A new study on the reactivity under various atmospheres of nanoscaled metal borides produced from molten salt synthesis is published in Inorganic Chemistry. We have gathered a multidisciplinary consortium, combining advanced nanomaterials synthesis, in situ electron microscopy and synchrotron-based in situ X-ray spectroscopies, to unravel the strong structural reorganization of these nanomaterials. DOI: 10.1021/acs.inorgchem.7b01279