Direct Polyethylene Photoreforming into Exclusive Liquid Fuel over Charge-Asymmetrical Dual Sites under Mild Conditions
Xingchen Jiao, Zexun Hu, Kai Zheng, Juncheng Zhu, Yang Wu, Xiaojing Zhang, Jun Hu, Wensheng Yan, Junfa Zhu, Yongfu Sun, Yi Xie
Abstract
Direct polyethylene photoreforming to high-energy-density C2 fuels under mild conditions is of great significance and still faces a huge challenge, which is partly attributed to the extreme instability of *CH2CH2 adsorbed on the traditional catalysts with single catalytic sites. Herein, charge-asymmetrical dual sites are designed to boost the adsorption of *CH2CH2 for direct polyethylene photoreforming into C2 fuels under normal temperature and pressure. As a prototype, the synthetic Zr-doped CoFe2O4 quantum dots with charge-asymmetrical dual metal sites realize direct polyethylene photoreforming into acetic acid, with 100% selectivity of liquid fuel and the evolution rate of 1.10 mmol g–1 h–1, outperforming those of most previously reported photocatalysts under similar conditions. In situ X-ray photoelectron spectra, density-functional-theory calculations, and control experiments reveal the charge-asymmetrical Zr–Fe dual sites may act as the predominate catalytic sites, which can simultaneously bond with the *CH2CH2 intermediates for the following stepwise oxidation to form C2 products.