NICKEL NIOBIA INTERACTION-INDUCED BY THE REDUCTION OF NINB2O6 SUPPORTED ON SIO2

Nickel niobate (NiNb2O6) supported on SiO2 was prepared by a chemical mixing method using mixed Ni and Nb citrate solutions. X-ray diffraction study showed that the NiNb2O6 compound was reduced to Ni metal and NbO2 after H-2 treatment at 600-degrees-C, and a strong Ni-niobia interaction was induced after the decomposition of the compound: the ethane hydrogenolysis activity was suppressed severely after high temperature reduction at 600-degrees-C, and recovered by O2 treatment at 500-degrees-C followed by low-temperature reduction at 200-degrees-C. The selectivity of cyclohexane dehydrogenation was improved significantly by the Ni-niobia interaction, if compared with unpromoted Ni/SiO2 catalyst, and the structural change and catalytic behaviors were compared with those of Rh double oxides such as RhNbO4.