甲醛在二氧化钛表面吸附及解离的第一性原理研究

We investigate the decomposition of toxic formaldehyde (HCHO) molecule on stoichiometric TiO2 rutile (110) surface using first principles calculations based on density functional theory (DFT). Adsorption configurations of HCHO on rutile (110) surface are conformed, among which the bidentate adsorption structure is the most stable one by forming O-Ti5c and C-Ob bonds, following by monodentate adsorption configurations by forming O-Ti5c and a hydrogen bond. We search reaction paths for adsorbed HCHO decomposing to CO catalyzed by TiO2 using nudged elastic band (NEB) method. An energy barrier of 2.37 eV is found for this bidentate adsorption configuration while for monodentate adsorption configuration only 1.2 eV is needed to overcome the barrier. These findings reveal the reaction mechanism of HCHO dissociation to CO on rutile (1 1 0) surface, and enrich the knowledge of organic reaction of small molecules catalyzed by metal oxides.