Toward carbon neutrality: Single‐step polyethylene upcycling to BTX using Ni‐ZSM‐5 catalyst DOI
Wenjie Wang,

Jiaxing Zhang,

Xiaohu Ge

et al.

AIChE Journal, Journal Year: 2025, Volume and Issue: unknown

Published: May 10, 2025

Abstract Benzene, toluene, and xylene (BTX) are currently produced mainly through energy‐intensive naphtha reforming, with around half of the BTX output used for plastic production. Developing an efficient method to convert polyethylene (PE)—the most abundant plastic—into is therefore critical advancing circular economy achieving carbon neutrality. Here, we present a single‐step, hydrogen‐free, noble‐metal‐free catalytic process that converts waste PE into yields nearing 59%, using unreduced Ni‐ZSM‐5 catalyst, outperforming previously reported noble‐metal or Ni‐based zeolite catalysts. The conversion long‐chain model compounds over indicates β‐scission pathway, as evidenced by prominent formation isobutene—an established indicator. Upon Ni addition, apparent activation energy decreases significantly, suggesting Ni‐induced Lewis acidity promotes carbenium ion via hydride abstraction, key step initiating β‐scission. This accelerates breakdown smaller intermediates, which easily diffuse ZSM‐5 micropores further aromatization.

Language: Английский

Polyethylene Upcycling to Liquid Alkanes in Molten Salts under Neat and External Hydrogen Source-Free Conditions DOI
Liqi Qiu, Felipe Polo‐Garzon,

Luke L. Daemen

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 7, 2025

Development of facile approaches to convert plastic waste into liquid fuels under neat conditions is highly desired but challenging, particularly without noble metal catalysts and an external hydrogen source. Herein, efficient selective polyethylene-to-gasoline oil (branched C6-C12 alkanes) conversion was achieved mild (<170 °C) using commercially available AlCl3-containing molten salts as reaction media provide catalytic sites (no extra solvents, additives, or feeding). The high efficiency selectivity ensured by the abundant active Al with strong Lewis acidity (comparable type in acidic zeolite) ionic nature stabilize carbenium intermediates. Dynamic genesis elucidated via time-resolved K-edge soft X-ray 27Al NMR, confirming tricoordinated Al3+ its coordination as-generated alkene/aromatic formation polyethylene chain variation illustrated inelastic neutron scattering (INS) isotope-labeling experiment. Theoretical simulations further demonstrated successive hydride abstraction, β-scission, isomerization, internal transfer pathway AlCl3 sites. This system can achieve robust, densely assembled, molecular weight model compounds alkane products diesel range.

Language: Английский

Citations

0
Toward carbon neutrality: Single‐step polyethylene upcycling to BTX using Ni‐ZSM‐5 catalyst DOI
Wenjie Wang,

Jiaxing Zhang,

Xiaohu Ge

et al.

AIChE Journal, Journal Year: 2025, Volume and Issue: unknown

Published: May 10, 2025

Abstract Benzene, toluene, and xylene (BTX) are currently produced mainly through energy‐intensive naphtha reforming, with around half of the BTX output used for plastic production. Developing an efficient method to convert polyethylene (PE)—the most abundant plastic—into is therefore critical advancing circular economy achieving carbon neutrality. Here, we present a single‐step, hydrogen‐free, noble‐metal‐free catalytic process that converts waste PE into yields nearing 59%, using unreduced Ni‐ZSM‐5 catalyst, outperforming previously reported noble‐metal or Ni‐based zeolite catalysts. The conversion long‐chain model compounds over indicates β‐scission pathway, as evidenced by prominent formation isobutene—an established indicator. Upon Ni addition, apparent activation energy decreases significantly, suggesting Ni‐induced Lewis acidity promotes carbenium ion via hydride abstraction, key step initiating β‐scission. This accelerates breakdown smaller intermediates, which easily diffuse ZSM‐5 micropores further aromatization.

Language: Английский

Citations

0