bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discovering Pd-B/C As a Potential Bifunctional Catalyst in the Formic Acid ↔ Carbon Dioxide Conversion Cycle
Authors: Jiang Bei , Jiang Kun , Cai Wen-Bin 
Published: February 2020

It is well known that facile interconversion of HCOOH and CO2 is very important in hydrogen production, direct formic acid fuel cell, as well as neutral emission of CO2. In the past few years, we have investigated chemical and electrochemical dehydrogenation of formic acid over Pd-B/C and Pd/C, revealing that significantly enhanced dehydrogenation of HCOOH can be achieved on the home-synthesized Pd-B/C[1-3]. B-doping in the Pd lattice can be attained during the reduction of a Pd(II) precusor from an aqueous solution using dimethylamine borane as the reducing agent and boron source[1]. The XRD result suggested the expansion of Pd lattice and the XPS result indicated the partial electron transfer from B to Pd [3], lowering down the d-band center of Pd, favoring the dehydrogenation pathway, as supported by latest DFT calculation by Studt and Norskov[4]. In situ ATR-IR spectroscopy on Pd-B/C and Pd/C was comparatively conducted in conditions mimicking hydrogen production or direct formic acid fuel cell, it is revealed that desired dehyrogenation pathway forming CO2 is enhanced accompanied with inhibited accumulation of CO poissoning specie on Pd-B/C [2-3]. Since both forward and backward conversions may involve the weakly adsorbed formate as an active intermediate, it is thus interesting to explore the use of Pd-B/C as the catalyst for electroreducing CO2 to form HCOOH. Indeed, our recent preliminary analysis on the products of CO2 electroreduction over Pd-B/C and Pd/C catalysts in a KHCO3 electrolyte indicates that the formation of HCOOH on Pd-B/C is greatly enhanced as compared to that on Pd/C.

Acknowledgements
：Financial supports from NSFC (grant No. 21273046 and 21473039）and the 973 Program (No. 2015CB932303) of MOST are highly appreciated

References
：

[1] J.Y. Wang, Y.Y. Kang, H. Yang, and W.B. Cai, J. Phys. Chem. C
,
113, 8366 (2009).
[2] K. Jiang, K. Xu, S.Z. Zou, and W.B. Cai, J. Am. Chem. Soc., 136, 4861 (2014).
[3] K. Jiang, J.F. Chang, H. Wang, S. Brimaud, W. Xing, R. J. Behm, and W.B. Cai , ACS Appl. Mater. Interfaces, 8, 7133(2016)
[4] J. S.Yoo, Z.-J. Zhao, J. K. Nørskov, and F. Studt, ACS Catal., 5, 6579 (2015).
Insights from Near-Surface Atomic Structures and Composition for Catalytic Activity and Stability of Oxides in Electrochemical Reactions
Authors: Feng Zhenxing , Shao-Horn Yang 
Published: February 2020

Electrocatalysts play an important role in catalyzing the kinetics for many reactions (e.g., oxygen reduction reaction, oxygen evolution reaction and CO2photoelectrochemical reduction) for many energy storage and conversion devices, such as metal-air batteries, electrolyzer and fuel cells. Although oxides are promising catalysts due to their natural abundance, low cost, and widely tunable properties, the design of oxide electrocatalytic functionality is not straightforward due to the lack of information on the oxide surface atomic structure and chemistry.
Using a combination of in situ surface-sensitive X-ray diffraction and spectroscopy methods, we have studied several electrochemical devices (e.g., (La0.5Sr0.5)2CoO4+δ/La1-x
Sr
x
CoO3-δ/GDC/YSZ heterostrucured cathodes for solid oxide fuel cells, spinel oxides for supercapacitors, LiMn2O4 for batteries) and model systems (e.g., La1-x
Sr
x
CoO3-δ/SrTiO3 for fuel cells and MgMn2O4 thin film for battery cathodes) to obtain their near-surface atomic structures and composition changes during various electrochemical reactions. The information we learned provides critical insights about the dynamic changes of oxides during the electrochemical reactions and their influences on alternating reaction paths for optimizing ORR/OER and CO2 reductions. Based on these findings, we have figured out strategies to control the oxide surfaces for the enhanced activity and better stability for fuel production, energy storage, and CO2 reduction.

