Enhancing the Conversion\nEfficiency of Polyethylene\nto Methane through Codoping of Mn Atoms into Ru Centers and CeO<sub>2</sub> Supports

Chemical conversion has emerged as an effective approach\nfor disposing\nwaste plastics; however, the product diversity in traditional methods\nleads to pressing challenges in product separation and purification.\nAs a pioneering advancement, the comprehensive transformation of waste\nplastics into CH<sub>4</sub> presents an attractive prospect: directly\nyielding high-purity products. Significantly, CH<sub>4</sub> is an\nimportant hydrogen carrier and an industrial feedstock. However, there\nis still much room for enhancing the overall efficiency. Herein, we\nshow a new strategy to construct a high-efficiency and robust polyethylene\n(PE) upgrading catalyst by codoping Mn heteroatoms into both RuO<sub>2</sub> and CeO<sub>2</sub>. We found that these Mn heteroatoms effectively\nbolster the stability of Ru<sup>δ+</sup> species under high-temperature\nreduction conditions. The harmonious coexistence of Ru<sup>0</sup> and Ru<sup>δ+</sup> significantly refines the reaction pathway\nby enhancing the adsorption of the alkane intermediates. Consequently,\nwe achieved an impressive PE conversion rate exceeding >99% with\nnearly\n99% toward CH<sub>4</sub> at a moderate temperature of 250 °C\nwithin 8 h. Our discovery not only opens a new window for catalyst\nupgrading but also presents exciting opportunities for the in-depth\nconversion of waste plastics into complex, high-purity fine chemicals\nthrough methane-mediated catalysis.