著者

大﨑 隆久 佐藤 祐一

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.83, no.1, pp.41-48, 2015-01-05 (Released:2015-01-05)

参考文献数

9

著者

彌田 智一 鎌田 香織

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.84, no.9, pp.715-720, 2016-09-05 (Released:2016-09-05)

参考文献数

9

被引用文献数

1 1

著者

Airi YAMAGUCHI Naoki SHIDA Mahito ATOBE Tomoko YAJIMA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.91, no.11, pp.112016, 2023-11-30 (Released:2023-11-30)

参考文献数

35

被引用文献数

1

---

Photocatalytic single-electron transfer (SET) reactions involving perfluoroalkyl halides play a crucial role in synthetic organic chemistry. However, the electrochemical data for these compounds, which are essential in the discussion of the SET process, are missing. In this study, the electrochemical reduction potentials of perfluoroalkyl halides, alkyl halides, and other analogous compounds were investigated in 0.1 M Bu4NPF6/CH3CN using Ag, Pt, and glassy carbon electrodes. The Ag electrode showed remarkable catalytic properties and a positive reduction peak shift during the reduction reaction; this indicates that the Ag electrode is suitable for estimating the electrochemical potential of the SET process. This study provides a comprehensive dataset for the electrochemical measurements of perfluoroalkyl and alkyl halides, which will help synthetic organic chemists select appropriate reaction systems for these compounds.

著者

Yanchang WANG Sangmin LEE Kentaro YAMAMOTO Toshiyuki MATSUNAGA Hidenori MIKI Hideki IBA Koichi TSUCHIYA Tomoki UCHIYAMA Toshiki WATANABE Tsuyoshi TAKAMI Yoshiharu UCHIMOTO

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.22-00133, (Released:2023-01-28)

著者

Naoya WADA Tomoaki KUMEDA Masashi NAKAMURA Nagahiro HOSHI

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.20-00043, (Released:2020-06-16)

参考文献数

27

被引用文献数

1

---

Previous study shows that tetra-n-hexylammonium cation (THA+), which is composed of one nitrogen atom and four alkyl chains, increases the activity of the oxygen reduction reaction (ORR) on Pt(111) eight times as high as that of bare Pt(111). We have studied the ORR on Pt single crystal electrodes modified with alkane to elucidate which part of THA+ contributes to the enhancement of the activity for the ORR. The ORR activity is increased only twice by the modification of Pt(111) with dodecane and hexadecane. Combination of a nitrogen atom and alkyl chains of THA+ plays an important role in enhancing the ORR on Pt electrodes. Dodecane and hexadecane increases the ORR activity on Pt(111) and Pt(110), but they deactivate the ORR on Pt(100) and the high index planes.

著者

Kazuhiro OKAMOTO Yasushi IMADA Naoki SHIDA Yoshikazu KITANO Mahito ATOBE Kazuhiro CHIBA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.91, no.11, pp.112006, 2023-11-28 (Released:2023-11-28)

参考文献数

21

被引用文献数

1

---

Herein, we report that the 2,7-dimethoxynaphthyl (2,7-DMN) group is a novel electroauxiliary that is readily installed at the N-α position of a carbamate through Friedel–Crafts-type arylation. The resulting N-α C–C bond is easily cleaved through low-potential electrochemical oxidation to give the corresponding iminium cation.

著者

Rumi IZUMIYA Mahito ATOBE Naoki SHIDA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.91, no.11, pp.112003, 2023-11-28 (Released:2023-11-28)

参考文献数

19

被引用文献数

1

---

β-Scission from alkoxy radical enables selective Csp3-Csp3 bond cleavage under ambient conditions, offering a useful method for organic synthesis. Various photocatalytic systems for β-scission have been reported, where proton-coupled electron transfer (PCET) mechanism plays a key role in the generation of alkoxy radical and thus β-scission. Electrochemical β-scission has been mainly pioneered in the presence of mediator, and a direct electrochemical system has rarely been investigated. Here, we investigated the β-scission via direct electrochemical oxidation using a model compound with β-O-4 linkage. Synthetic experiments suggested smooth progress of β-scission in the presence of collidine as a base. Cyclic voltammetry measurement, voltammetric simulation, and quantum simulation suggested the PCET mechanism is responsible for the electrochemical reaction, which is followed by β-scission process. This report provides fundamental insights into the electrochemical β-scission via direct electron transfer on the electrode, which contribute to future applications such as biomass valorization.

