TiO_2负载Pt对光催化去除低浓度NO性能的影响

Photocatalysis Activity of Pt/TiO_2 Toward Low Concentration NO Abatement

以溶胶-凝胶法以及湿式浸渍法制备了Pt/TiO2催化剂,采用了XRD、BET、UV-vis、TEM、XPS等方法进行表征,并进行了对NO的催化氧化性能测试.结果表明铂的负载能显著提高TiO2光催化剂对NO的氧化转化能力和去除率.0.5%Pt/TiO2对NO的氧化率与去除率分别为45.0%和38.1%,与纯锐钛矿TiO2(13.6%,10.7%)相比,氧化效率提高3.3倍,去除效率提高3.6倍.通过比较不同方法制备的负载Pt催化剂的活性,初步讨论了催化剂表面发生的反应机理:铂氧化物以及催化剂表面吸附的O2分子通过与光生电子和光生空穴结合,产生了强氧化性自由基,将NO氧化得到NO2.

Pt/TiO2 catalyst was prepared by sol-gel and wet impregnation method. By means of XRD, BET, UV- vis, TEM and XPS, the catalyst was characterized and NO photocatalytic performance test was evaluated. The re- sults showed that the Pt loading could significantly increase the catalytic activity toward NO oxidation and removal. The 0.5% Pt/TiO2 showed a NO oxidation rate of 45% and a removal efficiency of 38.1% , respectively, much higher of that of anatase TiO2（ 13.6% , 10.7% ）. Through the comparison of catalytic activities of Pt/TiO2 synthe- tized in different methods, reaction mechanism was preliminary discussed： Pt oxides and O： adsorbed on the cata- lyst surface had promoted the generation of strong oxidizing free radicals, with the reaction of photogenerated carri- ers, and then NO was oxy-genated into NO2 by the free radicals.