The invention concerns a process for the preparation of a catalyst starting from a pre-catalyst comprising at least one catalytic metal and a support, said pre-catalyst having undergone a heat treatment at at least 60° C. without calcining, in which process said pre-catalyst is impregnated with a basic solution having a pH of more than 7.5 and containing at least one molecule in the zwitterionic form, and the impregnated pre-catalyst is dried at a temperature of at most 240° C. without subsequent calcining.;The molecule in the zeolite form is selected from the group formed by amino-alcohol acids containing secondary or tertiary amine groups and containing at least one carboxylic acid function (and preferably only one) and at least one alcohol function. It is bicine or tricine, for example.;The invention also concerns the catalyst prepared using this process, and its use in hydrotreatment and/or hydroconversion.
