Development of New Catalytic Materials for Hydrogen Energy on the Basis of Ni–Co Nanoalloys on the Surface of Nanostructured (Ni)CoAl2O4 Spinels and Their Study in the Reaction of Dry Reforming of Methane

NixCo1 – xAl2O4 (x = 0−0.5) catalysts were prepared by coprecipitation of Ni, Co, and Al nitrate salt solutions. Heat treatment of the resulting xerogel at 700°C in air resulted in aluminum oxide with a spinel structure, in which nickel and cobalt ions were stabilized. Studying in situ reduction of these precursors in a hydrogen-containing gas mixture at 700°C by X-ray diffraction analysis and ex situ after preliminary reduction in a hydrogen-containing gas mixture and further operation under reaction conditions showed that 3–4 mm ensembles of Ni–Co alloy particles are formed on the surface of the spinel. The influence of catalyst composition and duration of their testing on catalytic properties in the reaction of dry methane reforming (DMR) was investigated. The Ni0.35Co0.65Al2O4 catalyst showed stable performance in the DMR reaction for 20 h with a CH4 conversion of 76% and a H2 yield of 42% (T = 700°C, τ = 30 ms). The high catalytic activity of the obtained catalysts in DMR is due to the formation of highly dispersed alloy Ni–Co nanoparticles of the active phase in an amount of 17–18 wt % on an initially large specific surface area of spinel, which is by nickel and cobalt ions and has mobile bulk oxygen in a reduced state.