Photooxidation of Dimethyl Methylphosphonate on TiO₂ Powder

The photooxidation of dimethyl methylphosphonate (DMMP) on powdered TiO 2 has been studied using UV irradiation in the range 2.1 eV to 5.0 eV. It has been found that the P−CH 3 and the P−OCH 3 moieties are destroyed together by photooxidation, producing adsorbed CO and CO 2 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 PO 3 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 TiO 2 surface.