著者

Shohei YOSHINAGA Mahito ATOBE Naoki SHIDA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.91, no.11, pp.112002, 2023-11-28 (Released:2023-11-28)

参考文献数

14

---

Redox behavior is a fundamental and fascinating feature of polycyclic aromatic hydrocarbons (PAHs). Cyclic voltammetry (CV) measurements are commonly performed to estimate the electronic structure of PAHs and to determine the stability of their oxidation and reduction states. However, the influences of electrolytes on electrochemically oxidized/reduced PAHs have rarely been discussed. In this note, we report voltammetric analyses of five PAHs (anthracene, 9,10-dimethylanthracene, phenanthrene, pyrene, and perylene) in Bu4NB(C6F5)4/CH2Cl2 and Bu4NTfO/CH2Cl2, respectively, to highlight how the electrolyte-coordination affects the oxidative voltammetric behavior of PAHs. In most cases, reversible voltammetric responses were obtained with Bu4NB(C6F5)4/CH2Cl2, suggesting that this electrolyte is enough weakly coordinating to investigate its intrinsic oxidation behavior. On the other hand, irreversible voltammetric responses were obtained with Bu4NTfO/CH2Cl2, indicating that the presence of a relatively coordinating anion, TfO−, destabilizes the radical cation species and induces further chemical and electrochemical processes. This study provides hints for rational electrolyte design to properly understand the redox behavior of molecules and maximize the potential of functional molecules for applications related to redox chemistry.

著者

Yasuyuki OKUMURA Eisuke SATO Koichi MITSUDO Seiji SUGA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.91, no.11, pp.112007, 2023-11-28 (Released:2023-11-28)

参考文献数

34

---

The electrochemical synthesis of dibenzothiophene S,S-dioxides was achieved by the anodic oxidation of biaryl sulfonyl hydrazides. The use of Bu4NOTf as the electrolyte in HFIP/CH3NO2 (15 : 1) is essential. Several biaryl sulfonyl hydrazides followed by dibenzothiophene S,S-dioxides under mild electrochemical conditions. Control experiments and density functional theory calculations suggested that the electrooxidation of biaryl sulfonyl hydrazides would generate sulfonyl radicals or sulfonyl cations which were converted to dibenzothiophene S,S-dioxides.

著者

Eisuke SATO Sayaka OGITA Koichi MITSUDO Seiji SUGA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.91, no.11, pp.112005, 2023-11-28 (Released:2023-11-28)

参考文献数

26

---

Cathodic reduction efficiently cleaved N–O bonds. The simple cathodic reduction of Weinreb amides in a divided cell afforded the corresponding amide in good yields. Cyclic voltammetry experiments and density functional theory calculations suggested that the direct reduction of the N-methoxy amide generates the methoxy radical and amide anion. The release of methanol derived from methoxy radical would be the driving force of the N–O bond cleavage.

著者

Yoshimasa SUZUKI Minoru MIZUHATA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.90, no.10, pp.103001, 2022-07-11 (Released:2022-07-11)

参考文献数

40

被引用文献数

1 3

---

We have established a method for measuring the zeta potential generated at the interface between a nonaqueous electrolyte solution utilized in LiClO4/propylene carbonate (PC) electrolyte and lithium cobalt oxide (LiCoO2) by the streaming potential method. Since the surface potential of the metal oxide dispersed in the aprotic nonaqueous solvent contains only a very small amount of water-based potential-determining ions such as H+ and OH−, the potential is determined by the adsorption of the solvated electrolyte itself. Unlike aqueous systems with potential-determining ions that exhibit specific adsorption, it took a very long time until the equilibrium state of the ion distribution near the solid surface was reached and the potential stabilized, with a time constant that amounted to about 5 minutes. Therefore, a detailed analysis of the change over time of the potential after the pressure setting showed that the predictive potential showed a change over time with almost a single relaxation having certain time constant. The measurement time of the streaming potential was corresponded to about the time constant, and the resulting zeta potential showed an anomalous concentration dependence as a maximum around 1.0 mol L−1 PC and a minimum at 1.5 mol L−1 PC for the concentration of each solution.

