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电化学(中英文) ›› 2018, Vol. 24 ›› Issue (3): 270-278.  doi: 10.13208/j.electrochem.170707

• 研究论文 • 上一篇    下一篇

铅修饰的纳米多孔铂催化剂对甲酸氧化的电活性

张媛媛,易清风*,左葛琨琨,邹涛,刘小平,周秀林   

  1. 湖南科技大学化学化工学院,湖南 湘潭,411201
  • 收稿日期:2017-07-07 修回日期:2017-12-26 出版日期:2018-06-28 发布日期:2018-01-08
  • 通讯作者: 易清风 E-mail:yqfyy2001@hnust.edu.cn
  • 基金资助:
    国家自然科学基金项目(21376070)

Lead Modified Nanoporous Platinum Electro-Catalysts for Formic Acid Oxidation

Yuanyuan Zhang, Qingfeng Yi*,Gekunkun Zuo, Tao Zou, Xiaoping Liu, Xiulin Zhou   

  1. School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China
  • Received:2017-07-07 Revised:2017-12-26 Published:2018-06-28 Online:2018-01-08
  • Contact: YI Qing-feng E-mail:yqfyy2001@hnust.edu.cn
  • Supported by:
    National Natural Science Foundation of China(21376070)

摘要:

用合适金属修饰的铂催化剂能够显著增强其对甲酸氧化的电活性. 本文以水热法制备了钛负载的纳米多孔铂电极(nanoPt/Ti),然后采用循环伏安法,通过扫描不同的周数(n),用适量的铅对nanoPt/Ti电极进行修饰,得到一种新型的铅修饰的纳米多孔铂电极(nanoPb(n)-Pt/Ti). 采用循环伏安(CV)、计时电流和计时电位法研究其对对甲酸氧化的电活性. CV结果显示nanoPt/Ti和nanoPb(n)-Pt/Ti电极对甲酸氧化表现出较高的催化活性,并且nanoPb(20)-Pt/Ti电极对甲酸氧化的起始电位为-0.06 V,相比nanoPt/Ti电极的起始电位(0.06 V),明显有所负移. 此外,nanoPb(20)-Pt/Ti电极的第一个氧化峰电流密度为12.7 mA·cm-2,远远大于nanoPt电极(4.4 mA·cm-2);计时电流显示在电位为0.1 V时,在0.5 mol·L-1 H2SO4 + 1 mol·L-1 HCOOH溶液中,nanoPb(20)-Pt/Ti电极达到稳定时的电流为8.09 mA·cm-2,是nanoPt电极的60倍,表明铅修饰的nanoPt/Ti对甲酸氧化的电活性急剧增加;在1.5 mA、2 mA、2.2 mA和2.5 mA下的计时电位结果表明,nanoPb(20)-Pt/Ti电极上甲酸氧化过程表现出显著的电化学振荡,且和nanoPt/Ti电极相比,振荡现象能持续更长的时间,说明nanoPb(20)-Pt/Ti电极具有更强的表面抗毒化能力.

关键词: 甲酸氧化;纳米多孔Pt, 纳米多孔Pb-Pt;电化学震荡

Abstract:

Platinum (Pt) catalysts modified by other suitable metals significantly enhance their electrochemical activities for formic acid oxidation. In this work, a titanium-supported nanoporous network platinum (nanoPt/Ti) electrode was prepared using a hydrothermal method. The as-prepared nanoPt/Ti electrode was modified with a certain amount of lead by using cyclic voltammetry for different scan cycle numbers (n), namely, n = 10, 15, 20 and 30, to synthesize the novel lead-modified nanoporous Pt (nanoPb(n)-Pt/Ti) electrodes. Electro-oxidation of formic acid on these electrodes was studied with cyclic voltammetry (CV), chronoamperometry and chronopotentiometry in sulfuric acid solution. CV curves showed that both nanoPt/Ti and nanoPb(n)-Pt/Ti electrodes displayed high electrocatalytic activities for formic acid oxidation, and the onset potential of formic acid oxidation on the nanoPb(20)-Pt/Ti electrode was -0.06 V, which was more negative than that on the nanoPt/Ti electrode (0.06 V). In addition, the first oxidation peak current density on the nanoPb(20)-Pt/Ti electrode was 12.7 mA·cm-2, which was far larger than that on the nanoPt electrode (4.4 mA·cm-2). Chronoamperommetric data at 0.1 V in 0.5 mol·L-1 H2SO4 + 1 mol·L-1 HCOOH suggested that the nanoPb(20)-Pt/Ti electrode exhibited the stable current density of 8.09 mA·cm-2 which was 60 times higher than the nanoPt electrode, indicating the dramatic enhancement of electroactivity on the lead-modified nanoPt/Ti electrode for formic acid oxidation with comparison to the nanoPt/Ti electrode. Chronopotentiometric responses on the electrode at 1.5 mA, 2 mA, 2.2 mA and 2.5 mA in 0.5 mol·L-1 H2SO4 + 1 mol·L-1 HCOOH revealed notable electrochemical oscillations which lasted longer time than those on the nanoPt/Ti electrode. It was demonstrated that the lead-modified nanoPb(20)-Pt/Ti electrode presented the most significant enhancement on surface anti-poisoning ability.

Key words: formic acid oxidation, nanoporous Pt, nanoporous Pb-Pt, electrochemical oscillations

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