LAUSR

With NO x persisting as a problematic pollutant, understanding the interactions and reactivity of NO x species at atmospherically relevant pressures with surfaces remains essential. Synchrotron-based ambient pressure x-ray photoelectron spectroscopy (APXPS) and near-edge x-ray absorption spectroscopy fine structure (NEXAFS) were used to investigate the interactions of NO2 with a Cu2O(111) surface. The NEXAFS data reveals a pressure dependence of the oxidation of the Cu2O surface to CuO by NO2. APXPS results show NO2 chemi- and physisorption on the Cu2O surface and decomposition to NO and O, or to N and O, with the amount of the species also being pressure dependent. The combination of the two spectroscopic techniques shows a comprehensive picture of NO2 adsorption with implications for catalysis, gas sensing, and gas filtration materials.