INSITU

The INSITU project aims to identify the synthesis conditions leading to nanostructured iron nitrides of controlled composition and structure. Indeed, depending on their composition and structure, these nanomaterials, deprived of any critical, costly or toxic element, may be used to develop sustainable batteries, electrocatalysts for fuel cells or H2 production, or eco-friendly magnets (of controlled anisotropy). The process involves nitriding well-defined zerovalent iron nanoparticles with ammonia (diluted in argon). The nitridation process of these zerovalent iron nanoparticles will be studied at the single particle level, both experimentally in operando by transmission electron microscopy, and theoretically. Particular attention will be paid to the synthesis intermediates (different nitride phases and gaseous species formed) and to the homogeneity of the final nanoparticles. Based on the comparison of the results, the key parameters for the synthesis of nanostructured homogeneous iron nitrides phases will be defined. The transfer of this knowledge for the production of the nanostructured materials on a macroscopic scale will then be implemented, and the properties of the nanomaterials evaluated. This project is based on a partnership between four laboratories with complementary skills : synthesis of nanomaterials (LCC-Toulouse), structural studies (MPQ-Paris), modelling (LPCNO-Toulouse) and study of magnetic properties (CEMES-Toulouse), and on initial results from a collaboration between the LCC and CEMES concerning the formation of a first nitride phase: epsilon-Fe2N.