Use of Nb2O5 as nickel passivating agent:: characterisation of the Ni/Nb2O5/SiO2 system

Niobia-modified silica was used as support for nickel-based catalysts. Catalysts with different nickel loading were prepared by successive incipient-wetness impregnation of toluenic nickel octanoate solutions. The samples were characterised. after both calcination and reduction by TEM-EDX techniques and tested in the ethane hydrogenolysis. Their catalytic behaviour was compared to that of related silica-supported nickel catalysts. A high suppression of hydrogenolysis activity (93-99%) was determined for the niobia-modified silica-supported nickel catalysts which do not show nickel particles on silica. (C) 2002 Elsevier Science B.V. All rights reserved.