Triggering Low-Temperature Chlorine Activation via Interfacial Ru–O–Mn Coordination Bridges for Robust Waste Incineration Flue Gas Mercury Oxidation

Municipal solid waste incineration (MSWI) is an important anthropogenic source of elemental mercury (Hg 0 ) emissions. In MSWI flue gas treatment, achieving efficient Hg 0 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 Hg 0 oxidation. The optimized catalyst achieves over 99% conversion of Hg 0 to Hg 2+ at 150 °C. Combined experimental characterization with density functional theory (DFT) calculations demonstrates that Ru incorporation markedly enhances O 2 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 ClO x intermediates, which facilitate HgCl 2 formation and significantly improve Hg 0 oxidation efficiency. This work provides fundamental insights into low-temperature HCl activation and offers a promising strategy for mercury abatement in incineration flue gas.