PHOTOCATALYTIC DEGRADATION OF TRANS-CINNAMIC, DIHYDROCINNAMIC, TRANS-CAFFEIC, AND DIHYDROCAFFEIC ACIDS AND CHARACTERIZATION OF THE PRODUCTS

Abstract

Catalysed degradation of aqueous solutions of cinnamic 1, dihydrocinnamic 2, dihydrocaffeic 3 and trans-caffeic 4 acids in the presence of (TiO₂) and UV radiation and the products identified by HPLC, and after treatment with diazomethane by GC-MS have been studied. A pH range of 3 to 11 was used. The four acids, in the presence of TiO₂ in the dark, underwent little degradation. Extended irradiation of all the acids in the presence of TiO₂ produced complete degradation as shown by TOC measurements. Initially the volume of carbon dioxide produced rose steadily to a constant value.

Keywords:

• trans-Cinnamic
• Dihydrocinnamic
• trans-Caffeic
• Dihydrocaffeic acids
• Photocatalysed degradation
• Titanium dioxide
• TOC

Acknowledgments