Abstract: The invention concerns a catalyst containing a support comprising at least one binder and at least one zeolite having at least one series of channels the opening of which is defined by a ring containing 12 oxygen atoms, said catalyst comprising phosphorus, at least one C1-C4 dialkyl succinate, acetic acid and a hydrodehydrogenating function comprising at least one element from group VIB and at least one element from group VIII, the Raman spectrum of the catalyst comprising bands at 990 and/or 974 cm?1, characteristic of at least one Keggin heteropolyanion, the characteristic bands of said succinate and the characteristic principal band of acetic acid at 896 cm?1. The invention also concerns the process for preparing the catalyst and its use in hydroconversion.

Abstract: A process for the preparation of a catalyst from a catalytic precursor comprising a support based on alumina and/or silica-alumina and/or zeolite and comprising at least one element of group VIB and optionally at least one element of group VIII, by impregnation of said precursor with a solution of a C1-C4 dialkyl succinate. An impregnation step for impregnation of said precursor which is dried, calcined or regenerated, with at least one solution containing at least one carboxylic acid other than acetic acid, then maturing and drying at a temperature less than or equal to 200° C., optionally a heat treatment at a temperature lower than 350° C., followed by an impregnation step with a solution containing at least one C1-C4 dialkyl succinate followed by maturing and drying at a temperature less than 200° C. without subsequent calcination step. The catalyst is used in hydrotreatment and/or hydroconversion.

Abstract: A method of regenerating an enzymatic catalyst arranged in a reactor includes a mineral support based on metal oxide and at least one enzyme, wherein it contains at least one step of detachment of the spent enzymes by solvation by scavenging of the catalyst using at least one ionic surfactant, and at least one step of re-attachment of active enzymes by scavenging of the purified support with at least one solution of active enzymes, the two steps being performed in situ within the reactor.