The effect of metal distribution across pellets on the activity of nickel–tungsten hydrotreating catalysts

Nickel–tungsten‐based hydrotreating catalysts have been prepared with different metals impregnation profiles and tested for the hydrodesulphurisation, hydrodenitrogenation and hydrogenation of model compounds. Penetration of the catalyst by the model compounds depends on the pore structure of the support and determines activity. Best performance is associated with optimal Ni:W ratios dished across the active region of the catalyst rather than with an even impregnation across all of the support.