Electrocatalytic properties and physicochemical identity of Cu-intercalated ▫$WO_3$▫ nanowires

A hybrid catalyst made of copper nanocenters embedded in tungsten oxide (WO₃) nanowires shows strong electrocatalytic activity for reducing nitrates and nitrites in acidic conditions. Characterization confirmed that copper active sites are successfully incorporated into the WO₃ structure. The Cu–WO₃ system efficiently converts nitrates into ammonia—without forming hydrazine—and maintains good tolerance to competing hydrogen evolution, achieving high ammonia production rates. Additionally, the catalyst demonstrates strong performance in reducing other typically inert molecules such as oxygen, carbon dioxide, and bromates.