Preparation of nanostructured molybdenum carbides for CO hydrogenation

Abstract

Novel Mo₂C/C nano/microcomposites were prepared via a facile approach involving the hydrothermal carbonization of a solution of glucose as a carbon precursor in the presence of ammonium heptamolybdate tetrahydrate. The samples were subsequently characterized by X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric analysis, N₂-physisorption, scanning electron microscopy and high-resolution transmission electron microscopy. The effect of the carbonization agents (Ar, CH₄/H₂ = 0.2, and H₂) was investigated. In particular, the carbonization behaviours and the evolution of Mo species in the catalysts during the carbonization process and the effect on CO hydrogenation for higher alcohol synthesis were extensively studied. During the carbonization step, the catalyst structures experienced an extensive restructuring process, which in turn induced the different performances in the higher alcohol synthesis. Moreover, the nanostructured molybdenum carbides synthesized by this method exhibited great performances in CO hydrogenation for higher alcohol synthesis.