Chlorine-mediated low-temperature solar-thermally catalytic PMMA degradation into liquid fuels

Converting waste polymers into liquid fuels not only mitigates serious environmental pollution but also facilitates the recycling of these valuable carbon-energy carriers. To address the high reaction temperatures, high energy consumption, and poor selectivity in polymer degradation industries, effective catalysts and photon energy utilization are essential. Compared to standard heterogeneous catalysts (zeolites, supported noble metals, transition metal oxides, etc.), FeOCl shifts the paradigm toward a low-temperature, solar-driven chemical path via high-energy oxidation. Based on a novel chain-activation and cracking strategy, this study achieves low-temperature catalytic degradation of PMMA into liquid fuels via chlorine-mediated solar-thermal catalysis, using dichlorobenzene to generate chlorine radicals (Cl˙). With layered FeOCl catalysts under mild conditions (130-150 °C) and light irradiation (utilizing photo-generated holes), PMMA was successfully converted into alkanes (C₁₄-C₂₀). Under optimized conditions, polymer degradation reached ∼ 95% (by GPC), yielding primarily liquid fuels along with chlorinated polypropylene (Cl-PP, 10% by mass) and trace amounts of gaseous products (H₂, CH₄, CO, and CO₂). This approach demonstrates broader applicability to other plastics (PVC and PE/PET blend). It effectively overcomes the limitations of conventional high-temperature processes along with superior selectivity, controllability, and clean energy input, offering a promising solution for sustainable carbon resource utilization.