Method of improving selective hydrogenation of unsaturated hydrocarbon in aromatic fraction through catalyst pretreatment

A method for preparing a selective hydrogenation catalyst for an unsaturated hydrocarbon in an aromatic fraction, which comprises the steps of:

• step a) providing a calcined catalyst containing nickel and molybdenum;
• step b) sulfiding the calcined catalyst containing nickel and molybdenum to give a sulfided catalyst containing nickel and molybdenum;
• step c) carrying out an oxidation treatment of the sulfided catalyst containing nickel and molybdenum at a temperature exceeding 250° C. and below 700° C. to give an oxidized catalyst containing nickel and molybdenum;
• and
• step d) carrying out a reduction treatment of the oxidized catalyst containing nickel and molybdenum to give a reduced catalyst containing nickel and molybdenum.