Abstract: A process for isomerizing a feed comprising at least one aromatic compound containing eight carbon atoms per molecule is carried out in the presence of a catalyst comprising at least one modified zeolite with structure type EUO, at least one binder and at least one metal from group VIII of the periodic table, said catalyst having been prepared using a process which comprises the following in succession: a) a step for treatment of a zeolite with structure type EUO in the presence of at least one molecular compound containing at least one silicon atom, during which said compound, with a diameter greater than the maximum pore opening diameter in said zeolite, is deposited in the gas phase on the outer surface of said zeolite; b) at least one heat treatment step; c) forming said zeolite with a binder; d) at least one step for introducing at least one metal from group VIII of the periodic table onto a support based on said modified and formed zeolite.

Abstract: A process for isomerizing a feed comprising at least one aromatic compound containing eight carbon atoms per molecule is carried out in the presence of a catalyst comprising at least one modified zeolite with structure type EUO, at least one binder and at least one metal from group VIII of the periodic table, said catalyst having been prepared using a process which comprises the following in succession: a) a step for treatment of a zeolite with structure type EUO in the presence of at least one molecular compound containing at least one silicon atom, during which said compound, with a diameter greater than the maximum pore opening diameter in said zeolite, is deposited in the gas phase on the outer surface of said zeolite; b) at least one heat treatment step; c) forming said zeolite with a binder; d) at least one step for introducing at least one metal from group VIII of the periodic table onto a support based on said modified and formed zeolite.

Abstract: The invention concerns a process for skeletal isomerisation of linear olefins using a catalyst containing at least one pre-treated molecular sieve selected from the group formed by SAPO-31, SAPO-11, Theta-1, EU-1, omega zeolite, mordenite, Nu-10, Nu-86, Nu-87, ferrierite, ZSM-12 and ZSM-23.

Abstract: The invention concerns a process for skeletal isomerization of linear olefins using a catalyst containing at least one pre-treated molecular sieve selected from the group formed by SAPO-31, SAPO-11, Theta-1, EU-1, omega zeolite, mordenite, Nu-10, Nu-86, Nu-87, ferrierite, ZSM-12 and ZSM-23. The pre-treatment process consists in bringing the molecular sieve, which has a pore size of 0.4 to 0.8 nm, into contact with at least one hydrocarbon molecule containing 4 to 20 carbon atoms, at a space velocity of 0.1-45 h.sup.-1, a temperature of 300.degree.-550.degree. C. and at a pressure of 0.1-1 MPa, for 0.5-48 h, to deposit coke in the pores. The process is of particular application to one-dimensional sieves. It is preferably carried out outside the reaction zone. The invention also concerns a catalyst containing a pre-treated sieve, the sieve being selected from SAPO-31, SAPO-11, Theta-1, EU-1, omega zeolite, mordenite, ferrierite, Nu-10, Nu-86 and Nu-87.