Triggering Low-Temperature Chlorine Activation via Interfacial Ru-O-Mn Coordination Bridges for Robust Waste...

Municipal solid waste incineration (MSWI) is an important anthropogenic source of elemental mercury (Hg0) emissions. In MSWI flue gas treatment, achieving efficient Hg0 oxidation relies on the active participation of HCl under typical downstream operating conditions (<200 °C). However, the activation of HCl remains a formidable challenge at low temperatures. Herein, we rationally design a perovskite oxide catalyst featuring Ru-O-Mn coordinated active sites to promote HCl activation via a low-temperature Deacon-like pathway, enabling efficient in situ Cl* generation for Hg0 oxidation. The optimized catalyst achieves over 99% conversion of Hg0 to Hg2+ at 150 °C. Combined experimental characterization with density functional theory (DFT) calculations demonstrates that Ru incorporation markedly enhances O2 dissociation at the Ru-O-Mn interfacial sites and substantially lowers the energy barrier for HCl dehydrogenation by 0.52 eV, thereby promoting Cl* formation. The generated Cl* species further interact with surface oxygen (O*) to form highly reactive ClOx intermediates, which facilitate HgCl2 formation and significantly improve Hg0 oxidation efficiency. This work provides fundamental insights into low-temperature HCl activation and offers a promising strategy for mercury abatement in incineration flue gas.