References:

(1) Z. Feng, W. T. Hong, D. D. Fong, Y.-L. Lee, Y. Yacoby, D. Morgan, and Y. Shao-Horn, Accounts of Chemical Research, accepted, 2016
(2) K. A. Stoerzinger, W.T. Hong, E.J. Crumlin, H. Bluhm, and Y. Shao-Horn, Accounts of Chemical Research, 48, 2016, 2976-2983.
(3) Z. Feng, X. Chen, L. Qiao, A.L. Lipson, T.T. Fister, L. Zeng, C. Kim, T. Yi, N. Sa, D.L. Proffit, A.K. Burrell, J. Cabana, B.J. Ingram, M.D. Biegalski, M.J. Bedzyk, P. Fenter, ACS Applied Materials & Interfaces, 7, 2015, 28438-28443.
Ionic Liquids and Organic Ionic Plastic Crystals Based on Tris(fluorosulfonyl)methide
Authors: Matsumoto Hajime , Mizukado Junji , Wan Peng-cheng 
Published: February 2020

Ionic liquids (ILs) composed of low coordinating anions such as perfluoroanions have been studied as a unique electrolyte for a lithium battery for past two decades.[1] The best performance of a lithium battery system using only ILs was achieved by bis(fluorosulfonyl)amide (FSI-, FSA- or f2N-) [2]. The existence of FSO2- group in f2N-
might cause such a good performance. In this study, we tried to prepare new perfluoromethide, tris(fluorosulfonyl)methide (f3C-) to investigate the effect of FSO2
- group on physicochemical and electrochemical properties of onium salts composed of f3C-. The physical, thermal and electrochemical properties of the ILs were compared to another similar methide anion (tris(trifluoromethylsulfonyl)methide, Tf3C-). The Tf3C- could form ILs with conventional cations such as N-ethyl-N-methylimidazolium (C1C2im+) and N,N-dimethyl-N-methyl-N-(2-ethoxymethyl)ammonium (N2,2,1,2O1
+), however, It was quite interesting that the f3C- had a tendency to form organic ionic plastic crystals (OIPCs) rather than ILs. As far as we know, the N2,2,1,2O1
+ forms ILs with various anions even PF6
-
[3] however, the f3C- forms good OIPCs with N2,2,1,2O1
+ (T
m
= 69 °C, T
s-s = -29 °C).
The cathodic limiting potential of a ILs composed of N-ethyl-N-methylimidazolium (C1C2im+) and f3C- was about 1.0 V shifted toward negative potential with adding Lif3C and stable lithium deposition and redissolution cycle could be successfully observed. The apparent charge transfer resistance at an interface between a Li metal and [C1C2im][f3C] was more stable over 18 months than that for [C1C2im][Tf3C], which indicated that the existence of FSO2- group in a perfluoroanion must be importance to maintain a stable SEI on the lithium metal as previously reported in a bis(fluorosulfonyl)amide based melts.[3] Furthermore, the apparent charge transfer resistance at a charged LiCoO2 composite electrode (4.2 V vs Li/Li+) in the [C1C2im][f3C] was almost the same value during over 500 charge and discharge cycles, which suggested that the good electrochemical stability not only for a lithium metal but also for the charged cathode were achieved with using the new methide f3C- composed of FSO2
- group as in bis(fluorosulfonyl)amide based melts. These results suggest that the FSO2
- group have an essential moiety to design an novel perfluoroanions for a lithium battery electrolyte. The f3C-provided not only ILs as a novel lithium battery electrolyte but also OIPCs and the molecular design rules, which have not yet been clearly understood.

Acknowledgment

This study was financially supported by JST, ALCA-SPRING project.

References

[1] H. Matsumoio. in Electrolytes for Lithium-ion Batteries, T. R. Jow, K. Xu., O. Borodin and M. Ue, Eds., Springer. 2014, ch. 4, and references therein.
[2] H. Matsumoto, H. Sakaebe, K. Tatsumi, M. Kikuta, E. Ishiko, M. Kono, J. Power Sources, 160(2), (2006) 1308.
[3] H. Matsumoto, H. Sakaebe, K. Tatsumi, ECS Transactions,16(35), (2009)59.

