Pt纳米催化剂的制备及其对二氯苯催化性能研究

Preparation and Catalytic Performances of Platinum Catalysts for Dichlorobenzene Hydrogenation

通过化学还原法和微波加热还原法分别制备了PVP保护的Pt胶体(PVP-Pt)和活性炭负载铂催化剂(Pt/C),用于催化邻二氯苯(o-DCB)加氢脱氯反应。常温常压下反应10h,两种催化剂对二氯苯的转化率都可达到99%以上,实现了对二氯苯的高效降解,建立了一种降解二氯苯的环保高效的方法。Pt/C催化二氯苯氢化反应中,乙醇作为溶剂时催化活性最好;NaOH的加入会抑制反应的进行;二氯苯催化氢化先生成中间产物氯苯和苯,二者进一步加氢生成环己烷。PVP-Pt催化二氯苯氢化反应中,Mg^(2+)可以提高催化活性,Fe^(3+)会使催化剂中毒;反应满足一级动力学方程。

The poly（N-vinyl-2-pyrrolidone）-stabilized platinum colloids（PVP-Pt）were prepared with chemical reduction method in methanol solvents.The Pt/C catalyst was prepared by microwave method in ethanediol solvents.Then dehydrogenation of dichlorobenzene（oDCB）was carried out in a batch mode using hydrogen over PVP-Pt and Pt/C at 298 Kand atmospheric pressure.Nearly 100%conversion of DCB could be obtained after 10 h.The results showed that Pt/C catalyst had the highest catalytic activity in the ethanol solvents.NaOH had inhibitory effect on the dehydrogenation of dichlorobenzene over Pt/C catalyst.The hydrogenation products consist of chlorobenzene,benzene and cyclohexane in the beginning,and finally only cyclohexane over Pt/C catalyst.The most favorable influence on the activity was obtained when Mg^（2＋） was used as modifier.The hydrodechlorination of dichlorobenzene took place in a first-order reaction over PVP-Pt.