Abstract: The invention refers to a process for the obtainment of a catalyst useful in the isomerization of light paraffins, fundamentally based on acid treatment of a synthetic mordenite at temperatures between 40.degree. and 100.degree. C. followed by treatment with steam-air at temperatures between 300.degree. and 600.degree. C. which make it possible to optimize the SiO.sub.2 /Al.sub.2 O.sub.3 framework ratio and the amount of extraframework aluminum of the zeolite. The mordenite thus obtained is mixed with an inorganic refractory oxide such as Al.sub.2 O.sub.3 and a metal of group VIII, basically Pt, is added in an amount between 0.1 and 0.5% by weight referred to the final catalyst.The catalyst has been tested in the isomerization of light refinery fractions (C.sub.5 and C.sub.6) and has a high activity and selectivity of branched isomers with a low production of gases and a high octane number for the light gasoline obtained.

Abstract: The invention refers to a process for the obtainment of a catalyst useful in the isomerization of light paraffins, fundamentally based on acid treatment of a synthetic mordenite at temperatures between 40.degree. and 100.degree. C. followed by treatment with steam-air at temperatures between 300.degree. and 600.degree. C. which makes is possible to optimize the SiO.sub.2 Al.sub.2 O.sub.3 framework ratio and the amount of extraframework aluminum of the zeolite. The mordenite thus obtained is mixed with an inorganic refractory oxide such as Al.sub.2 O.sub.3 and a metal of group VIII, basically Pt, is added in an amount between 0.1 and 0.5% by weight referred to the final catalyst.The catalyst has been tested in the isomerization of light refinery fractions (C.sub.5 and C.sub.6) and has a high activity and selectively of branched isomers with a low production of gases and a high octane number for the light gasoline obtained.