Study On The Dehydrogenation Catalyst For Preparing Ortho-phenylphenol From Cyclohexanone Dimer

Ortho-phenylphenol (hereinafter abbreviated as OPP) is a high-valued fine chemical with various applications as intermediate for dye products, photographic chemicals, rubber additives and low-toxicity bactericides in industry.Traditionally OPP was produced chiefly as a by-product in the alkali hydrolysis of chlorobenzene to phenol. However, this process for phenol production has been taken over by much cleaner cumene process, consequently reducing the supply of OPP as the by-product despite the increasing demand for the compound for use in surfactants and disinfectants and giving rise to the necessity to develop a new process for the production of OPP per se in order to compensate for the reduction in the supply of the by-product. Among those alternative technologies developed for OPP, catalytic dehydrogenation process of cyclohexanone dimmer attracts much more attention in research and industrial application fields. But many problems are also encountered in the dehydrogenation process such as poor activity behavior of catalysts, and bad reproducibility of catalyst preparation. It is too difficult to maintain a high selectivity and high conversion for a prolonged period of time, especially when platinum is used as the active component for catalyst in this process, the active life of the dehydrogenation catalyst is relatively short while the selectivity for OPP is not satisfactory. So it is very important to prepare a dehydrogenation catalyst with a prolonged life and high selectivity for the production of OPP.In this dissertation, we tookγ-Al2O3 as support and Pt as active component which was carried on the support and systemically investigated the dependence of...