A novel route to the synthesis of bulk and well dispersed alumina-supported Ni2Mo3N catalystsvia single-step hydrogen thermal treatment

Abstract

In this study, a facile method for the synthesis of bulk and alumina-supported Ni₂Mo₃N is described. The synthesis is based on the heat treatment of a mixed-salt precursor in a H₂ flow at 873 K. The mixed-salt precursor is obtained by evaporating ammonia solution of Ni(CH₃COO)₂ and (NH₄)₆Mo₇O₂₄ with a fixed Ni/Mo molar ratio of 2 : 3. The formation process of the bimetallic molybdenum nitride has been investigated, which indicates that the labile NH₄⁺ contained in the inorganic salt precursor is utilized as N source to form Ni₂Mo₃N in the H₂ flow when elemental nickel is present. The high NH₃ flow rate required in the conventional temperature-programmed nitridation method is not necessary in this hydrogen thermal treatment method. Alumina-supported Ni₂Mo₃N has also been successfully prepared by this method. The resultant catalyst has better dispersion of Ni₂Mo₃N and exhibits higher catalytic activity compared to the catalyst prepared by the conventional method.