Synthesis of bulk and alumina-supported γ-Mo2N catalysts by a single-step complex decomposition method

A single-step complex decomposition method for the synthesis of bulk and alumina-supported γ-Mo2N catalysts is described. The complex precursor (HMT)2(NH4)4Mo7O24·2H2O (HMT: hexamethylenetetramine) is converted to γ-Mo2N under a flow of Ar in a temperature range of 823–1023 K. Furthermore, decomposition of the precursor in a NH3 flow forms γ-Mo2N in a temperature range of 723–923 K. Compared with direct decomposition of the precursor in Ar, the reaction in NH3 shows obvious advantages that the nitride forms at a lower temperature. In addition, alumina-supported γ-Mo2N catalysts with different nitride loadings can be prepared from the alumina-supported complex precursor in the Ar or NH3 flow. The resultant catalysts exhibit good dibenzothiophene HDS activities, which are similar to the γ-Mo2N/γ-Al2O3 prepared by traditional TPR method. The catalyst prepared by decomposition in an Ar flow exhibits highest activity. It proves that such a single-step complex decomposition method possesses the potential to be a general route for the preparation of molybdenum nitride catalysts.