Ru/ZSM-5载体效应及Ru活性物种对邻二氯苯氧化降解研究

Effects of support and Ru active species on oxidative degradation of o-dichlorobenzene over Ru/ZSM-5

为了研究载体效应及不同Ru物种催化氧化氯代芳烃活性,制备不同载体(Al_(2)O_(3),HY,SiO_(2)和ZSM-5)及不同Ru物种(即Ru^(0),Ru^(3+),Ru^(4+))催化剂用于邻二氯苯(氯代芳烃模型化合物)的催化氧化。结果表明:相比于其他载体,ZSM-5负载型催化剂表现出良好的催化活性;通过热处理控制制备不同Ru物种催化剂(Ru/ZSM-5,Ru/ZSM-5(100)及Ru/ZSM-5(300)),其中Ru/ZSM-5表现出最高的邻二氯苯转化率(97.8%)及CO_(2)收率(54.5%)。稳定性实验研究表明Ru/ZSM-5催化剂能够稳定运行600 min仍保持较高催化活性及矿化能力。通过NH3-TPD的研究可知:载体ZSM-5中较多的酸性位点有助于邻二氯苯吸附,进而促进其催化氧化;XPS表征结果发现Ru^(0)含量对其催化活性具有显著的影响,Ru/ZSM-5的Ru^(0)含量最高,因而具有高效的邻二氯苯催化氧化性能。

To investigate the effect of support and Ru active species on the catalytic oxidation of polychlorinated aromat⁃ic hydrocarbons(PCAHs),catalysts with different supports(Al_(2)O_(3),HY,SiO_(2)and ZSM-5)and different Ru species(Ru^(0),Ru^(3+),Ru^(4+))were prepared for catalytic oxidation of o-dichlorobenzene(a PCAHs model compound).The results showed that compared with other supports,ZSM-5 supported catalysts exhibited good catalytic activity;meanwhile,the catalysts with different Ru species(Ru/ZSM-5,Ru/ZSM-5(100)and Ru/ZSM-5(300))were prepared by controlled heat treatment,and Ru/ZSM-5 demonstrated the highest catalytic conversion of o-dichlorobenzene(97.8%)and CO_(2)yield(54.5%).Ru/ZSM-5 also maintained good catalytic stability with high oxidation activity and mineralization ability for 600 min.NH3-TPD study provided that the abundant acid sites in ZSM-5 contributed to the adsorption of o-dichlorobenzene,thus pro⁃moting its catalytic oxidation.XPS characterization showed that the content of Ru0 demonstrated significant effect on the catalytic activity.Ru/ZSM-5 possessed the highest content of Ru0,and hence it exhibited the highest catalytic oxidation performance in o-dichlorobenzene oxidation.