A Comparison of the Reactivity of the Lattice Nitrogen in Tungsten Substituted Co Mo N and Ni Mo N.

The effect of the partial substitution of Mo with W in Co Mo N and Ni Mo N on ammonia synthesis activity and lattice nitrogen reactivity has been investigated. This is of interest as the coordination environment of lattice N is changed by this process. When tungsten was introduced into the metal nitrides by substitution of Mo atoms, the catalytic performance was observed to have decreased.

Citrate-gel preparation and ammonia synthesis activity of compounds in the quaternary (Ni,M)MoN (M = Cu or Fe) systems.

Single phase solid solutions based on copper and iron substitution into the nickel sites of NiMoN are produced using a citrate gel approach followed by ammonolysis. These metal nitrides show good ammonia synthesis activity at 500 °C and ambient pressure. The activity fell with copper content and increased with iron content, although these changes appear to be related to the surface areas of the catalysts.