Catalytic wet oxidation of phenol: The role of promoter and ceramic support

Abstract

Complete mineralization of phenol has been achieved over a cerium–manganese catalyst, doped with potassium, supported on a modified zeolite with a high surface area, under very mild conditions (110 °C, PO2 = 0.5 MPa). This newly developed supported catalyst restricts the formation of bulk polymeric species on the surface, thus increasing the lifetime of the catalyst. It demonstrates superior textural, structural and surface oxygen properties compared with the reference cerium–manganese oxide catalyst. The supported catalyst maintains not only the high surface area but also the nanoparticle size during the catalytic run, thereby providing the full availability of the surface for reacting molecules. The geometry of the catalyst is modified electronically by the addition of potassium, and the zeolite addition restricts the conversion of Ce, Mn and K to higher oxidation states, thereby maintaining the geometry of catalytic active sites. The performance measured with this novel catalyst indicates a major improvement in the efficient application of the catalytic wet oxidation process for complete purification of a complex waste stream.