Adsorbate and Electrode Reactions on Pt Single Crystal Electrode -What is the Real Reaction Intermediate? -

Pt 单晶电极上的吸附物和电极反应 - 什么是真正的反应中间体？

• 批准号: 05453116
• 负责人: KITA Hideaki
• 金额: $ 4.42万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05453116/
• 关键词: Pt single crystal electrode; Hydrogen electrode reaction; Electrochemical behavior of nitrogen oxides; Oxygen electrode reaction; Electrochemical oxidation of formic acid; Anion adsorption on electrode; Surface structure dependence of electrode reac

1. Hydrogen Electrode Reaction. The usually observed hydrogen atom on the electrode surface (Upd-H) cannot be the reaction intermediates for the hydrogen evolution reaction. The real reaction intermediate was the On-top H which is unstable.2. Nitrogen Oxide Reactions. Among a series of nitrogen oxides, No, NH_2OH and N_2H_4 are active in the electro-oxidation and/or -reduction on Au single crystal electrode. These reactions are structure-insensitive in contrast to the case on the Pt single crystal electrode. The reaction products are confirmed directly by the "One point touch" DEMS developed in our laboratory which is applicable to a small electrode of 3-5 mm in diameter.3. Oxygen Electrode Reaction. The oxygen reduction reaction appears sensitive on the surface atomic structure of the electrode but not in a direct manner ; i.e., the specific adsorption of anion is structure sensitive and affects the electrode reaction. In addition, it was found that the oxygen reduction reaction does … More not require so much reaction sites of the surface, being at most 0.03% of the total Upd-H sites.4. Oxidation of C_1 compounds. The formic acid oxidation shows the structure dependence and Pt (100) reveals the highest activity. The reaction proceeds via two routes ; one is predominant in a less positive potential region occurs with a small number of reaction sites, and the other is predominant in a more positive potential region. However, the reaction is almost completely suppressed at a highly positive potential region (>1.0V), indicating the formation of the retarding species on the surface.5. Role of Water Molecules. The above retarding phenomenon is observed on the other electrode reactions studied and must be attributed to a common factor. The present work concludes that the water molecule is now tightly bound on the surface in the highly potential region and prohibits the interaction of the reactant with the surface. This will be a key information to solve, for example, the high overpotential of the oxygen reduction on the most efficient electrocatalyst of Pt, which is used in the fuel cell. Less

1.氢电极反应通常在电极表面上观察到的氢原子（Upd-H）不可能是析氢反应的反应中间体。真实的反应中间体是不稳定的On-top H.氮氧化物反应。在一系列氮氧化物中，NO、NH_2OH和N_2H_4在Au单晶电极上的电氧化和/或还原中具有活性。这些反应是结构不敏感的情况下，在Pt单晶电极。反应产物直接用本实验室研制的适用于直径3-5 mm的小电极的“一点接触”DEMS确认.氧电极反应氧还原反应在电极的表面原子结构上表现出敏感性，但不是以直接的方式;即，阴离子的特异性吸附是结构敏感的，并影响电极反应。此外，发现氧还原反应确实 ...更多信息 不需要那么多的表面反应位点，至多为总Upd-H位点的0.03%。C_1化合物的氧化甲酸氧化反应表现出结构依赖性，Pt（100）的催化活性最高.该反应通过两条路线进行;一条路线在较少的正电势区域中占主导地位，反应位点的数量较少，另一条路线在更正的电势区域中占主导地位。然而，在高正电位区（>1.0V），反应几乎被完全抑制，表明表面上形成了阻滞物种。水分子的作用在所研究的其他电极反应中也观察到上述阻滞现象，这是一个共同的因素。本工作的结论是，水分子现在是紧密结合在表面上的高电位区，并禁止与表面的反应物的相互作用。这将是解决例如在燃料电池中使用的最有效的Pt电催化剂上的氧还原的高过电位的关键信息。少

项目成果

S.Ye: "Adsorbed HNO_2/NO redox couple at Pt(111) single crystal electrode" J.Electroanal.Chem.346. 1102-1106 (1993)

S.Ye：“Pt(111) 单晶电极上吸附的 HNO_2/NO 氧化还原对”J.Electroanal.Chem.346。

K.Shimazu: "Electrochemical quartz crystal microbalance studies on adsorbed species formed from formic acid at Pt electrodes" Chem.Lett.61. 788-789 (1993)

K.Shimazu：“对 Pt 电极上甲酸形成的吸附物质的电化学石英晶体微天平研究”Chem.Lett.61。

S.Suzuki, T.Nakato, H.Hattori and H.Kita: "Reduction of NO on Au single crystal electrodes in alkaline solution" J.Electroanal.Chem.(in press).

S.Suzuki、T.Nakato、H.Hattori 和 H.Kita：“碱性溶液中金单晶电极上 NO 的还原”J.Electroanal.Chem.（印刷中）。

H.Narumi, H.Kita and H.Murakami: "Theoretical analysis of the hydrogen waver on platinum single crystal electrodes" Chem.Lett.35-36 (1995)

H.Narumi、H.Kita 和 H.Murakami：“铂单晶电极上氢波动的理论分析”Chem.Lett.35-36 (1995)

H.: "Adsorbed species and electrode reactions. Effect of sulphate ion on hydrogen and methanol oxidation on reactions at Pt single crystal electrodes" DENKI KAGAKU. 61. 777-778 (1993)

H.：“吸附物质和电极反应。硫酸根离子对氢和甲醇氧化对 Pt 单晶电极反应的影响”DENKI KAGAKU。