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

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 BTX is therefore critical for advancing the circular economy and achieving carbon neutrality. Here, we present a single‐step, hydrogen‐free, noble‐metal‐free catalytic process that converts waste PE into BTX with yields nearing 59%, using an unreduced Ni‐ZSM‐5 catalyst, outperforming previously reported noble‐metal or Ni‐based zeolite catalysts. The conversion of PE and long‐chain model compounds over Ni‐ZSM‐5 indicates a β‐scission pathway, as evidenced by the prominent formation of isobutene—an established β‐scission indicator. Upon Ni addition, the apparent activation energy for β‐scission decreases significantly, suggesting that Ni‐induced Lewis acidity promotes carbenium ion formation via hydride abstraction, the key step initiating β‐scission. This accelerates PE breakdown into smaller intermediates, which easily diffuse into ZSM‐5 micropores for further aromatization.