High surface area magnetic photocatalyst

Photocatalytic oxidation is a technique to convert hazardous organic contaminants to CO₂, water, and mineral acids. Several obstacles arise when applying this technology to full-scale operations. A new higher surface area photocatalyst was developed consisting of silica-coated strontium ferrite and Degussa P25 titanium dioxide dispersed in an acid catalyzed silica xerogel. Three types of this photocatalyst developed by modifying the concentration of hydrofluoric acid had measured BET surface areas of 177, 256, and 496 sq m/g. These photocatalysts were evaluated for their photocatalytic activity by oxidizing a 10 mg/L phenol solution. Resulting pseudo-first order reaction rate constants for reduction in nonpurgeable dissolved organic carbon were 0.189, 0.396, and 0.513/hr for the lowest to highest surface area photocatalyst compared to 0.194/hr for an equal mass of Degussa P25. This is an abstract of a paper presented at the AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).