Acetaldehyde photochemistry on TiO 2(1 1 0)

Abstract

The ultraviolet (UV) photon induced decomposition of acetaldehyde adsorbed on the oxidized rutile TiO 2(1 1 0) surface was studied with photon stimulated desorption (PSD) and thermal programmed desorption (TPD). Acetaldehyde desorbs molecularly from TiO 2(1 1 0) with minor decomposition channels yielding butene on the reduced TiO 2 surface and acetate on the oxidized TiO 2 surface. Acetaldehyde adsorbed on oxidized TiO 2(1 1 0) undergoes a facile thermal reaction to form a photoactive acetaldehyde–oxygen complex. UV irradiation of the acetaldehyde–oxygen complex initiated photofragmentation of the complex resulting in the ejection of methyl radical into gas phase and conversion of the surface bound fragment to formate.