bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Behavior of Cobalt and Samarium Species in an Amide-Type Ionic Liquid
Authors: Manjum Marjanul , Serizawa Nobuyuki , Katayama Yasushi 
Published: February 2020

Rare earth-transition metal alloys/nanoparticles (NPs) have drawn intensive significance in a wide range of applications in automobiles, data storage, magnetoelectronic, electromechanical, and electronic devices due to their excellent magneto-crystalline anisotropy. Among them, cobalt (Co)-samarium (Sm) alloys are of great interest. Although there are many reports on the preparation of Co-Sm alloys in different media by different techniques, the electrodeposition of Co-Sm alloys/NPs has not been confirmed in an aprotic ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA), which has high cathodic stability. In the present study, the electrochemical behavior of Co and Sm species was investigated in BMPTFSA at different temperatures.
Co(TFSA)2 and Sm(TFSA)3 were prepared by the reactions of CoCO3 and Sm2O3 with HTFSA, respectively, and dissolved in BMPTFSA 1-3. Electrochemical measurements were conducted with an air-tight cell using glassy carbon (GC) as a working electrode, a Co wire as a counter electrode, and an Ag wire immersed in 0.1 M AgCF3SO3/BMPTFSA as a reference electrode.
Potentiostatic cathodic reduction at –2.5 V on a GC electrode was conducted in BMPTFSA containing 30 mM Co(TFSA)2 and 5 mM Sm(TFSA)3 at 25 and 100 oC. The lower concentration of Sm(III) was preferred than that of Co(II) because of the difference in the diffusion coefficients of Co(II) and Sm(III) ions in BMPTFSA. Deposits on the GC electrode surface were found after electrodeposition. The presence of Co and Sm in the deposits was confirmed by scanning electron microscopy and energy dispersive X-ray spectroscopy. The deposits were found to be amorphous by X-ray diffraction. In addition, the electrolyte after electrolysis was examined by transmission electron microscopy (TEM). The formation of the NPs with lattice fringes was confirmed by TEM. The spots observed in the electron diffraction image of the NPs could be assigned to (111) and (110) planes of SmCo7. EDX confirmed the presence of Co and Sm in the NPs. Therefore, SmCo7 NPs were considered to be prepared in this ionic liquid.
References
1. Y. Katayama, R Fukui, and T Miura, J. Electrochem. Soc., 154, D534 (2007).
2. Y. Katayama, R Fukui, and T Miura, Electrochemistry,
81, 532 (2013).
3. M. Yamagata, Y. Katayama, and T. Miura, J. Electrochem. Soc., 153, E5 (2006).
New Reference Electrodes for Air and Moisture Stable Ionic Liquids
Authors: Horwood Corie , Stadermann Michael 
Published: February 2020

The use of room temperature ionic liquids (RTILs) for electrochemical applications such as fuel cells, batteries, dye-sensitized solar cells, and supercapacitors, has gained significant interest over the last decade. Despite the increase in attention, a universal reference electrode for use in RTIL electrochemistry has not been adopted. A stable, easy to prepare, and reproducible reference electrode, analogous to Ag/AgCl reference electrodes for aqueous electrochemistry, is crucial for accurately determining redox potentials as well as for comparing these potentials between RTILs and between research labs.
Electrochemical work in RTILs often rely on quasi-reference electrodes (QREs),1 such as Ag or Pt wire, which must be calibrated by the addition of a redox couple (e.g. ferrocene/ferrocenium) after each electrochemical measurement. These quasi-reference electrodes are difficult to reproduce, likely due to the quality of the wire used and the presence of surface adsorbates. Furthermore, they have been known to exhibit potential drift during use, with 10s to 100s of mV drift often observed. Ferrocene is added after the experiment, however this one-point calibration of the QRE does not necessarily apply throughout the entire experiment, as the QRE may drift during the measurement.2