Figure 1
Fluorination Behavior of Uranium-Zirconium Mixture by Hydrogen Fluoride
Authors: Ono Takahiro , Sato Nobuaki , Nezu Atsushi , Uchiyama Takafumi , Matsuura Haruaki 
Published: February 2020

Due to the accident of Fukushima Daiichi nuclear power plant, fuel debris has been produced inside the nuclear reactor vessels. It would be very difficult to reprocess such fuel debris by using normal procedures, since the fuel debris may contain surrounding structural material. To reprocess fuel debris, a pyroprocess of selective fluorination and a molten salt electrolysis have been proposed. The advantage of pyroprocess is to decrease the volume of radioactive wastes and on-site treatment. The proposed method consists on a selective fluorination, a selective dissolution, and a molten salt electrolysis. The aim of this study is to investigate the fluorination behavior of uranium – zirconium oxide mixture.
All experiments was performed at Institute of Multidisciplinary Research for Advanced Materials, Tohoku University. The samples of uranium – zirconium mixtures have been prepared as follows. First, UO2 was made by the reduction using Ar – H2 mixture gas for U3O8 at 1000oC. Second, UO2 and ZrO2 were mixed by the molar ratios of 1:9, 3:7, 5:5, 7:3 and 9:1. Finally, these samples were treated in the environment of either oxidation or reduction. To evaluate fluorination behavior of these mixtures, a thermogravimetric differential thermal analyzer and a powder X-ray diffractometer. Each sample was set in a platinum pan inside the chamber of TG-DTA and hydrogen fluoride gas in 60 ml/min was introduced in it. In the TG-DTA, temperature raising rate was 5oC/min or 10oC/min until 500oC. Finally, the samples used for the TG-DTA were characterized by the XRD.
In the zirconium rich mixtures, rapid fluorination reaction occurs at relatively higher temperature (400oC), while in the uranium rich mixtures, slow fluorination reaction occurs at relatively lower temperature. Depending on pre-treated environment of the mixtures, the difference of fluorination behavior is identified. In general, relatively slower fluorination reaction occurs in the mixtures pre-treated in oxidation environment, while rapid fluorination occurs in the mixtures pre-treated in reduction environment. These facts would be caused by either degree of amount of solid solution in the mixtures or morphology of samples. How much degree of fluorination is the best to introduce into molten salt is going to under consideration.
This work was supported by Network Joint Research Center for Materials and Devices, 2015223 and JSPS Kakenhi 15K0665.
Intermediate-Temperature Operation of Sodium Secondary Batteries with High Rate Capability and Cyclability Using Ionic Liquid Electrolyte
Authors: Matsumoto Kazuhiko , Chen Chih-Yao , Kiko Tomohiro , Hwang Jinkwang , Hosokawa Takafumi , Nohira Toshiyuki , Hagiwara Rika 
Published: February 2020

Ionic liquid electrolytes are widely studied to construct safe electrochemical devices owing to their unique properties such as low volatility, low flammability, and wide liquid-phase temperature range.
Ionic liquids based on sulfonylamide anions (bis(fluorosulfonyl)amide anion (FSA-) have low melting point, low viscosity, and high ionic conductivitysome and are attractive as electrolytes in secondary batteries. The present study reports physical and electrochemical properties of FSA-based ionic liquid electrolytes for secondary betteries operating from room temperature to intermediate temperature. Intermediate operation of secondary batteries in is available in some circumstances such as an engine compartment of automobiles and is preferable to enhance both the ion transport and electrode reactions.
The Na[FSA]-[C3C1pyrr][FSA] (C3C1pyrr+ = N-methyl-N-propylpyrrolidinium) and Na[FSA]-[C2C1im][FSA] (C2C1im+ = 1-ethyl-3-methylimidazolium) ionic liquid systems have wide liquid phase temperature ranges around room temperature and high ionic conductivities [1,2].
Immersion of Na metal in FSA- and TFSA-based ionic liquids clearly showed that FSA-based ionic liquids form stable film on Na metal to prevent futher reduction. Dendrite formation during Na metal electrodeposition is suppressed by increasing temperature. Excellent rate capability and cycle property were observed for the Na2FeP2O7 positive electrode in FSA-based ionic liquids at 363 K.[3] The origin of this performance will be discussed based on transport properties of Na+ by considering transport number and Na+fraction in these ionic liquids.
Acknowledgements:
This study was partly supported by Advanced Low Carbon Technology Research and Development Program (ALCA) of Japan Science and Technology Agency (JST) and Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) program “Elements Strategy Initiataive to Form Core Research Center”.
References
[1] K. Matsumoto, T. Hosokawa, T. Nohira, R. Hagiwara, A. Fukunaga, K. Numata, E. Itani, S. Sakai, K. Nitta, S. Inazawa, J. Power Sources, 2014, 265, 36-39
[2] K. Matsumoto, Y. Okamoto, T. Nohira, R. Hagiwara, J. Phys. Chem. C, 2015, 119, 7648-7655.
[3] C. Chen, K. Matsumoto, T. Nohira, C. Ding, T. Yamamoto, R. Hagiwara, Electrochim. Acta, 2014, 133, 583-588.
"Click Synthesis" of Mercaptosilyl-Functionalized Ionic Liquids via Thiol-Ene Chemistry for Use as Hydrophobic Surface Coating Agents
Authors: Sanchez Zayas Manuel , Nestor Stephen , Gaitor Jamie , Reardon Melissa , Mirjafari Arsalan 
Published: February 2020

