Cu₂O quantum‐dot particles prepared from nanostructured copper**

Higly disperse copper oxides are widely used as catalysts for industrial processes, for example in methanol synthesis. The supports used for these catalysts hamper their characterization of the copper oxide species involved. Here, a procedure for the preparation of unsupported, nanostructured, and pure Cu 2 O samples is reported. The process involved the production of nanonstructured copper and the subsequent controlled oxidation of this material.