Synthesis of copper bearing MFI zeolites and their activity in wet peroxide oxidation of phenol

✍ Scribed by S Valange; Z Gabelica; M Abdellaoui; J.M Clacens; J Barrault

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 143 KB
• Volume: 30
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(99)00031-1

✦ Synopsis

A series of MFI-type metallosilicates (M=Al, Ga, Zn, Cu or their admixtures), prepared through original procedures involving direct crystallization of TPABr-containing silica gels admixed with the corresponding metallic nitrates and various mineralizing agents, has been tested as catalysts for oxidation of phenol with hydrogen peroxide in aqueous solution. The zeolites crystallized in the presence of Cu2+-methylamine complex proved the most active for the total organic carbon conversion and the most stable in terms of copper leaching. An optimum amount of acid sites generated by the presence of specific amounts of framework Ga or Al appeared to be a prerequisite to generate stable and active cationic copper species. The best results (78% phenol conversion, 61% total phenolic carbon conversion after 4 h on stream) were obtained so far with 0.5 g of an MFI catalyst containing 0.56 wt.% of Cu, 2 wt.% of Zn and 0.25 wt.% of Al. Our results show that phenol is mainly oxidized over the solid catalyst surface and that soluble copper in aqueous phase plays a negligible role.