The thiol-ene “click” transformation described here is a high-yielding and simple fusion process, leading to a series of hydrophobic, multifunctionalized ionic liquids containing long thioether spacers (C7−C15) with low melting points and high thermal stability. The process exhibits broad scope and provides a series of imidazolium, ammonium and phosphonium-based mercaptosilyl-functionalized ionic liquids (16 examples) in excellent yields and exclusive anti-Markovnikov regioselectivity. In order to aid in defining their practical range of use in various applications, the thermophysical properties of the new ionic liquids such as glass transition temperature, decomposition temperature, viscosity and density along with their water contents, were studied. The mercaptosilane class of ILs can have important applications due to their hydrophobicity, moderately low viscosities, high thermal stabilities and wide liquids range. The synthesized ionic liquids were found to be active surface coating agents and were successfully immobilized on magnetite supermagnetic Fe3O4 nanoparticles. The representative ionic liquids with different side chains were immobilized on the surface of Fe3O4 supermagnetic nanoparticles and showed high organic loading (27.40−39.81 wt%) and low size of nanoparticles (6.72−10.12 nm). The ability to introduce trimethoxysilane into the structures of ionic liquids would open new horizons for their applications such as surface modification and hybrid materials. The incorporation of a thiol group to the structure of silane-functionalized ionic liquids could be utilized to construct novel organic-inorganic materials due to strong affinity of thiols to specific metallic surfaces.
Electrochemical Synthesis of Nanomaterials in Molten Salts
Authors: Kuznetsov Sergey A. 
Published: February 2020

For the first time by electrochemical synthesis from NaCl-KCl-NaF-GdF3-KBF4 melt at temperature 1023 K and with utilization of molybdenum cathode the gadolinium hexaboride nanotubes were synthesized. Most likely GdB6 nanotubes formation is ruled by intercalation mechanism. Gadolinium hexaboride lattice is the framework of boron atom octahedrons, in gaps of which the gadolinium atoms are situated. These gaps are spacious enough to host the metal atoms without deformation and even with reserve of vacant space. Electrochemical synthesis of GdB6 occurs at potentials negative enough for alkali metal cations electroreduction. So alkali metal cations intercalate into the emptiness of hexaboride lattice where cations are reduce in situ. The metal atoms have larger radius than its cations so they provoke mechanical strain. At the certain value of the strain GdB6 splits with nanotubes formation.
Nanoneedles of TaO with tetragonal crystal lattice were obtained by electrolysis of CsCl melt, containing monooxofluoride complexes of tantalum. It was determined the correlation between the redox potential of molten system, temperature and stability of tantalum monoxide.
Multi-layered tantalum boride structures were produced via electrolysis in the NaCl-KCl-NaF-K2TaF7-KBF4 melt. The overall thickness of the layers, synthesized under direct current regime, was 30-50 μm, and they consisted of numerous fine layers (nanolayers).
A new generation of highly active and stable catalytic nanostructured coatings for the water-gas shift reaction by high temperature electrochemical synthesis in molten salts has been developed. The steady-state reaction rates for the Mo2C/Mo coatings were higher than those for the bulk Mo2C and commercial Cu/ZnO/Al2O3 catalysts over in the temperature range explored. The catalytic activity is enhanced by at three orders of magnitude comparing to that of the pure Mo2C phase. The methanation reaction was completely suppressed in the whole temperature range studied on the Mo2C/Mo systems. The catalytic activity remained constant during 5000 hours on-stream. The coatings were also stable during the thermal cycling, while the activity of commercial catalysts tends to decrease with time. A novel microstructured reactor/heat-exchanger containing eight sections with a cross-section of 10 mm x 10 mm and a length of 100 mm has been designed and constructed. Each section of the reactor contains flat, perforated Mo plates and Mo wires with a diameter of 250 mm and a length of 100 mm coated with a porous Mo2C layer.
Nanoneedles of silicon were obtained in chloride-fluoride melts containing K2SiF6 by potentiostatic electrolysis which accompanied by reaction of disproportionation.
Electrolytic Production of Aluminium Using Gas Anode Supplied with Methane
Authors: Khalaghi Babak , Haarberg Geir Martin , Kjos Ole Sigmund , Gudbrandsen Henrik , Osen Karen Sende , Mokkelbost Tommy 
Published: February 2020

