Effect of nickel precursors on the performance of Ni/AlMCM-41 catalysts for n-dodecane hydroconversion

The bifunctional Ni/AlMCM-41 catalysts with 2.0 wt.% nickel loading were prepared by means of the wetness impregnation technique using three nickel precursors: nickel nitrate, alkaline tetraamine nickel nitrate and nickel citrate. The texture, crystal phase and surface metal/acidity functions were characterized by the techniques such as N-2-sorption, XRD, XPS, H-2-chemisorption, FT-IR and NH3-TPD. It was shown that the catalyst prepared with nickel citrate exhibited stronger metal-support interaction and higher metal dispersion than those prepared with nickel nitrate and alkaline tetraamine nickel nitrate. The intimate metal-acid interaction and the enhanced (de)hydrogenating capability of this catalyst led to the highest catalytic activity and isomerization selectivity in n-dodecane hydroconversion. (C) 2004 Elsevier B.V. All rights reserved.