A catalyst comprising: - a zirconia carrier (ZrO 2 ) - ruthenium - iron oxide (Fe 2 O 3 ) - at least one promoter (A) selected from the oxides of metals of groups IB, IIB and IIIa - at least one promoter (B) containing V, Ti, Hf, Zr or a mixture thereof, obtained by hydrolysis of at least one precursor P-B selected from the following metal arenes: V°(arene) 2 (I) V(arene) 2 AlCl 4 (II) M(η 6 -arene) p Al q X r (III) M(η 6 -arene) p' Al q' X r' R s (IV) wherein: - V represents vanadium, - Al represents aluminium, - M represents zirconium (Zr), hafnium (Hf), titanium (Ti) or mixtures thereof; - arene represents a benzene, or a benzene substituted by from 1 to 6 linear or branched C 1 -C 6 alkyl groups, or mixtures thereof; - X represents a halogen atom, selected from chlorine, bromine, fluorine, iodine, preferably chlorine; - R represents a linear or branched C 1 -C 15 alkyl group; - p represents a number ranging from 1 to 2; - q is a number ranging from 2 to 6, preferably from 2 to 3; - r is a number ranging from 8 to 20, preferably from 8 to 11; - p' represents a number ranging from 1 to 2; - q' is a number ranging from 2 to 6, preferably from 2 to 3; - r' is a number ranging from 2 to 20, preferably from 6 to 9; - s is a number ranging from 1 to 6, preferably 2. - a zirconia carrier (ZrO 2 ) - ruthenium - iron oxide (Fe 2 O 3 ) - at least one promoter (A) selected from the oxides of metals of groups IB, IIB and IIIa - at least one promoter (B) containing V, Ti, Hf, Zr or a mixture thereof, obtained by hydrolysis of at least one precursor P-B selected from the following metal arenes: V°(arene) 2 (I) V(arene) 2 AlCl 4 (II) M(η 6 -arene) p Al q X r (III) M(η 6 -arene) p' Al q' X r' R s (IV) wherein: - V represents vanadium, - Al represents aluminium, - M represents zirconium (Zr), hafnium (Hf), titanium (Ti) or mixtures thereof; - arene represents a benzene, or a benzene substituted by from 1 to 6 linear or branched C 1 -C 6 alkyl groups, or mixtures thereof; - X represents a halogen atom, selected from chlorine, bromine, fluorine, iodine, preferably chlorine; - R represents a linear or branched C 1 -C 15 alkyl group; - p represents a number ranging from 1 to 2; - q is a number ranging from 2 to 6, preferably from 2 to 3; - r is a number ranging from 8 to 20, preferably from 8 to 11; - p' represents a number ranging from 1 to 2; - q' is a number ranging from 2 to 6, preferably from 2 to 3; - r' is a number ranging from 2 to 20, preferably from 6 to 9; - s is a number ranging from 1 to 6, preferably 2. - V represents vanadium, - Al represents aluminium, - M represents zirconium (Zr), hafnium (Hf), titanium (Ti) or mixtures thereof; - arene represents a benzene, or a benzene substituted by from 1 to 6 linear or branched C 1 -C 6 alkyl groups, or mixtures thereof; - X represents a halogen atom, selected from chlorine, bromine, fluorine, iodine, preferably chlorine; - R represents a linear or branched C 1 -C 15 alkyl group; - p represents a number ranging from 1 to 2; - q is a number ranging from 2 to 6, preferably from 2 to 3; - r is a number ranging from 8 to 20, preferably from 8 to 11; - p' represents a number ranging from 1 to 2; - q' is a number ranging from 2 to 6, preferably from 2 to 3; - r' is a number ranging from 2 to 20, preferably from 6 to 9; - s is a number ranging from 1 to 6, preferably 2. <EOS>