Carbon Reduction of 9%! Southwest Jiaotong University Transforms Waste PET Into High-Performance Catalysts

Recently, Researcher Wang Xin from the Institute of Frontier Science at Southwest Jiaotong University and Professor Wang Hui from Xi'an Jiaotong University published a research article titled "Upcycling of Waste PET Plastics to Fabricate Cobalt-Nickel Metal–Organic Frameworks and Their Phosphides for Efficient Oxygen Evolution Reaction" in Rare Metals. They proposed a green strategy for the high-value conversion of waste PET plastics into efficient electrocatalytic materials for the oxygen evolution reaction (OER).

This work utilizes waste PET plastic as a source of organic ligands to directly construct a bimetallic cobalt-nickel metal-organic framework Co₄Ni-MOF through a one-step hydrothermal method, which is further processed by phosphorization to obtain the highly active Co₄NiP-400 catalyst. The research results indicate that the phosphorized material exhibits excellent oxygen evolution performance under alkaline conditions, requiring only a 287 mV overpotential at a current density of 10 mA·cm⁻², with a Tafel slope as low as 51 mV·dec⁻¹, while also demonstrating good cycling stability and long-term operational stability. Further theoretical calculations reveal that the phosphorization process effectively tunes the electronic structure of the catalyst, optimizes the adsorption behavior of reaction intermediates, and alters the rate-determining step of the oxygen evolution reaction, thereby significantly reducing the reaction energy barrier. Life cycle assessment (LCA) results further indicate that, compared to the traditional terephthalic acid route, synthesizing such MOF materials using waste PET can lower greenhouse gas emissions and marine eutrophication potential, reflecting good environmental friendliness and resource recycling value. This study provides new insights for the high-value utilization of waste plastics and the design of green electrocatalytic materials.

Figure 1 Preparation route and microstructural characterization of waste PET-derived Co₄NiP-400. (A) Schematic illustration of catalyst preparation; (B, C) Co₄Ni-MOF and Co₄TEM image of NiP-400; (D) Co₄HRTEM image of NiP-400; (E) Co₄SAED pattern of NiP-400; (F) Co₄EDX elemental distribution maps of NiP-400.