Related Experiment Video
Updated: Jun 28, 2026

Organic Structure-directing Agent-free Synthesis for *BEA-type Zeolite Membrane
Published on: February 22, 2020
Production of aromatics from high density polyethylene over a hierarchical zeolite synthesised from steam-assisted
Xinrui Zheng1, Meng He2, Longfei Lin3,4
1Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China.
Abstract:
The conversion of high-density polyethylene wastes to aromatic feedstocks in noble-metal-free systems poses a significant challenge. Here, we report a steam-assisted synthesised zeolite (SA-HZSM-5) that can promote the conversion of high-density polyethylene to aromatics, achieving simultaneously high conversion and selectivity (85.4% and 49.2%, respectively) at 260 °C, outperforming noble metal-based catalysts, such as Ru-HZSM-5, under the same conditions. The produced aromatics predominantly consist of valuable monocyclic aromatics (circa 85%). The steam-assisted synthetic method endows a specific distribution of Lewis and Brønsted acid sites in SA-HZSM-5. In situ neutron diffraction and infrared spectroscopy, coupled with modelling, reveal a dual-site adsorption mechanism of mono-olefins intermediates, facilitating their transformation into dienes with suitable spaced double bonds, a feature that is crucial for the sequential cyclisation and dehydroaromatisation into aromatic compounds. This study underscores the potential of hierarchical zeolite materials for efficient upcycling of plastic wastes into chemical feedstocks.
Related Concept Videos
Ziegler–Natta Chain-Growth Polymerization: Overview
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Free-Radical Chain Reaction and Polymerization of Alkenes
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Aromatic Compounds: Overview
In 1825, Faraday isolated benzene...

