Electrochemical Oscillations during Reduction of Nitrate and Nitrite Ions at High Overpotential

过电位 硝酸盐 振荡(细胞信号) 电化学 化学 电解 无机化学 亚硝酸盐 离子 催化作用 化学物理 电极 物理化学 有机化学 电解质 生物化学
作者
Terumasa Kuge,Yuri Yamada,Shuji Nakanishi,Yoshiharu Mukouyama
出处
期刊:Meeting abstracts 卷期号:MA2015-02 (47): 1877-1877
标识
DOI:10.1149/ma2015-02/47/1877
摘要

INTRODUCTION The electrochemical reduction of nitrate ions, NO 3 - , has been extensively studied concerning the mechanism of the nitrate reduction, the influence of electrolysis conditions, and the applications of the nitrate reduction, etc. [1, 2]. The studies have revealed that Cu is a catalyst for the electrochemical reduction [2]. Moreover, the nitrate reduction on Cu in acidic solutions was found to exhibit two types of electrochemical oscillations when it was accompanied by the hydrogen evolution reaction (HER) [3]. The oscillations appeared both under potential controlled conditions and under current controlled conditions. One of the oscillations, named oscillation I, appeared at a higher potential or a lower current (in absolute value) region where hydrogen bubbles due to the HER evolved slightly. Another oscillation, named oscillation II, appeared at a lower potential or a higher current region where hydrogen bubbles evolved vigorously (see Figs. 1a and 1b). An N-shaped negative differential resistance (N-NDR) plays an important role in most of the electrochemical oscillations, because an N-NDR characteristic causes a positive feedback mechanism. It was reported that the NO 3 - reduction was suppressed by adsorbed hydrogen atoms on a Cu surface, i.e., by reaction intermediates for the HER. Therefore, the N-NDR that caused oscillation I was ascribed to the suppression of the NO 3 - reduction, and the mechanism of oscillation I could be explained by the N-NDR [3]. On the other hand, the mechanism of oscillation II was unclear because the factor causing an N-NDR characteristic for oscillation II was not detected. Then, we have been investigating oscillation II, which yielded the following novel findings. Oscillation II also appeared during the nitrate reduction in non-acidic solutions (see Figs. 1c and 1d) [4]. Recently, oscillation II was found to appear during the nitrite ions, NO 2 - (see Figs. 1e and 1f). The hydrogen bubbles evolved synchronously with oscillation II [4]. In this presentation, the mechanism of oscillation II will be discussed on the basis of the findings. RESULTS and DISCUSSION Figure 1 shows the current ( I ) – potential ( E ) curves for a Cu-wire electrode. When the solution was 0.1 M H 2 SO 2 + 0.1 M KNO 3 (Figs. 1a and 1b), the NO 3 - reduction occurred in the potential region below ca. 0.2 V, and the reduction of water occurred in the potential region below ca. -1.5 V. Oscillations I appeared as a current oscillation at around -0.6 V and as a potential oscillation in the potential range between -0.4 and -0.7 V, that is, it was accompanied by the HER due to the H + reduction. On the other hand, oscillation II appeared as a current oscillation in the potential region below ca. -1.7 V and as a potential oscillation which ranged lower than -1.8 V, that is, it was accompanied by the HER due to the water reduction. These results lead to the idea that oscillation I appeared when the local pH at the electrode surface was acidic whereas oscillation II did when it was basic. When the solution was non-acidic, e.g., 0.2 M KNO 3 (Figs 1c and 1d) and 0.2 M NaOH + 0.2 M KNO 3 (data not shown), oscillation I did not appear whereas oscillation II appeared accompanied by the HER due to the water reduction [4], which supported the above idea. Furthermore, an oscillation, which was thought to be oscillation II because it synchronized with the behavior of the hydrogen bubble evolution, appeared when the solution was 0.2 M NaNO 2 (Figs. 1e and 1f). This indicates that the appearance of oscillation II was independent of the kind of reactive species. Thus, it can be concluded that the bubble evolution probably played an essential role in the appearance of oscillation II. REFERENCES [1] C. Milhano and D. Pletcher, in Modern Aspects of Electrochsmistry 45, R. E. White, Editor, p. 1, Springer, New York (2009). [2] V. Rosca, M. Duca, M. T. de Groot and M. T. M. Koper, Chem. Rev. 109, 2209 (2009). [3] Y. Mukouyama, S. Yamamoto, R. Nakazato, S. Nakanishi and H. Okamoto, ECS Trans. , 50 (48) 61-70, (2013). [4] Y. Mukouyama, S. Yamamoto, S. Nakanishi and H. Okamoto, ECS Trans. , 58 (25) 85-97, (2014). FIGURE CAPTION Figure 1. The I – E curves for (a, b) 0.1 M H 2 SO 4 + 0.1 M KNO 3 , (c, d) 0.2 M KNO 3 , and (e, f) 0.2 M NaNO 2 , measured (left) under potential controlled conditions and (right) under current controlled conditions. Figure 1