Mitigation of carbon emissions from the aluminium electrolysis cell is one of the main research topics of the aluminium industry. Prolonged research on inert anode candidates has not led to a commercial product yet. Another approach is to apply a reducing gas, e.g. methane, to the bath through porous anodes; where it reacts with oxygen-containing ions of the bath. When the gas (methane) replaces the consumable anode in reacting with the bath, the amount of generated CO2is reduced substantially. However, if the porous anode is made of carbon, the anode itself also takes part in the anodic reaction to some extent. Therefore, the consumption of the reducing gas and the anode occur simultaneously.
Aluminium electrolysis experiments were carried out using porous graphite electrodes supplied with methane. The potential and weight changes of the anode together with the off gas analyses were done to study the effect of methane supply. It was found that the supply of methane during electrolysis led to decreased consumption of the graphite anode. But at the same time, the level of HF in the off gas showed a noticeable rise, which was expected due to the formation of water from methane oxidation. Provided that the share of the methane in the anodic reaction increases, the anode will be consumed less and a smaller amount of CO2is generated. Different grades of graphite were tested. Moreover, experimental parameters such as current density and anode gas composition were varied.
Figure below: Anode potential plotted against time during aluminium electrolysis for two experiments where in one (top) only N2 and in the other (below) N2 + CH4 were flushed through the porous anodes. The anode was made of isotropic graphite. i = 0.4 A.cm-2, T = 970°C. The values in the figure are flow of the gas in ml.min-1.

Figure 1
Rest Potentials of Binary Mixtures of Ionic Liquids and Threshold Voltages of Electric-Double-Layer Transistors
Authors: Nanjo Chihiro , M. Matsushita Michio , Awaga Kunio 
Published: February 2020

There is a growing attention to the electric-double-layer (EDL) transistors, in which electrolytes are adopted as gate dielectrics, because a strong electric field produced by EDLs improves transistor performance. In our previous study, we investigated the relation between the rest potentials and the threshold voltages of EDL transistors, using two kinds ambipolar phthalocyanines and various ionic liquids. It was found that the rest potential is a unique property of ionic liquid, and the threshold voltages of the EDL transistors are proportional to the rest potentials of the ionic liquids. This means that the threshold voltages of the EDL transistors can be tuned by controlling the rest potentials, though what determines the rest potentials of the ionic liquids is still unclear.

In the present study, we tried to understand the rest potentials of the ionic liquids and to control the threshold voltages of the EDL transistors, by making the binary mixtures of ionic liquids, because their mixing ratios can be continuously changed. We prepared the binary mixtures of the ionic liquids, combining DEME-TFSI and five kinds of ionic liquids, shown in the inset of Figs. 1 and 2. These combinations were selected, because these ionic liquids are miscible each other and the rest potential of DEME-TFSI is higher than those of the others.

The rest potentials of the binary ionic liquids were examined with an Ag/AgCl reference electrode and a Pt working electrode. The rest potentials of the binary ionic liquids were found to change non-linearly with respect to the mixing ratio of the ionic liquids (Fig. 1). This dependence can be well fit to the equation of y = a + b*log(x), where x is the mixing ratio and, a and b are the fitting parameters. This strongly suggests that the rest potential of ionic liquid is governed by its chemical potential μ, because this equation has the same form as that of the chemical potential, μ = μ
0 + RTln(x), where R is the gas constant. Then, we tested the EDL transistors of platinum phthalocyanine (PtPc) which showed a high stability even in various ionic liquids. It was found that there was a linear relation between the rest potentials and the threshold voltages of the EDL transistors (Fig. 2), and the threshold voltages can be continuously controlled by changing the mixing ratio of the ionic liquids.

Figure 1