Continuous Hydrogenation of Toluene over Sr- and PEG800-Modified Ni/γ-Al2O3 Catalysts

A series of γ‐Al2O3‐supported nickel‐based catalysts were evaluated in continuous hydrogenation of toluene. Sr‐ and poly(ethylene glycol) 800 (PEG800)‐modified Ni/γ‐Al2O3 catalysts provided the best activity with high conversion of toluene and selectivity for methylcyclohexane which was ascribed to the addition of Sr and PEG800 during the preparation process, resulting in smaller and highly dispersed Ni species on the surface and in the pores of γ‐Al2O3. Furthermore, the formation of SrCO3 and NiAl2O4 is believed to be advantageous for the dispersion and stabilization of the active Ni species, accounting for its good stability. A suitable cost‐effective catalyst with low Ni loading for hydrogenation of toluene under mild reaction conditions is required. A continuous process for the highly selective synthesis of methylcyclohexane via hydrogenation of toluene using γ‐Al2O3‐supported nickel‐based catalysts under such conditions is established. A Ni‐Sr‐PEG800/γ‐Al2O3 catalyst showed the best catalytic performance.