In situ synthesis of Co–Ni nanocomposite catalysts of the partial oxidation of methane from K2NiF4-like complex oxide precursors

Oxide precursors NdCaCo1−xNixOn (x=0;0.2;0.4;0.6;0.8;1) are obtained by the solid-state synthesis method at 1100∘C. According to XRD analysis, the main components of these precursors are complex oxides with K2NiF4-like structure at x≤0.8 and with rhombically distorted K2NiF4 structure at x=1. A thermal decomposition of these precursors in the mixture of CH4/O2=2 at T ≥ 800∘C results in the formation of dense metal-oxide nanocomposite particles. As-obtained nanocomposites demonstrated a considerable catalytic activity and selectivity in the reaction of partial oxidation of methane; their catalytic properties vary non-monotonously with Co/Ni ratio. The maximum CH4 conversion and CO selectivity at 820∘C is demonstrated by the composite comprising Nd2O3, CaO, NiO and Ni metal nanoparticles.