Enhanced Isomerization Performance of Unsupported\nNi–Nb–O Catalyst for One-Step Hydrogenation of Jatropha\nOil to Alkanes

Biolipids and oil hydrogenation are\nprominent alternatives to petroleum-based\nfuels. Currently, the catalysts used are limited to deoxidation activity,\nresulting in the reaction products with a high content of <i>n</i>-alkanes and waxes, necessitating secondary treatment to\nincrease <i>iso</i>-alkane content. Herein, an unsupported\nNi–Nb–O catalyst with trifunctional capabilities (i.e.,\nhydrodeoxygenation, hydrocracking, and isomerization) was developed\nfor the efficient conversion of methyl stearate and jatropha oil into\nsmall molecular alkanes. The metal ratio significantly affects the\ncatalytic performance, in which Ni/Nb = 2:0.6 exhibited the highest\nisomerization activity. Moreover, 84% of the deoxidized products are\nC<sub>8</sub>–C<sub>17</sub> hydrocarbons, with 53.4% being\nisomeric hydrocarbons. The catalyst also demonstrated excellent stability,\nmaintaining 54% selectivity for C<sub>8</sub>–C<sub>17</sub> <i>iso</i>-alkanes in jatropha oil feedstock during 240\nh of operation.