AI Article Synopsis
- The production of p-xylene through the methanol to aromatics (MTA) reaction faces challenges due to the trade-off between catalytic stability and selectivity, influenced by zeolite particle size and acid site density.
- In this study, researchers created hollow triple-shelled Zn/MFI single crystals using a novel ultra-dilute liquid-phase growth technique, featuring a ZSM-5 layer surrounded by two silicalite-1 layers.
- This innovative structure showed improved performance, achieving over 40 hours of methanol conversion and more than 35% selectivity for p-xylene, while also allowing for direct imaging of Zn species within the ZSM-5 layer.
Article Abstract
The production of p-xylene from the methanol to aromatics (MTA) reaction is challenging. The catalytic stability, which is inversely proportional to the particle size of the zeolite, is not always compatible with p-xylene selectivity, which is inversely proportional to the external acid sites. In this study, based on a nano-sized zeolite, we designed hollow triple-shelled Zn/MFI single crystals using the ultra-dilute liquid-phase growth technique. The obtained composites possessed one ZSM-5 layer (≈30 nm) in the middle and two silicalite-1 layers (≈20 nm) epitaxially grown on two sides of ZSM-5, which exhibited a considerably long lifetime (100 % methanol conversion >40 h) as well as an enhanced shape selectivity of p-xylene (>35 %) with a p-xylene/xylene ratio of ≈90 %. Importantly, using this sandwich-like zeolite structure, we directly imaged the Zn species in the micropores of only the ZSM-5 layer and further determined the specific structure and anchor location of the Zn species.
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| http://dx.doi.org/10.1002/anie.202114786 | DOI Listing |
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