Hydroalkylation of benzene and ethylbenzene over Ru-and Ni-containing zeolite catalysts : novel catalytic route for ethylcyclohexylbenzene synthesis

Abstract The reaction of benzene and ethylbenzene has been studied over zeolite catalysts with different structural type (BEA, MFI), Si/Al ratio (10 – 200 for BEA) and Ru and Ni contents (0.5 – 1%) in the temperature range of 150 – 230 0 C, under 0.2 – 1 MPa and WHSV of 1 – 64 g/g*h. The main reaction pathways were found to include benzene and ethylbenzene hydrogenation towards cyclohexane and ethylcyclohexane, hydroalkylation into cyclohexylbenzene, ethylcyclohexylbenzene and diethylcyclohexylbenzene and formation of ethylbiphenyls or diethylbiphenyls followed by hydrogenation. The major reaction products were para- and meta-ethylcyclohexylbenzenes. The results have demonstrated that hydroalkylation of benzene and ethylbenzene over metal containing zeolites is a perspective route for synthesis of ethylcyclohexylbenzene, which can find application in production of phenylstyrene.