Enhanced phenol hydroxylation with oxygen using a ceramic membrane distributor

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• 作者：Rizhi CHEN ; ^{rizhichen@njut.edu.cn} ; Yaohui BAO ; Weihong XING ; Wanqin JIN ; Nanping XU
• 关键词：Phenol ; Hydroxylation ; Oxygen ; Ceramic membrane ; Membrane distributor
• 刊名：Chinese Journal of Catalysis
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：34
• 期：1
• 页码：200-208
• 全文大小：1222 K

文摘

A CuO/TiO₂ catalyst was prepared by impregnation and characterized by X-ray diffraction, transmission electron microscopy, and temperature-programmed reduction. Two types of dispersed species formed on the TiO₂ surface, which were possibly isolated and polymeric CuO species. The CuO catalyst interacted strongly with the TiO₂ support. A porous ceramic membrane was used as a distributor to control the supply of oxygen in phenol hydroxylation over the CuO/TiO₂ catalyst. Compared to a direct feed of oxygen without a membrane, the yield of dihydroxybenzene (DHB) increased by 13 % using a porous ceramic membrane with a pore size of 0.5 ¦Ìm as an oxygen distributor. This is because the membrane distributor produced numerous small oxygen bubbles, increasing the volumetric oxygen transfer coefficient and gas-liquid mass transfer. Optimizing reaction conditions resulted in a yield of DHB of 2.5 % . Scanning electron microscope observation of the used ceramic membrane showed that it possessed excellent thermal and chemical stability.