Heterogeneous reaction of formaldehyde on the surface of TiO_2 particles  

作　　者：XU BingYe 1,2,ZHU Tong 1,TANG XiaoYan 1 & SHANG Jing 1 1 State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China 2 Zhejiang Province Environmental Monitoring Center,Hangzhou 310012,China 

出　　处：《Science China Chemistry》2010年第12期2644-2651,共8页中国科学（化学英文版）

基　　金：supported by the National Basic Research Program of China(2002CB410802)

摘　　要：The heterogeneous reaction of formaldehyde (HCHO) on the surface of titanium dioxide (TiO2) was investigated in situ using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) combined with ion chromatography (IC),X-ray diffraction (XRD),and transmission electron microscopy (TEM).Formate,dioxymethylene,methoxy,and polyoxymethylene were observed in the infrared spectra of TiO2 particles during the reaction.On the surface of TiO2,the adsorbed HCHO was first oxidized to dioxymethylene and further oxidized to formate.The effects of temperature and ultraviolet radiation (UV) on the reaction products and reactive uptake coefficients were studied,and the results indicate that the reaction rate can be accelerated at increasing temperatures as well as under UV.The heterogeneous reaction mechanisms of HCHO on the surface of TiO2 in the dark and under UV irradiation are proposed.Kinetic measurements show that formate formation on TiO2 is second order in HCHO concentration and the initial reactive uptake coefficients at room temperature calculated with the Brunauer-EmmettTeller specific surface area are (0.5-5) × 10-8 ([HCHO]:1 × 1013-2 × 10 14 molecules/cm3).A linear function relationship exists between the uptake coefficient and the concentration.The apparent activation energy of the reaction was also determined.The heterogeneous reaction of formaldehyde (HCHO) on the surface of titanium dioxide (TiO2) was investigated in situ using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) combined with ion chromatography (IC),X-ray diffraction (XRD),and transmission electron microscopy (TEM).Formate,dioxymethylene,methoxy,and polyoxymethylene were observed in the infrared spectra of TiO2 particles during the reaction.On the surface of TiO2,the adsorbed HCHO was first oxidized to dioxymethylene and further oxidized to formate.The effects of temperature and ultraviolet radiation (UV) on the reaction products and reactive uptake coefficients were studied,and the results indicate that the reaction rate can be accelerated at increasing temperatures as well as under UV.The heterogeneous reaction mechanisms of HCHO on the surface of TiO2 in the dark and under UV irradiation are proposed.Kinetic measurements show that formate formation on TiO2 is second order in HCHO concentration and the initial reactive uptake coefficients at room temperature calculated with the Brunauer-EmmettTeller specific surface area are (0.5-5) × 10-8 ([HCHO]:1 × 1013-2 × 10 14 molecules/cm3).A linear function relationship exists between the uptake coefficient and the concentration.The apparent activation energy of the reaction was also determined.

关 键 词：DRIFTS FORMALDEHYDE HETEROGENEOUS reaction REACTIVE UPTAKE COEFFICIENT TiO2 

分 类 号：O643.32[理学—物理化学]