Precursor-Based Syntheses of Mo(C,N,O)x, Molybdenum Carbide, Nitride, and Oxide Applying a Microjet Reactor

Abstract

Composite materials such as molybdenum carbides, nitrides, oxides, and mixed anionic compounds like Mo(C,N,O)x embedded in carbonaceous matrix exhibit promising potential as anode materials for lithium batteries, with a preference for fine-grained morphologies. In this study, we present a novel synthetic approach involving an inorganic–organic hybrid precursor precipitated from aqueous solutions of ammonium heptamolybdate and one of two organic species: 1,8-diaminonaphthalene (1,8-DAN) or hexamethylenediamine (HMD). The precipitation reaction can be carried out in a beaker and in a continuous process using a microjet reactor. This enables the synthesis of precursor material on the gram scale within minutes. The pyrolysis of these precursors yields mixtures of Mo(C,N,O)x, MoO2, Mo2C, Mo2N, and Mo, with the choice of organic compound significantly influencing the resulting phases and the excess carbon content in the pyrolyzed product. Notably, the pyrolysis process maintains the size and morphology of the micro- to nanometer-sized starting materials.