Reforming catalyst preparation by dry impregnation

A method of preparing a reforming catalyst comprising a group VIII metal, a halogen, at least one group VIIB or group IVA metal, and a refractory oxide support, said method comprising:

• a) incorporating of the group VIII and VIIB metals by preparing a dry impregnation aqueous solution, comprising either a group VIII metal or a group VIII metal and a group VIIB metal, ammonia either in solution or in gas form, and at least one complexing agent that is EDTA or derivatives thereof, at least bidentate primary amine complexes, secondary amine complexes or pyridine ring derivatives,
• b) aging said dry impregnation aqueous solution obtained at the end of (a), over a period of time ranging between 5 minutes and 24 hours, at a temperature ranging between 15° C. and 100° C.,
• c) dry impregnating of the support by the aged dry impregnation aqueous solution obtained at the end of b),
• d) maturing the impregnated support obtained at the end of c), said maturation being carried out in a humid medium over a period of time ranging between 30 minutes and 48 hours,
• e) drying the impregnated support obtained at the end of d), at a drying temperature between 80° C. and 200° C., over a period of time between 5 minutes and 5 days,
• f), calcining at a calcination temperature between 300° C. and 850° C. and a calcination time between 5 minutes and 20 hours,
• incorporating the group IVA metal, if present, during or subsequent to preparation of the support.