Catalyst for the hydroisomerization of contaminated hydrocarbon feedstock

A catalyst system for treating sulfur and nitrogen contaminated hydrocarbon feedstock includes a matrix, at least one support medium substantially uniformly distributed through said matrix and comprising a silica alumina molecular sieve material having a silica/alumina ratio of at least about 20, a first catalytically active metal phase supported on said support medium, said first catalytically active metal phase comprising a first metal and a second metal each selected from group VIII of the Periodic Table of Elements, said first metal being different from said second metal, a second catalytically active metal phase supported on said matrix, said second catalytically active metal phase comprising a third metal and a fourth metal each selected from group VIII of the Periodic Table of Elements and a fifth metal selected from group VIb of the Periodic Table of Elements, said third metal being different from said fourth metal. The catalyst system has a higher ratio of silica to alumina in the support medium allowing reduced amounts of active metals.