Studies On Catalytic Reaction Of Hydroxylation Of Benzene And Phenol Over Fe Contained Catalysts With H₂O₂ As Oxidant

Phenol, Catechol and hydroquinone are important fine chemical intermediates and of high economical value. Until now the phenol production is still growing. The traditional methods of producing them always have multi-step reactions, complicated process and many by-products such as acetone and other contaminations. Therefore, one of the foremost challenges currently facing the chemical industry is to look for a cleaner, safer, and more environmentally friendly novel technics to substitute the traditional one. Up to now, there are lots of catalysts been widely investigated by people, some of them have better selectivity for the target product, but their activities are lower; some of them have higher catalytic activity, but as a whole their selectivities for aim product are lower; Others have higher catalytic activities and better selectivity for aim product, but their reaction rates are slower.Therefore, in order to resolve the above problem effectively, Our work mainly focused on the catalytic reaction system, preparation of the catalysts and enhancing the presented catalysts to increase the reaction rate and the aim product selectivity, and some following work have been done:(1) Design a new O/W micro-emulsion catalytic reaction system, which is composed of water, benzene, acetic acid, NaDBS and Fe(DDS)₃, with H₂O₂ for the direct hydroxylation of benzene to phenol. In this system, benzene layer can be dispersed well in the aqueous phase and to form lots of the micro-reactors, which is made of benzene and Fe(DDS)₃ mostly dissolved in it, H₂O₂ dissolved in the aqueous phase as an oxidant is brought into the micro-reactors by the surfactant NaDBS, and reacts with benzene. The phenol produced in the micro-reactors can be timely transferred to the aqueous phase because a large quantity of water can dissolve it far more than that of benzene, thus, this can efficiently minimize the successive reaction of phenol and enhance the selectivity for phenol. Besides, after the reaction completed, the un-reacted benzene and Fe(DDS)₃ catalyst dissolved in it can be easily recovered and reused...