Simultaneous n-hexane isomerization and benzene saturation over Pt/nano-crystalline zeolite beta

Hydroisomerization of n-hexane simultaneously proceeding with benzene saturation over platinum impregnated nano-crystalline zeolite beta (Si/Al = 25) at 1.0 MPa and 573-673 K was studied. The feed contained 30 wt% benzene. The synthesized catalyst was characterized by various techniques, e. g., powder X-ray diffraction, IR spectroscopy, thermal analysis, scanning electron microscopy and nitrogen adsorption. At the operating conditions used, total saturation of benzene with 95% selectivity to cyclohexane (CH) and methylcyclopentane (MCP) was observed. n-Hexane conversion increased with temperature whether benzene was present or not during the reaction. However, in the presence of benzene, n-hexane conversions as well as isomer selectivities were observed to be lower. This was attributed to reduced availability of acid sites by predominating benzene adsorption. Formation of carbenium ion on an acid site is questioned and plausible mechanism has been suggested.