PHOSPHORUS PROMOTION OF NI(CO)-CONTAINING MO-FREE CATALYSTS IN QUINOLINE HYDRODENITROGENATION

Fresh and pretreated (in H2S/H-2, H-2, or He) unsupported nickel-and c obalt-phosphorus compounds were characterized by XRD and EM/EDAX and t ested in gas phase quinoline hydrodenitrogenation (643 K, 30 bar). Dur ing pretreatment or reaction, all compounds were transformed into Ni2P or Co2P. In addition, nickel supported on activated carbon, silica, s ilica/alumina, alumina, or NaY, to which phosphorus was added via thre e different methods, was tested in quinoline HDN, In most cases, the e ffect of phosphorus introduction was found to be strikingly beneficial , provided that the method of introduction was adjusted to the support : except with NaY, highly active molybdenum-free HDN catalysts could b e prepared, The activity of the supported phosphorus promoted catalyst s was ascribed to a new sulfur-free phase, consisting of highly disper sed Ni2P. (C) 1996 Academic Press, Inc.