We report on reference electrodes designed for use in ionic liquids, which exhibit stable potential over several months of experimental use. One successful example is based on a silver wire coated with silver sulfide.3 The reference electrode potential is determined by the concentrations of Ag+ and S2
−, which are established by the solubility of the Ag2S coating on the Ag wire. Our reference electrode can be prepared and used in a normal air atmosphere, and does not need to be assembled and used in a glovebox, or protected from light. The reference electrode has been characterized by voltammetry measurements of ferrocene and cobaltocenium hexafluorophosphate, and was found to slowly drift to more positive potentials at a rate of <1 mV/day for five RTILs investigated over the course of 2+ months.
Funding was provided by Lawrence Livermore National Laboratory Directed Research and Development (LDRD) Grant 17-ERD-047. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. IM release LLNL-ABS-748348.
(1) Electrochemical aspects of ionic liquids, 2nd ed.; Ohno, H., Ed.; John Wiley & Sons Inc., 2011.
(2) Torriero, A. A. J.; Sunarso, J.; Howlett, P. C. Electrochim. Acta
2012, 82, 60–68.
(3) Horwood, C.; Stadermann, M. Electrochem. commun.
2018, 88, 105–108.
Stacked Additively Manufactured Electrochemical Cell for Reduction of Carbon Dioxide to Ethylene
Authors: Ball Keiran , Tacon Christopher , Reeve Sam , Perry Samuel Charles , Ponce de Leon Carlos 
Published: February 2020

An additively-manufactured two-cell stack is presented for the reduction of carbon dioxide to ethylene, forming part of a Horizon 2020 funded project, CO2EXIDE, which aims to recycle carbon dioxide in order to reduce greenhouse gas emissions1.

In this work we present a new compact flow field design, which allows for an easily expandable cell stack through the manufacture of additional identical bi-polar flow fields2. The flow fields are manufactured from 316L stainless steel using the 3D printing technique – Direct Metal Laser Sintering (DMLS). This allows them to simultaneously act as the flow fields and current collectors. The DMLS technology enables complex internal pipework, shown in figure 1, which allows a compact cell with no external pipework.
Our cell design is built around a membrane electrode assembly (MEA) (see figure 2), where CO2 is reduced at the cathode and water is oxidised at the anode3. The cathode is made from a copper nanoparticle catalyst, which is deposited onto a carbon gas diffusion layer. A nickel mesh is used as a catalyst for the anodic reaction. The flow fields were designed and optimised using the ANSYS Fluent 19.1 software in order to maximise residence time within the cell and ensure a similar pressure drop on each side of the MEA, which are essential to provide high reaction selectivity and to avoid pressure driven fluid transport across the proton exchange membrane respectively. Designing the flow field in this way allowed us to optimise our cell for both high ethylene yield and a long working life time (see figure 3 for the flow field pattern).
The finished assembly (see figure 4) was analysed for its ability to selectively reduce CO2 to ethylene. CO2 was flowed over the cathode at varying flow rates, and the outflow gas was collected for ex situ analysis by gas chromatography. This design is promising for the future development of CO2 as a carbon source for ethylene, as the stackable design makes this assembly more easily scalable for large scale operations.

[1] CO2EXIDE, “CO2EXIDE - CO2-based electrosynthesis of ethylene oxide,” 2018. [Online]. Available: http://www.co2exide.eu/. [Accessed 12 March 2019].
[2] O'Neil, Glen D.; Ahmed, Shakir; Halloran, Kevin; Janusz, Jordyn N.; Rodriguez, Alexandra; Terrero Rodriguez, Irina M. Single-step fabrication of electrochemical flow cells utilizing multi-material 3D printing. Electrochemistry Communications 99 (2019) 56-60.
[3] DeWulf, D.W.; Jin, T.; Bard, A.J. Electrochemical and Surface Studies of Carbon Dioxide Reduction to Methane and Ethylene at Copper Electrodes in Aqueous Solutions. Journal of the Electrochemical Society. 136(6) (1989) 1686-1691.