著者

Athchaya SUWANSOONTORN Katsuhiro YAMAMOTO Shusaku NAGANO Jun MATSUI Yuki NAGAO

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.21-00042, (Released:2021-05-21)

参考文献数

47

被引用文献数

2

---

Investigation of interfacial proton transport is necessary to elucidate biological systems. As commonly found in biomaterials, the carboxylic acid group was proven to act as a proton-conducting group. This study investigated the influence of carboxylic acid concentration on both interfacial and internal proton transport. Several styrene-based polymers containing the carboxylic acid group were synthesized. The amount of carboxylic acid group in the polymer chain was varied to explore the effects of weak acid concentration on polymer thin films’ electrical properties. The IR p-polarized multiple-angle incidence resolution spectrometry (pMAIR) spectra show the higher ratio of the free carboxylic acid groups rather than cyclic dimers in polymers with a higher concentration of carboxylic acid group, facilitating the more hydrogen bonding networks in films. The water uptake results reveal the similar number of adsorbed water molecules per carboxylic acid group in all thin films. Remarkably, polymer thin films with high carboxylic acid concentration provide internal proton conduction because of the relative increase in the amount of the free carboxylic acid group. In contrast, interfacial proton conduction was found in low carboxylic acid concentration polymers because of the relatively large amount of cyclic dimer carboxylic acid group and poor amount of free carboxylic acid group. This study provides insight into interfacial proton transport behavior according to the weak acid concentration, which might explain proton transport in biological systems.

著者

Toshiaki INA Yuki ORIKASA Titus MASESE Takayuki NAKAO Atsushi MINESHIGE Koji AMEZAWA Hajime TANIDA Tomoya URUGA Yoshiharu UCHIMOTO

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.82, no.10, pp.875-879, 2014-10-05 (Released:2014-10-05)

参考文献数

41

被引用文献数

4

---

The relationship between the local structure and oxide ionic conduction of Nd2NiO4+δ possessing the K2NiF4 structure was investigated. Various oxygen nonstoichiometry samples of Nd2NiO4+δ prepared with different annealing oxygen partial pressures were examined. The local structure related to oxide ionic conduction was determined by the Nd K-edge extended X-ray absorption fine structure. The oxide ionic conductivity and surface exchange coefficient were estimated using electronic conductivity relaxation methods. The activation energy for the oxide ionic conductivity was found to have a direct correlation to the surface exchange coefficient. The bottleneck size for oxide ion conduction was strongly correlated to the oxide ionic conduction of interstitial oxygen and the oxygen surface exchange rate.

著者

Katsuhito TAKEI Nobuyuki SERIZAWA Tokujiro NISHIKIORI Yasuhiko ITO

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.86, no.2, pp.35-37, 2018-03-05 (Released:2018-03-05)

参考文献数

12

---

The cathodic reduction of nitrogen (N2) gas in molten chloride was investigated using a porous nickel (Ni) electrode. A LiCl-KCl-CsCl melt containing cathodically formed nitride ion (N3−) was sampled from an electrolytic bath and analyzed quantitatively by ion chromatography. The current efficiency of the cathodic reaction calculated from the ratio of quantity of the produced N3− was approximately 78% on average. The main reason why the measured efficiency did not reach 100% is considered as the amount of N3− increased more in the pores of the gas electrode than in the bulk of the electrolytic bath.

著者

清野 美勝

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.83, no.7, pp.576-577, 2015-07-05 (Released:2015-07-05)

著者

Ryosuke NAKAZATO Keeko MATSUMOTO Noboru YAMAGUCHI Margherita CAVALLO Valentina CROCELLÀ Francesca BONINO Matthias QUINTELIER Joke HADERMANN Nataly Carolina ROSERO-NAVARRO Akira MIURA Kiyoharu TADANAGA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.91, no.9, pp.097003, 2023-09-26 (Released:2023-09-26)

参考文献数

49

---

Carbon dioxide electrochemical reduction (CO2ER) has attracted considerable attention as a technology to recycle CO2 into raw materials for chemicals using renewable energies. We recently found that Zn-Al layered double hydroxides (Zn-Al LDH) have the CO-forming CO2ER activity. However, the activity was only evaluated by using the liquid-phase CO2ER. In this study, Ni-Al and Ni-Fe LDHs as well as Zn-Al LDH were synthesized using a facile coprecipitation process and the gas-phase CO2ER with the LDH-loaded gas-diffusion electrode (GDE) was examined. The products were characterized by XRD, STEM-EDX, BF-TEM and ATR-IR spectroscopy. In the ATR-IR results, the interaction of CO2 with Zn-Al LDH showed a different carbonates evolution with respect to other LDHs, suggesting a different electrocatalytic activity. The LDH-loaded GDE was prepared by simple drop-casting of a catalyst ink onto carbon paper. For gas-phase CO2ER, only Zn-Al LDH exhibited the CO2ER activity for carbon monoxide (CO) formation. By using different potassium salt electrolytes affording neutral to strongly basic conditions, such as KCl, KHCO3 and KOH, the gas-phase CO2ER with Zn-Al LDH-loaded GDE showed 1.3 to 2.1 times higher partial current density for CO formation than the liquid-phase CO2ER.

