Pyridine hydrodenitrogenation catalysed, under atmospheric pressure, by Niand Mo oxynitrides and MoNi, MoPNi, AlNi and AlPNi mixed oxynitrides

Hydrodenitrogenation of pyridine has been realised, under atmospheric press ure, in the presence of oxynitride catalysts of molybdenum, nickel and thei r solid solutions as well as on mixed catalysts MoNi, MoPNi ACNi and AlPNi. Tn all cases, the main reaction products are n-pentane and N-pentylpiperid ine, at any conversion. Kinetic results suggest that the conversion of pyri dine, on nickel oxynitride, proceeds through successive steps with hydrogen ation as rate-limiting. Molybdenum oxynitride and Mo-Ni-N solid solutions tested in the temperature range 500 degrees C-540 degrees C, showed a good structural and catalytic stability, but a low catalytic activity. On the other hand, nickel oxynitri de catalyst yielded higher activity at much lower temperatures (190 degrees C - 250 degrees C). X-rays analysis indicates that the used catalyst was e ntirely reduced to metallic nickel, which is the active phase. Under the sa me experimental conditions, mixed catalysts are relatively less active but more selective than nickel oxynitride into n-pentane formation.