C-4 and C-5 cuts from FCC units can be useful in the preparation of oxygenates such as MTBE, ETBE, and TAME. Removal of the nitriles and diolefins present in these feedstocks is required to avoid poisoning of the etherification catalyst. Technological options include water washing and adsorption for nitriles and selective hydrogenation for the diolefins. PDVSA Intevep has developed several methods to address this problem. One includes nitrile removal by adsorption (part 1 of this work, Ramirez-Corredores, M. M.; Hernandez, Z.; Guerra, J.; Medina, J.; Alvarez, R. Adsorption, manuscript submitted), and two others are based on catalytic conversion. In this paper, we discuss the critical features of a catalytic system for the simultaneous hydrogenation of nitriles and diolefins. A very high selectivity so as to inhibit saturation of the mono-olefins is also desired in such catalyst. Different metal phases and support materials were evaluated and characterized. Both model and real feedstocks were considered for evaluation at the bench and pilot-plant scales. Characterization methods used include chemical composition analysis, temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). A particular oxidation state of the metal phase and the nitrile adsorption capability of the support material were found to be the key properties of the developed catalytic system.