Hydrocarbon conversion catalyst composition

A dewaxing or alkylaromatics isomerization catalyst composition, which consists essentially of:

• a dealuminated dried and calcined extrudate, obtained from a dried and calcined extrudate, wherein the extrudate, before drying and calcination, comprises a binder that is essentially free of alumina and which comprises both silica powder, wherein said silica powder comprises powder particles having a mean diameter between 10 μm and 200 μm, and a silica sol;
• EU-2 zeolite, wherein said EU-2 zeolite has a silica-to-alumina molar bulk ratio before the dealumination of said dried and calcined extrudate in the range of from 100 to 210;
• a plasticising agent;
• and water in an amount of at least 35% and not exceeding 60% by weight of the extrudate before drying and calcination;
• and
• a catalytic metal selected from the group consisting of platinum, palladium and nickel;
• wherein the dealumination of said dried and calcined extrudate is done by contacting said dried and calcined extrudate with an aqueous solution of fluorosilicate salt having a concentration of at least 0.005 mole of fluorosilicate salt/liter and at most 0.5 mole of fluorosilicate salt/liter and at a temperature in the range of from 10° C. to 120° C., and
• wherein the amount of said EU-2 zeolite present in said hydroconversion catalyst composition is at least 15% wt of said hydrocarbon conversion catalyst composition;
• and
• wherein the EU-2 zeolite is in the form of EU-2 zeolite particles, where the average aluminum concentration of the EU-2 zeolite particles is at least two times the aluminum concentration at the surface of the particles.