Patent ID: 7563743

Claim:
A catalyst that comprises at least one hydro-dehydrogenating element that is selected from the group consisting of the elements of group VIB and group VIII of the periodic table, 0.01 to 5.5% by weight of oxide of a dopant that is selected from among phosphorus, boron and silicon, and a non-zeolitic substrate with a silica-alumina base that contains a quantity of more than 15% by weight and less than or equal to 95% by weight of silica (SiO 2 ), whereby said catalyst exhibits the following characteristics: a) a mean pore diameter, measured by mercury porosimetry, of between 20 and 140 Å, b) a total pore volume, measured by mercury porosimetry, of between 0.1 ml/g and 0.5 ml/g, c) a total pore volume, measured by nitrogen porosimetry, of between 0.1 ml/g and 0.5 ml/g, d) a BET specific surface area of between 100 and 550 m 2 /g, e) a pore volume, measured by mercury porosimetry, encompassed in the pores with a diameter of more than 140 Å, of less than 0.1 ml/g, f) a pore volume, measured by mercury porosimetry, encompassed in the pores with a diameter of more than 160 Å, of less than 0.1 ml/g, g) a pore volume, measured by mercury porosimetry, encompassed in the pores with a diameter of more than 200 Å, of less than 0.1 ml/g, h) a pore volume, measured by mercury porosimetry, encompassed in the pores with a diameter of more than 500 Å, of at least about 0.03 ml/g and of less than 0.09 ml/g, i) an X-ray diffraction diagram that contains at least the main lines that are characteristic of at least one of the transition aluminas contained in the group that consists of the alpha-, rho-, chi-, eta-, gamma-, kappa-, theta- and delta-aluminas, j) a packing density of catalysts of more than 0.75 g/cm 3 .