Mechanochemical synthesis of β-NiMoO4 as a precursor of bulk highly dispersed catalyst for the hydrocracking of oil fractions

Abstract

The possibility of synthesizing bulk catalysts by means of mechanochemical activation (MCA), the basis for wasteless technologies for the production of catalysts with particle sizes less than 10 μm, is demonstrated. The precursors of Ni-Mo catalysts for hydrogenation processes are synthesized by MCA. The chemical and phase composition and specific surface area of mechanically activated composites with Ni: Mo atomic ratio = 1.0 and 1.4 are studied by DTA, XRD, TPR, and low-temperature adsorption. It is established that during the simultaneous MCA of Ni- and Mo-containing salts, solid-state reactions yield complex X-ray amorphous compounds that after calcination at 520°C form nickel molybdates composed almost entirely of highly active modified β-NiMoO4, the sulfidation of which produces MoS2 and Ni3S2 phases. Comparative testing of sulfide catalysts (i.e., bulk (Ni: Mo = 1.4) and industrial supported) in model reactions of the conversion of 1-methylnaphthalene and dibenzothiophene was performed at a temperature of 350°C, a pressure of 3.5 MPa, a feedstock hourly space velocity of 2 h−1, and a hydrogen/feedstock ratio of 600. Based on the composition of the 1-methylnaphthalene and dibenzothiophene conversion products while using industrial and bulk catalysts, it is concluded that the bulk catalyst exhibits higher hydrogenating activity.