Molybdenum nitride and carbide prepared from heteropolyacid II. Hydrodenitrogenation of indole

Hydrodenitrogenation (HDN) of indole has been studied over Mo2N prepared from MoO3, 12-molybdophosphoric acid (HPA) and MoO3 + P2O5 (a physical mixture of P2O5 and MoO3 with stoichiometry of P to Mo equal to that of HPA). It has been observed that Mo2N is an active catalyst for HDN of indole. It gave comparable activity (per unit mass) to that of Mo-Ni/gamma-Al2O3 but less hydrogen consumption. The initial activity of indole HDN was significantly increased by adding phosphorus in the catalysts despite its unfavorable pore and site blocking effects. However, P-containing Mo2N lost activity more readily than Mo2N itself, The deactivation did not result from carbon but probably was caused by nitrogen deposits from indole and loss of surface area, The bulk structure and morphology of the Mo2N catalysts were not changed after HND of indole, The reaction pathway did nor appear to be altered by adding phosphorus. (C) 1998 Academic Press.X1136sciescopu