# The Use of Metal/ZSM-5 Nanosheet for Efficient Catalytic Cracking of Cross-Linked Polyethylene for High-Voltage Cable Insulation

## TL;DR

This paper explores using metal-loaded ZSM-5 nanosheets to efficiently break down cross-linked polyethylene into valuable chemicals, with silver showing the best performance.

## Contribution

The study introduces metal-loaded ZSM-5 nanosheets as an effective catalyst for XLPE pyrolysis, with optimized metal loading for enhanced performance.

## Key findings

- Ag-loaded ZSM-5 achieved 94.1% XLPE conversion at 380°C with high light olefin and BTX yields.
- Moderate Ag loading (5 wt%) provided the best balance of conversion and selectivity.
- Metal loading tunes acidity and pore structure, enabling controlled product distribution.

## Abstract

Cross-linked polyethylene (XLPE) has been widely used in high-voltage cables due to its superior properties, but its thermoset cross-linked structure makes it difficult to recycle. Catalytic pyrolysis offers a feasible pathway for converting XLPE into high-value chemicals. In this study, a systematic study on the catalytic cracking of XLPE using metal ion-loaded ZSM-5 nanosheets was conducted, and ZSM-5 nanosheets loaded with Ag, Mo, Ni, and Ce were prepared via ion exchange. After metal loading, ZSM-5 retained the MFI framework structure, but the specific surface area and mesopore volume varied depending on the type of metal. Temperature-Programmed Desorption of Ammonia results indicated that metal–support interactions enhanced the acidity of ZSM-5. Among the catalysts, Ag-loaded ZSM-5 exhibited the highest efficiency: with 10 wt% Ag, at 380 °C, the conversion reached 94.1%, with 52.5% light olefins in the gas phase and 59.4% benzene, toluene, and xylene (BTX) in the liquid products. Further studies on different Ag loadings revealed that moderate Ag loading (5 wt%) provided the best overall balance, maintaining 92.3% conversion, 56.1% selectivity to light olefins, and 58.2% BTX in the liquid fraction. These findings demonstrate that tuning the metal loading effectively optimizes the acidity and pore structure of ZSM-5, thereby enabling controlled regulation of XLPE pyrolysis product distribution.