Bifunctional Palladium (Pd) supported Y-zeolite, with SiO₂/Al₂O₃ ratios 5, 12, 30 and 60, prepared by impregnation method were used for hydroalkylation of benzene. It is found that the reaction condition and catalyst composition influence the hydroalkylation activity and cyclohexylbenzene (CHB) selectivity. CHB selectivity of a hydroalkylation catalyst can be determined by the destiny of the intermediate cyclohexene formed by partial hydrogenation of benzene on the metal site of the catalyst. That is, if the intermediate cyclohexene hydrogenates to cyclohexane on the metal site, the selectivity for CHB decreases whereas, if the intermediate cyclohexene is alkylated with benzene on the acid sites, the selectivity for CHB increases. Thus, there is a requirement of optimum balance of exposed metal and acid sites of the catalyst for enhancing CHB selectivity. At 42.2% of benzene conversion, Pd (0.2 wt%)/HY5 (SiO₂/Al₂O₃ = 5) catalyst gave a CHB selectivity of 75% in comparison to 70.3% for the best patented catalyst. Furthermore, a kinetic model has been developed for the hydroalkylation of benzene, assuming dissociative, non-competitive addition of hydrogen. Finally, the developed kinetic model along with experimental data was used to study the effect of mole ratio of acid sites to exposed metal sites of Pd/HY catalyst system for hydroalkylation reaction. Based on these results, the ratio of number of acid sites to exposed metal sites can be tuned to maximize CHB yield.

具有SiO ₂ / Al ₂ O _3的双功能钯（Pd）负载Y沸石通过浸渍法制备的比例为5、12、30和60的化合物用于苯的加氢烷基化。发现反应条件和催化剂组成影响加氢烷基化活性和环己基苯（CHB）的选择性。加氢烷基化催化剂的CHB选择性可以通过中间体环己烯的命运来确定，该中间体是由苯在催化剂的金属位点上部分氢化而形成的。即，如果中间环己烯在金属位点上氢化成环己烷，则对CHB的选择性降低，而如果中间环己烯在酸位点上被苯烷基化，则对CHB的选择性增加。因此，为了提高CHB的选择性，需要使催化剂的暴露金属和酸性位点达到最佳平衡。苯转化率为42.2％时，Pd（0.2 wt％）/ HY5（SiO₂ / Al ₂ O ₃  = 5）催化剂的CHB选择性为75％，而获得最佳专利的催化剂的CHB选择性为70.3％。此外，已经建立了用于苯的加氢烷基化的动力学模型，假定氢是解离的，非竞争性的。最后，将动力学模型与实验数据一起用于研究加氢烷基化反应中Pd / HY催化剂体系中酸性部位与裸露金属部位的摩尔比的影响。基于这些结果，可以调整酸位点与暴露的金属位点的比例，以使CHB产量最大化。