物理化学学报 >> 1997, Vol. 13 >> Issue (08): 673-679.doi: 10.3866/PKU.WHXB19970801

研究论文    下一篇

铂单晶电极表面不可逆反应动力学II 铂单晶(100)晶面电极上甲酸氧化反应动力学参数解析

孙世刚,杨毅芸   

  1. 厦门大学固体表面物理化学国家重点实验室,化学系,厦门 361005
  • 收稿日期:1996-11-15 修回日期:1997-03-19 发布日期:1997-08-15
  • 通讯作者: 孙世刚

Kinetics of Irreversible Reactions on Platinum Single Crystal Electrodes II.Data Processing and Kinetics Parameters for HCOOH Oxidation on Pt(100) Electrode

Sun Shi-Gang,Yang Yi-Yun   

  1. State Key Laboratory for Physical Chemistry of the Solid Surface,Department of Chemistry,Institute of Physical Chemistry,Xiamen University,Xiamen 361005
  • Received:1996-11-15 Revised:1997-03-19 Published:1997-08-15
  • Contact: Sun Shi-Gang

摘要:

运用程序电位阶跃方法,避免甲酸解离吸附的干扰,成功地研究了Pt(100)单晶电极上甲酸经活性中间体直接氧化至CO2的反应动力学.提出对电化学暂态实验数据进行积分变换求解动力学参数的方法,编制了相关的计算机软件,首次获得甲酸在Pt(100)单晶电极上直接氧化的反应动力学参数. 结果给出在0.02V至0.15V电位区间,速率常数kf的对数随电极电位线性增长,kf从9.51×10-4上升到1.38×10-2cm•s-1.获得传递系数β=0.309,5×10-3mol•L-1 HCOOH+0.5mol•L-1 H2SO4溶液中甲酸的扩散系数D=1.80×10-5cm2•s-1.

关键词: Pt(100), 单晶电极, 甲酸氧化反应动力学, 数据解析

Abstract:

The kinetics of electrooxidation of HCOOH on Pt(100) via reactive intermediates was studied by using programmed potential step technique, which avoided successfully the interference of self-poisoning. A new data processing method was established based on the transform of integration of digital data recorded in electrochemical transient experiments, and the computer software developed for this method allowed us to obtain quantitatively, for the first time, the kinetics parameters of HCOOH oxidation on Pt(100) electrode. The results demonstrated that in a narrow potential range of 0.02 V to 0.15 V, the rate constant kf being varied from 9.510 × 10-4 to 1.38 ×10-2cm•s- 1 and the relationship between ln(kf) and E being a straight line. The transfer coefficient (β) was calculated at 0.309, and the diffusion coefficient (D) of HCOOH in 5×10-3mol•L- 1 HCOOH + 0. 5mol•L- 1 H2SO4 solution was evaluated at 1.80 × 10-5 cm2•s-1.

Key words: Pt(100) single crystal electrode, Oxidation of formic acid, Reaction kinetics;Data processing