HDN OF 1-4 TETRAHYDROQUINOLINE OVER MONXOY AND NBNXOY - EFFECT OF TRANSITION-METAL, SOLVENT AND AMMONIA

Oxynitrides of early transition metals are bifunctional catalysts acti ve in hydrodenitrogenation (HDN). The strength of the hydrogenating fu nction and the acidic properties of molybdenum and niobium oxynitrides were investigated, as well as the inhibiting effect of ammonia and th e effect of solvent (cyclohexane or tetradecane) on HDN of 1,2,3,4-tet rahydroquinoline (1-4 THQ). Even under high hydrogen pressure (4.5 MPa ) the reaction was found to be able to proceed without hydrogenation o f the aromatic cycle of 1-4 THQ before C-N bond scission, which is not the case over sulfided NiMo supported catalysts in HDN. Experiments i n presence of ammonia permitted to support a bifunctional dual site co ncept.