Process for converting paraffin with modified zirconia catalyst

A process for converting paraffin comprising the steps of:

• (i) providing feed containing n-pentane, n-hexane and more than 2 vol % n-heptane based on the volume of the feed;
• and
• (ii) subjecting the feed to isomerization of n-heptane with a modified zirconia catalyst, wherein the modified zirconia catalyst comprises zirconium oxide, sulfate ions, a first metal component and a second metal component, the first metal component contains at least one of Group III A (IUPAC 13) metal elements or a combination thereof at an amount of between 0.1 wt % and 15 wt % based on the weight of the catalyst, the second metal component contains a substance selected from a group consisting of platinum, platinum oxide, palladium, palladium oxide and a combination thereof at an amount of between 0.2 wt % and 3.0 wt % based on the weight of the catalyst, and sulfate ions contain sulfur at an amount of less than 1.0 wt % based on the weight of the catalyst;
• wherein the i-C7 selectivity is higher than 80% as the conversion rate rises to 80%.