Ag/YMn2O5 heterointerfaces mitigate water poisoning via interfacial polarization for humid ozone decomposition

Humidity-induced deactivation severely limits room-temperature catalytic ozone decomposition by blocking active sites and retarding oxygen-intermediate turnover. Herein, an Ag/YMO (Ag/YMn 2 O 5 ) heterointerface catalyst is constructed for robust ozone decomposition under humid conditions, achieving near-complete O 3 conversion at 25 °C and 90% relative humidity (RH) under a weight hourly space velocity (WHSV) of 1,200,000 mL g −1  h −1 with stable operation. A confined-space filter test further verifies the device-level applicability of Ag/YMO for rapid ozone removal. Structural analyses confirm Ag particles anchored on YMO with partially oxidized Ag species at the particle surface. X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and ultraviolet photoelectron spectroscopy (UPS) reveal electron transfer from Ag-containing domains to adjacent Mn sites, producing an electron-rich Mn interface and a polarized surface. This interfacial polarization and the resulting local electric field repel highly polar H 2 O molecules through Coulombic interactions, thereby suppressing their adsorption on Mn-related interfacial active sites. Helium temperature-programmed desorption-mass spectrometry (He-TPD-MS), water contact-angle measurements, and in situ diffuse reflectance infrared Fourier-transform spectroscopy ( in situ DRIFTS) show that this interface weakens H 2 O retention on Mn-related sites and accelerates peroxide-intermediate conversion. This work highlights electron-rich metal–oxide heterointerfaces as an effective route to humidity-tolerant ozone decomposition catalysts.