KINETICS OF THE HYDRODENITROGENATION OF DECAHYDROQUINOLINE OVER NIMO(P) AL2O3 CATALYSTS/

Cis- and trans-propylcyclohexylamine were identified as primary reacti on intermediates of the aliphatic C-N bond cleavage in the hydrodenitr ogenation (HDN) network of decahydroquinoline (DHQ). The kinetic param eters of the HDN network were calculated assuming a Langmuir-Hinshelwo od mechanism. Three kinds of catalytic sites could be distinguished: a liphatic C(sp(3))-N bond cleavage, (de)hydrogenation of a (aromatic) h eterocyclic ring, and alkene hydrogenation. The adsorption constants o ver NiMo/Al2O3 and NiMoP/Al2O3 catalysts were the same for the C(sp(3) )-N bond cleavage site, while different for the hydrogenation sites. T he decreased rate constant of the first C(sp(3))-N bond cleavage accou nts for the negative effect of phosphorus in the HDN of DHQ. Introduct ion of Ni to a Mo(P)/Al2O3 catalyst increased the rate constant of the C(sp(3))-N bond cleavage by a factor of 2, and that of alkene hydroge nation by a factor of 6.