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
刚刚
SYLH应助Ridley采纳,获得10
1秒前
2秒前
咪花嗦完成签到,获得积分10
2秒前
Yimmy发布了新的文献求助10
2秒前
小马发布了新的文献求助10
2秒前
黄耀完成签到,获得积分10
2秒前
点墨完成签到 ,获得积分10
3秒前
小马甲应助7九采纳,获得10
3秒前
孙伟泰关注了科研通微信公众号
4秒前
伶俐如冰完成签到,获得积分10
4秒前
4秒前
SYLH应助gugu采纳,获得10
5秒前
新八完成签到,获得积分10
5秒前
yydragen应助老实的抽屉采纳,获得10
5秒前
5秒前
小红发布了新的文献求助10
6秒前
6秒前
6秒前
6秒前
无奈行恶完成签到,获得积分10
6秒前
机灵鸡发布了新的文献求助10
6秒前
Jasper应助科研通管家采纳,获得10
7秒前
汉堡包应助科研通管家采纳,获得10
7秒前
科目三应助科研通管家采纳,获得10
7秒前
酷波er应助科研通管家采纳,获得10
7秒前
7秒前
赘婿应助科研通管家采纳,获得10
7秒前
在水一方应助科研通管家采纳,获得10
7秒前
小二郎应助Laospakalfski采纳,获得10
7秒前
科研通AI2S应助科研通管家采纳,获得10
7秒前
Owen应助科研通管家采纳,获得10
7秒前
Valiant完成签到,获得积分10
7秒前
852应助科研通管家采纳,获得10
8秒前
上官若男应助科研通管家采纳,获得10
8秒前
星辰大海应助科研通管家采纳,获得10
8秒前
8秒前
搜集达人应助科研通管家采纳,获得30
8秒前
zzzz应助科研通管家采纳,获得10
8秒前
中和皇极应助科研通管家采纳,获得20
8秒前
高分求助中
【提示信息,请勿应助】关于scihub 10000
The Mother of All Tableaux: Order, Equivalence, and Geometry in the Large-scale Structure of Optimality Theory 3000
Social Research Methods (4th Edition) by Maggie Walter (2019) 2390
A new approach to the extrapolation of accelerated life test data 1000
北师大毕业论文 基于可调谐半导体激光吸收光谱技术泄漏气体检测系统的研究 390
Phylogenetic study of the order Polydesmida (Myriapoda: Diplopoda) 370
Robot-supported joining of reinforcement textiles with one-sided sewing heads 360
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 4009905
求助须知:如何正确求助?哪些是违规求助? 3549896
关于积分的说明 11304149
捐赠科研通 3284441
什么是DOI,文献DOI怎么找? 1810658
邀请新用户注册赠送积分活动 886424
科研通“疑难数据库(出版商)”最低求助积分说明 811406