微秒级原位时间分辨反射光谱法：水溶液中多晶铂微电极上吸附一氧化碳的氧化

In situ, time-resolved reflectance spectroscopy in the microsecond domain: oxidation of adsorbed carbon monoxide on polycrystalline pt microelectrodes in aqueous solutions.

作者信息

Shi Ping, Fromondi Iosif, Scherson Daniel A

机构信息

Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106-7078, USA.

出版信息

Langmuir. 2006 Dec 5;22(25):10389-98. doi: 10.1021/la061497e.

DOI:10.1021/la061497e

PMID:17129007

Abstract

The dynamics of the electrooxidation of adsorbed CO, COads, on polycrystalline Pt microelectrodes has been examined in CO-saturated 0.5 M H2SO4 and 0.5 M HClO4 aqueous solutions, using in situ, time-resolved, normalized differential reflectance spectroscopy lambda = 633 nm). Attention was focused on the unique dependence of COads oxidation on the potential at which the adsorbed full CO monolayer is assembled (i.e., hydrogen adsorption/desorption vs the double-layer region) using both fast linear scan voltammetry and potential step techniques. As evidenced from the data collected, COads oxidation at a fixed potential proceeds at slower rates when the monolayer is formed in the double- layer region compared to when it is formed in the hydrogen adsorption/desorption region. Possible explanations for this effect are discussed.

摘要

采用原位、时间分辨、归一化差分反射光谱法（波长λ = 633 nm），在CO饱和的0.5 M硫酸水溶液和0.5 M高氯酸水溶液中，研究了多晶铂微电极上吸附态CO（COads）的电氧化动力学。使用快速线性扫描伏安法和电位阶跃技术，重点关注了COads氧化对吸附完整CO单层时的电位（即氢吸附/脱附与双层区域）的独特依赖性。从收集到的数据可以看出，与在氢吸附/脱附区域形成单层相比，当单层在双层区域形成时，在固定电位下COads的氧化速率较慢。讨论了这种效应的可能解释。