Thermal stability of catalyst for ammonia synthesis based on cobalt molybdenum nitrides

The formation and stability of an ammonia synthesis catalyst, based on cobalt molybdenum nitrides, were studied. The activation process of the catalyst was examined by in situ X-ray diffractometry. The thermal stability of obtained active phase of the catalyst was tested at 700 °C under ammonia atmosphere, N 2 /H 2 mixture and under pure hydrogen. The presence of Co 2 Mo 3 N and Co 3 Mo 3 N phases in the catalyst was confirmed. The phase composition was stable in a long-term test performed under nitrogen/hydrogen atmosphere. Co 3 Mo 3 N phase decomposed into Co 6 Mo 6 N after exposure to pure hydrogen.