Molybdenum oxide nitride (denoted as Mo(O,N)3) was obtained by ammonolysis of α-MoO3 with gaseous ammonia. Electronic and geometric structure, reducibility, and conductivity of Mo(O,N)3 were investigated by XRD, XAS, UV-Vis spectroscopy, and impedance measurements. Catalytic performance in selective propene oxidation was determined by online mass spectrometry und gas chromatography. Upon incorporation of nitrogen, Mo(O,N)3 maintained the characteristic layer structure of α-MoO3. XRD analysis showed an increased structural disorder in the layers while nitrogen is removed from the lattice of Mo(O,N)3 at temperatures above ~600 K. Compared to regular α-MoO3, Mo(O,N)3 exhibited a higher electronic and ionic conductivity and an onset of reduction in propene at lower temperatures. Surprisingly, α-MoO3 and Mo(O,N)3 exhibited no detectable differences in onset temperatures of propene oxidation and catalytic selectivity or activity. Apparently, the increased reducibility, oxygen mobility, and conductivity of Mo(O,N)3 compared to α-MoO3 had no effect on the catalytic behavior of the two catalysts. The results presented confirm the suitability of molybdenum oxide nitrides as model systems for studying bulk contributions to selective oxidation.

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Molybdenum‐based mixed oxides represent well‐known model catalysts for the selective oxidation of light alkenes. Here, the anion lattice of (Mo,V)5O14 was for the first time modified by substituting oxygen ions with nitrogen ions. Investigations by XRD analysis, X‐ray absorption spectroscopy, and FTIR spectroscopy revealed that the incorporation of nitrogen in the structure of Mo5O14 proceeded without changing the average valence of metal centers. Additionally, impedance spectroscopy confirmed the formation of oxygen vacancies. Significant changes in conductivities remained after the removal of nitrogen. Temperature‐programmed reduction measurements were performed to investigate oxygen mobility. The enhanced reducibility of oxide nitrides correlated with the increased conductivity. Catalytic performance in selective propene oxidation was determined by online mass spectrometry und gas chromatography at different temperatures. Selectivity towards acrolein increased with increasing conductivity whereas the formation of total oxidation products COx decreased.

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