【作者】 耿晓云；

【导师】 任宝山；

【作者基本信息】 河北工业大学 ， 化工工艺， 2006， 硕士

【摘要】 随着大量装修材料和日用化工产品的使用,室内空气污染问题日益突出,苯就是其中一种常见的挥发性有机物。针对目前国内外单纯采用TiO₂光催化氧化法处理苯的效率不高的现状,本论文将TiO₂负载在吸附性载体上制成复合型催化剂,由于载体具有比较好的吸附性能,使负载催化剂表面上反应物分子浓度增大,可以提高对气相中苯的光催化降解活性。本文的主要研究结论如下: （1）制备了以活性炭、沸石、膨润土、和硅藻土载体的TiO₂催化剂,研究它们对空气中苯的光催化降解性能,并与无负载的TiO₂进行了比较。结果表明,选用吸附性的载体可以起到吸附与催化氧化的协同作用,提高催化效率。在以上几种催化剂中,TiO₂/活性炭对苯的去除效果最好,其次是TiO₂/沸石、TiO₂/膨润土和TiO₂/硅藻土。 （2）虽然TiO₂/活性炭对苯的净化能力最大,但是由于其吸附能力太强会影响反应物分子从吸附剂向催化剂的转移,而且使苯和降解过程中产生的中间产物不易解吸,因此多次使用后,催化活性下降很快。相比较而言,沸石的吸附能力适中,以其为载体的催化剂对苯也有较好的去除能力,因此本论文选用沸石作为载体做进一步的研究。实验表明:当二氧化钛的负载量为50%,焙烧温度为200℃,pH值为3时,制备的TiO₂/沸石催化剂光催化性能最好。而且催化性能比较稳定,连续使用五次对苯的去除率仍可以达到81%。 （3）苯的光催化反应符合一级动力学模型。在TiO₂/沸石作用下,苯的气相光催化反应的表观速率常数是无载体TiO₂的近3倍,表明载体的吸附作用对光催化性能的提高有着重要的影响。更多还原

【Abstract】 As the wide application of indoor decoration materials and chemical commodities ,the problem of indoor air pollution has become more and more serious.benzene is a commonly detected volatile organic compounds （VOCs） in the door. In view of that the photocatalytic degradation efficiencies of benzene only by TiO₂ is low,this paper prepared TiC>2 supported on sorbents. the supported catalysts on sorbents have better adsorptivity, so the activity in gas-phase photocatalytic reaction of benzene is higher than that of unsupported TiO₂.The main conclusions are as below:（1） The TiO₂ -loaded adsorbents such as activated carbon, zeolite, bentonite ,diatomite were prepared .and the photocatalytic degradation of benzene in gas phase was studied.then the efficiency of photocatalytic was compared with that of naked TiO₂. The experiment results indicated that the suitable adsorbent supports make a high concentration environment of organic substances of target around the loaded TiO₂ by adsorption , and then the rate of photooxidation is enhanced. It could be inferred from the comparison that TiO₂/actived carbon have the most powerful purification ability,in turn is TiO₂/ zeolite、 TiO₂/ bentonite and TiO₂/ diatomite.（2） Though the TiO₂/actived carbon have the most powerful purification ability,the adsorbents have so high adsorbabilities that the diffusion of adsorbed substances were hindered.and it also affected the adsorption of intermediate reaction product? The catalytic efficiency decreased quickly after used over several times. So this paper selected zeolite as supports which have moderate adsorblity.It was showed that when the TiO₂ content was 50%, the pH was kept around 3.0 , TiO₂ behaved a much higher activity after being sinterd at 200°C for 2 hours.And the catalytic activity is comparative steady.A processing rate of 81% still could beobtained.（3） The rate of photocatalytic degradation of benzene can be expressed in first-order kinetics model. By the TiCVzeolite The apparent rate constant of reaction is almost three times than that by naked TiC>2. It showed that the adsorbent play a important role in the inhancement of the catalytic efficiency.更多还原