【摘要】 采用长链聚合物聚二烯丙基二甲基氯化铵(PDDA)对多壁碳纳米管(MWCNTs)进行修饰,并将采用胶体法还原出的铂(Pt)纳米粒子通过静电作用担载于PDDA修饰的多壁碳纳米管上,从而制备出Pt/PDDA/MWCNTs复合电催化剂.透射电镜(TEM)与X射线衍射(XRD)测试结果表明,Pt纳米粒子均匀地分布在MWCNTs的表面,其平均粒径约为3.6 nm.热失重分析显示催化剂的实际负载量为36%(w).旋转圆盘电极测试结果表明,Pt/PDDA/MWCNTs催化剂对碱性条件下的氧气还原反应(ORR)具有优异的催化活性.与负载量为40%(w)的商业Pt/C催化剂相比,Pt/PDDA/MWCNTs催化剂的氧气还原反应的起始电位和半波电位均正移约30 m V,其质量比活性更大.动力学研究结果进一步证实Pt/PDDA/MWCNTs催化剂比负载量为40%(w)的商业Pt/C催化剂在碱性条件下对氧气还原反应具有更优异的催化活性.更多还原

【Abstract】 Multi-walled carbon nanotubes(MWCNTs) were modified with the long-chain polymer poly(diallyldimethylammonium chloride)(PDDA) and used as support for Pt nanoparticles(NPs). Pt/PDDA/MWCNTs electrocatalysts were prepared by electrostatic adsorption of Pt NPs on the PDDA/MWCNTs support. Transmission electron microscopy(TEM) and X-ray diffraction(XRD) characterization revealed that the Pt NPs were well dispersed on the PDDA/MWCNTs support, with an average diameter of ~3.6 nm.Thermo gravimetric analysis showed that the loading of Pt was 36%(w). Rotating disk electrode(RDE)measurements showed that the Pt/PDDA/MWCNTs catalyst had excellent electrocatalytic activity for oxygen reduction in alkaline medium. Compared with commercial Pt/C(40%(w)), the Pt/PDDA/MWCNTs catalyst exhibited a positive shift of 30 m V for the oxygen reduction onset and half-wave potential. Kinetics study further confirmed the significantly enhanced oxygen reduction activity of the Pt/PDDA/MWCNTs catalyst in the alkaline medium.更多还原