Au/γ-Al_2O_3催化剂的制备及其对气相三苯系污染物的催化消除  

Catalytic elimination of benzene series compounds over Au/γ-Al_2O_3 catalysts prepared by deposition-precipitation

作　　者：邓谦[1] 李辛玉[1] 蒋耀辉[1] 彭振山[1] 龙云飞[1] 韦宗元[1] 蔡铁军[1] 

机构地区：[1]湖南科技大学化学化工学院,湘潭411201

出　　处：《环境科学学报》2008年第11期2175-2180,共6页Acta Scientiae Circumstantiae

基　　金：湖南省教育厅重点科学研究项目(No.06A015);湖南省有机重点学科~~

摘　　要：采用沉积-沉淀法制备了负载型Au/γ-Al2O3催化剂,对模拟污染气体的三苯系(苯,甲苯,二甲苯)蒸气进行催化消除反应,探讨了金含量、活化条件对催化剂活性的影响.结果表明,负载型Au/γ-Al2O3催化剂用量为0.50g、反应气流速为20mL·min-1时,295℃下可完全催化消除浓度为7.57g.m-3的苯;在252℃下可完全催化消除浓度为7.49g.m-3的甲苯;在235℃下能完全催化消除浓度为3.07g.m-3的二甲苯.苯、甲苯和二甲苯最后都完全矿化为CO2和H2O,没有生成新的有机物.对催化反应进行了动力学研究,上述催化反应都是准一级反应.测定得到苯、甲苯和二甲苯催化反应的总包反应表观活化能分别为118.47kJ·mol-1、101.43kJ·mol-1和85.18kJ·mol-1.Supported Au/γ-Al2O3 catalysts were prepared by deposition-precipitation for the catalytic elimination of the benzene series（benzene,toluene,dimethylbenzene）.The effects of gold loadings,activation temperature and activation time on the activity of the catalysts were investigated.Complete conversion of 7.57g·m^-3 benzene was achieved at 295℃, of 7.49 g·m^-3 toluene at 252℃, and of 3.07 g·m^-3 dimethylbenzene at 235℃ over 0.5 g of catalyst when the flow rate of the feed gas was 20 mL·min^-1.The conversion of toluene remained at 100% after reacting for 45 hours over the Au/γ-Al2O3 catalyst.Benzene,toluene and dimethylbenzene were complete mineralized into CO2 and H2O,without side-products.The reaction kinetics of elimination of the three benzene series compounds over the supported Au/γ-Al2O3 catalysts were determined.The results showed that the catalytic eliminations of benzene,toluene and dimethylbenzene were all quasi-first order reactions,and the apparent activation energies were 118.47 kJ·mol^-1,101.43 kJ·mol^-1 and 85.18 kJ·mol^-1,respectively.

关 键 词：AU Γ-AL2O3 催化消除 三苯系 

分 类 号：X511[环境科学与工程—环境工程]