碳纳米管载PtPb、PtBi纳米催化剂对甲酸抗CO中毒的研究

Prepared PtPb,PtBi nano-catalyst With Template of Carbon Nanotubes and Studied on CO-poisoning for Formic Acid

混酸法预处理了载体碳纳米管(CNTs),采用两步法制备PtPb/CNTs和PtB i/CNTs催化剂。以甲酸为研究对象,首次采用循环伏安法长时间连续性扫描的方法研究催化剂的抗CO中毒能力。研究发现,添加了Pb、B i金属后,增强了Pt/CNTs催化剂性能,如甲酸的起始氧化电位明显降低、氧化电流密度增大且抗毒性能增强。PtPb/CNTs、PtB i/CNTs催化甲酸的起始氧化电位都低于Pt/CNTs(0.099V),依次为-0.108和-0.004V(Vs.Ag/AgC l);在0.6V处,PtPb/CNTs、PtB i/CNTs催化氧化甲酸产生的电流密度都明显大于Pt/CNTs(0.79 mA/cm2),依次为3.10和1.77mA/cm2;PtPb/CNTs、PtB i/CNTs催化剂的寿命依次为Pt/CNTs催化剂的4倍和5倍。本文主要进行燃料电池电催化剂材料的研究,对于制造新型电催化剂有一定的探索作用。

The carbon nanotubes （CNTs） were treated with a mixed acid of sulfuric acid ＆ nitric acid. Then,we prepared PtPb/CNTs,PtPb/CNTs nano - catalysts by a hydrothermal method with two steps. The catalysts were characterized by cyclic voltammetry and formic acid was studied. The results indicated that the addition of cheap Pb 、 Bi metal inhibited the poisoning of the Pt catalysts by the COads intermediate, and improved the properties of the catalysts. We obtained lower onset oxidation potential and higher electrocatalytic activity for the oxidation of formic acid. The PtPb/CNTs catalyst and PtBi/CNTs catalyst showed low onset potential, enhanced electrocatalytic activity and long lifetime for formic acid electro- oxidation compared with that on Pt/CNTs catalyst. The nset potential for formic acid oxidation was -0. 108 V on PtPb/ CNTs catalyst and - 0.004V （vs. Ag/AgCl） on PtBi/CNTs catalyst but 0.099V （ vs. Ag/AgCl） on Pt/CNTs catalyst. At 0.6V, the peak current density of formic acid oxidation on PtPb/CNTs catalyst was 3. 1mA/cm2 and on PtBi/CNTs catalyst was 1.77mA/cm2, compared with that on Pt/CNTs catalyst was 0.79mA/cm2. The lifetime of PtPb/CNTs catalyst and Pt- Bi/CNTs catalyst were 4 times and 5 times than that of Pt/CNTs catalyst. In this paper, the research of catalyst materials for fuel cell is certain of the manufacture of new electrical exploration.