Partial oxidation of methane to synthesis gas: Novel catalysts based on neodymium–calcium cobaltate–nickelate complex oxides

Novel catalysts based on neodymium–calcium cobaltate–nickelate complex oxides for the partial oxidation of methane to synthesis gas have been synthesized and studied using catalyst precursors with the general formula NdCaCo 1– x Ni x O n ( x = 0, 0.2, 0.4, 0.6, 0.8, 1) prepared by the solid state synthesis method. It has been shown that the synthesized samples form a series of solid solutions with a K 2 NiF 4 structure at x ≤ 0.8 or a rhombically distorted K 2 NiF 4 structure at x = 1. The products of conversion of the resulting precursors in a methane–oxygen mixture at high temperatures have shown high methane conversions and synthesis gas yields. The highest values of these parameters have been achieved in the presence of catalysts synthesized by the reduction of NdCaCo 0.4 Ni 0.6 O n and NdCaNiO n precursors. The complete replacement of cobalt with nickel has led to an increase in the synthesis gas yield; however, it has been found that the resulting catalyst is prone to carbonization. It has been determined that an optimum nickel to cobalt ratio in the catalyst composition provides the formation of a carbonization-resistant catalyst.