Photooxidation of dimethyl methylphosphonate on TiO2 powder

The photooxidation of dimethyl methylphosphonate (DMMP) on powdered TiO2 has been studied using UV irradiation in the range 2.1 eV to 5.0 eV. It has been found that the P-CH3 and the P-OCH3 moieties are destroyed together by photooxidation, producing adsorbed CO and CO2 as well as formate ions and water. By working at 200 K the photooxidation process has been studied alone, whereas at room temperature both hydrolysis and photooxidation will occur together. An adsorbed PO3 species is the final phosphorus-containing photooxidation product. High coverages of DMMP are not photooxidized due to site blockage for O-2 adsorption on the TiO2 surface.