CNT表面修饰对Pt/CNT在邻氯硝基苯加氢反应中催化性能的影响

用乙二醇还原法制备了碳纳米管(CNT)负载的铂催化剂(Pt/CNT).考察了CNT化学修饰与物理修饰对催化剂的影响.CNT化学修饰采用H2SO4-HNO3氧化法,物理修饰采用十二烷基硫酸钠(SDS)吸附法.用X射线衍射、透射电子显微镜、电感耦合等离子发射光谱、H2程序升温脱附、傅里叶变换红外光谱和元素分析对Pt/CNT催化剂进行了表征,并以邻氯硝基苯选择加氢为探针反应考察了Pt/CNT的催化性能.结果表明,化学修饰与物理修饰都能在CNT表面引入一定数量的活性位,有助于促进Pt异相成核,提高Pt的分散性,进而提高催化剂的活性.SDS在一定浓度下可形成特定结构的胶束,导致形成特定形貌的Pt纳米粒子.

Effect of CNT Surface Modification on Catalytic Performance of Pt/CNT for Selective Hydrogenation of o-Chloronitrobenzene

Pt/CNT (carbon nanotube) catalysts were prepared by the ethylene glycol reduction method through chemical modification and physical modification of CNT. The catalytic performance of the Pt/CNT for hydrogenation of o-chloronitrobenzene was tested. An acid mixture of H_2SO_4-HNO_3 was used for chemical modification and sodium dodecyl sulfate (SDS) was used for physical modification. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, inductively coupled plasma-atomic emission spectroscopy, H_2-temperature programmed desorption, Fourier transform infrared spectroscopy, and elemental analysis. Both chemical modification and physical modification of CNT can result in functional groups that are beneficial to the dispersion and the nucleation of Pt particles, leading to improved catalytic performance of the catalyst. In the case of SDS modification, SDS formed micellar structure first, in which the nucleation and growth of Pt particles took place, leading to the formation of Pt particles with controllable morphology.