著者

Ryo SAKAMOTO Nobuaki SHIRAI Liwei ZHAO Atsushi INOISHI Hikari SAKAEBE Shigeto OKADA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.23-00041, (Released:2023-06-08)

被引用文献数

2

著者

Kentaro YAMAMOTO

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

pp.23-00032, (Released:2023-04-26)

参考文献数

36

被引用文献数

1

---

Electrode reactions in electrochemical devices often consist of charge transfer at electrode/electrolyte interface and charge compensation in electrode active material. Therefore, to design electrochemical devices with high electrochemical performance, it is important to understand electronic structures of the electrode/electrolyte interface and electrode bulk during electrochemical reactions, and to design electrode materials to control them. In this paper, certain phenomena at the electrode/electrolyte interface and electrode bulk in lithium-ion batteries are clarified by using synchrotron radiation X-ray analyses. The information obtained from those X-ray analyses are applied to control the structure of the electrode/electrolyte interface and electrode bulk. Moreover, new cathode materials for all-solid-state fluoride-ion with high power and cyclic performances have been developed, compared to simple metal/metal fluoride materials, by using the findings obtained from the synchrotron radiation X-ray analyses.

著者

Hisashi KATO Fumitada IGUCHI Hiroo YUGAMI

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.82, no.10, pp.845-850, 2014-10-05 (Released:2014-10-05)

参考文献数

24

被引用文献数

4 6

---

Sr2+, Al3+-doped LaScO3 perovskite-type oxide (La0.675Sr0.325Sc0.99Al0.01O3; LSSA), which exhibits high conductivity of both oxide-ion and proton, is expected to become an electrolyte material for high-temperature solid oxide fuel cells (SOFCs). Considering the potential of this material to serve as a solid electrolyte, its chemical compatibility with some of the typical fuel electrodes commonly used in SOFCs was investigated. Severe elemental diffusion was found at the sintering temperature of 1673 K between doped LaScO3 and the anode material, mainly due to strontium migration. To control the elemental diffusion, we lowered the sintering temperature to 1523 K. In the case of Ni-SDC, we found no elemental diffusion at the electrolyte/electrode interface. Moreover, we tried to fabricate SOFC consisting of LSSA electrolyte and some electrodes, and we performed power generation tests above 1073 K. At 1273 K, the maximum power density was 158 mW cm−2 as humidified hydrogen fuel. The electrolyte resistance was high due to the high thickness of 0.6–0.9 mm. Higher power density would seem possible if a thinner electrolyte is applied. Consequently, we found that LSSA is applicable as an electrolyte material for SOFCs.

著者

Naruhisa TSUKASE Konosuke WATANABE Takuto ARAKI Kensaku NAGASAWA Shigenori MITSUSHIMA

出版者

The Electrochemical Society of Japan

雑誌

Electrochemistry (ISSN:13443542)

巻号頁・発行日

vol.90, no.12, pp.127002, 2022-12-14 (Released:2022-12-14)

参考文献数

25

被引用文献数

1

---

Polymer electrolyte membrane (PEM) water electrolysis has received significant attention as a suitable technology for hydrogen production because it can operate at a high current density, is compact, and can produce high purity hydrogen. However, this process involves high costs because precious metal catalysts are required to maintain high performance. To overcome this challenge and develop new materials to replace precious metals, the complex overlapping overpotentials must be considered separately. In a previous study, a structure that uses double reference electrodes by shifting the electrode arrangement was proposed for separating the overpotentials. This structure allows the electrolyte surface potential to be measured by a reference electrode far from the electrode by changing the potential distribution. However, the structure may cause a complicated three-dimensional potential distribution, which may adversely affects accurate measurement of the electrode potential. Therefore, the potential distribution was analyzed and evaluated using three-dimensional multiphysics simulations incorporating proton and electron conduction. As a result, a remarkable phenomenon called potential wraparound, which affects the distribution of electric potential, was observed. Furthermore, a significant finding was that this effect can be suppressed by changing the shape of the electrode.