Hydrogenation of toluene over Ni-loaded catalysts containing ZSM -5 zeolite.

ZSM-5 zeolite and aluminum oxide (50:50) nickel catalysts (8 wt.% of nickel oxide) were tested for activity in the hydrogenation of toluene. The hydrogenating function of the catalysts was modified by additional incorporation of 4 wt.% of NiO or 0.2 wt.% of RuO2. The catalysts also differed in the extent of ion exchange in the zeolite. Determinations were carried out in a through-flow system at 3.5 MPa and 160 to 320 °C (LHSV=3 h-1; H2:CH=350 Nm3/m3). It was found that the hydrogenation activity of the nickel loaded catalysts increased noticeably when the amt of NiO rose from 8 to 12 wt.%. The decrease in the metal to acid ratio in the catalysts brought about an increase in the selectivity of cyclopentane derivatives. The modification of the hydrogenating function of 8 wt.% of NiO catalyst with 0.2-wt.% of RuO2 yielded a catalyst with an activity which allowed hydrogenation of toluene at considerably lower temps.