负载型纳米TiO_2光催化氧化NO_x的实验研究

Experimental Study of Photocatalytic Oxidation for No_x Using Supported Nanometer TiO_2

阐述了负载型纳米TiO2光催化氧化NOx的机理,并设计了光催化氧化实验装置。采用超声波震荡将纳米TiO2均匀地镀在活性炭纤维、γ-Al2O3颗粒和石英砂颗粒上,制备了3种催化剂,从吸附、光解和氧化3个角度比较了3种催化剂的催化效果,然后考察了NO浓度、O2含量和含湿量等3个影响因素对NO转化率的影响。研究结果表明:NO浓度较低时,以活性炭纤维为载体的光催化剂,由于其较高的吸附能力和选择性催化氧化(SCO)特性,取得了较好的NO转化率;NO浓度较高时,以石英砂颗粒为载体的光催化剂,由于其较好的透光性,取得较好的NO转化率。

An efficient experimental device was designed based on the mechanism of photocatalytic oxidation for Nox using supported nanometer TiO2.Three kinds of catalysts were prepared with nanometer TiO2 uniformly coated on carbon fiber,γ-Al2O3 particles and quartz sand particles by ultrasonic wave.The catalytic effects of the catalysts were compared in terms of adsorption,photolysis and oxidation.Then the influences of NO initial concentration,O2 concentration and humidity on NO conversion rate were examined.The results showed that when NO concentration was low,the photocatalyst supported by the activated carbon fiber could help to achieve the ideal rate of NO conversion,due to its good adsorption and selective catalytic oxidation（SCO）;when NO concentration was relatively high,the photocatalyst supported by the quartz sand particles could help to obtain the ideal rate of NO conversion,due to its super optical transparency.