Enhancing the Conversion Efficiency of Polyethylene to Methane through Codoping of Mn Atoms into Ru Centers and CeO Supports.

Chemical conversion has emerged as an effective approach for disposing waste plastics; however, the product diversity in traditional methods leads to pressing challenges in product separation and purification. As a pioneering advancement, the comprehensive transformation of waste plastics into CH presents an attractive prospect: directly yielding high-purity products. Significantly, CH is an important hydrogen carrier and an industrial feedstock. However, there is still much room for enhancing the overall efficiency. Herein, we show a new strategy to construct a high-efficiency and robust polyethylene (PE) upgrading catalyst by codoping Mn heteroatoms into both RuO and CeO. We found that these Mn heteroatoms effectively bolster the stability of Ru species under high-temperature reduction conditions. The harmonious coexistence of Ru and Ru significantly refines the reaction pathway by enhancing the adsorption of the alkane intermediates. Consequently, we achieved an impressive PE conversion rate exceeding >99% with nearly 99% toward CH at a moderate temperature of 250 °C within 8 h. Our discovery not only opens a new window for catalyst upgrading but also presents exciting opportunities for the in-depth conversion of waste plastics into complex, high-purity fine chemicals through methane-mediated catalysis.