CHARACTERIZATION OF POTASSIUM-DOPED NICKEL-CATALYSTS AND ACTIVITY FOR SELECTIVE HYDROGENATION OF 1,6-HEXANEDINITRILE

Studies of the chemical preparation, BET surface areas, X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), temperature-programmed reduction (TPR) and catalytic activities of several nickel catalysts were carried out for the catalytic hydrogenation of adiponitrile, in a continuous process at 1 atm pressure, 443 K, and in the absence of ammonia. Surface areas decrease with NiO reduction temperature. XRD, XPS and TPR measurements detect NiO incipient reduction at 473-498 K, a NiO reducibility inhibitor character for potassium, and 99.9% reduction degrees above 573 K. Selectivities of 100% with respect to 6-aminohexanenitrile are obtained at 60% conversion for catalysts with potassium contents of 10.5 X 10(-4) g K2O/g Ni.