]

The Zeolite Peacemakers The cover picture shows that a new family of materials, namely mesostructured zeolites, can bridge the gap between conventional (microporous) zeolites and surfactant‐templated (mesoporous) solids. In their Full Paper on p. 3110 ff., J. Garcia‐Martinez, X. Zou, M. Thommes and co‐workers describe how size‐tailored mesoporosity could be introduced into commercial zeolite Y crystals by a simple surfactant‐templating post‐synthetic mesostructuring process. The resulting mesoporous zeolite Y showed significantly improved product selectivity in both laboratory testing and refinery trials. A collaboration of three teams was able to characterize these materials with advanced techniques. [ABSTRACT FROM AUTHOR]

Review: 137 refs. [ABSTRACT FROM AUTHOR]