Nanoporouscopper (CuNPore) catalysts with tunable nanoporosity were fabricated from Cu30Mn70 alloy by controlling the de-alloying temperature under free corrosion conditions. The tunable nanoporosity of CuNPore led to a significant enhancement of catalytic activity in clickchemistrywithout using any supports and bases. Characterization of CuNPore surface, high reusability, leaching experiment, and