Figure 1
Developing Platinum Group Metal Free Catalysts with Multiple Metal Centers for the Oxygen Reduction Reaction in Acid
Authors: Jiao Li , Liu Ershuai , LaRochelle Richard Lynne , Mukerjee Sanjeev , Jia Qingying 
Published: February 2020

Remarkable advancement of Platinum group metal-free (PGM-free) catalysts for the oxygen reduction reaction (ORR) in acidic media makes it potentially feasible as an alternate to Pt-based catalysts in polymer electrolyte fuel cells (PEMFCs). The current leading PGM-free catalysts are composed of single transition metal atoms embedded in microporous nitrogen-doped carbon matrix (M-N-C). The commercialization of M-N-C catalysts in PEMFCs has been impeded by the insufficient activity and particularly durability. The limited ORR performance is likely owing to the single metal center configuration that causes low active site density, undesired O2 binding configuration and energy toward the metal center, etc. These inherent limitations of M-N-C catalysts motivate us to move toward Mx-N-C with multiple metal center (MMC) sites.
On account of this, herein a multidentate ligand platform is utilized to prepare a series of bimetallic coordination complexes. These complexes were then used as the metal precursors to produce Mx-N-C with MMC sites by incorporating them into microporous nitrogen-doped carbon matrix via both pyrolysis and surface deposition approaches without breaking the pre-existing multiple nuclear structure. The formation of MMC sites is supported by multiple characterizations. The high ORR activity achieved is tentatively related to MMC sites that promotes the desorption of oxygen adsorbates and suppress the site-blocking effect at elevated potentials. Further improvement, however, is limited by the low concentration of MMC sites. densification of MMC sites is undergoing.

Acknowledgement

This work was supported by the US Department of Energy under award number DE-EE0008416. The authors declare no competing financial interests. MRCAT operations are supported by the Department of Energy and the MRCAT member institution. This research used resources of the Advanced Photon Source, a DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
(Invited) Recycling of Used Li-Ion Batteries By Innovative Electrodialysis Using New Lithium Ionic Conductor Membrane
Authors: Hoshino Tsuyoshi 
Published: February 2020

As a means of addressing global warming, the world is increasingly turning to the use of Li-ion batteries in electric vehicles and as storage batteries in the home; therefore, there is a growing need for Li. I have developed a method for the recovery of Li from used Li-ion batteries using a Li ionic conductor functioning as a Li-ion separation membrane (LISM).
This innovative method involves the use of an LISM whereby only Li ions in a solution of used Li-ion batteries permeate from the positive electrode side to the negative electrode side during electrodialysis; the other ions, including Co, Al, and F, do not permeate the membrane. Li0.29La0.57TiO3 was selected as the LISM. The positive side of the dialysis cell was filled with used Li-ion battery solution. Then the negative side was filled with distilled water. The applied dialysis voltage was 5 V, and electrode area was 16 cm2. The Li recovery ratio increased with electrodialysis time. Then, Co, Al, and F were not permeated (Fig.1).
Measurements of the Li ion concentration at the negative electrode side as a function of dialysis duration showed that the Li recovery ratio increased to approximately 90% after 72 h. Moreover, other ions in the seawater did not permeate the LISM. With both ends of the LISM bound with a negative and positive electrode, hydrated Li ion was transformed to Li ion only because Li ion can permeate through the LISM [1].
After electrodialysis, CO2 gas was bubbled in the Li recovery water to produce lithium carbonate (Li2CO3) as a raw material for Li-ion batteries. The Li2CO3 deposition was easily generated by the reaction of CO2 gas and the Li recovery solution as a lithium hydroxide (LiOH) solution (Fig.2). Moreover, the purity of Li2CO3 is up to 99.99%.
This new method for recycling Li-ion batteries shows good energy efficiency and is easily scalable. Thus, this electrodialysis method is suitable for the recycling of Li from used Li-ion batteries.
Fig.1 Schematic of Li recovery from Li-ion battery solution using the proposed electrodialysis.
Fig.2 Production of High-purity Li2CO3 by CO2 bubbling method.
[1] T. Hoshino, Desalination, 359, 59-63 (2015).

Figure 1
(Keynote) Solid State Ionics; Applying What I Learned from Bob Huggins to Advancing Electrochemical Energy Conversion and Storage
Authors: Wachsman Eric D. 
Published: February 2020

Research in functional materials has progressed from those materials exhibiting structural to electronic functionality. The study of ion conducting ceramics ushers in a new era of "chemically functional materials." This chemical functionality arises out of the defect equilibria of these materials, and results in the ability to transport chemical species and actively participate in chemical reactions at their surface. Moreover, this chemical functionality provides a promise for the future whereby the harnessing of our natural hydrocarbon energy resources can shift from inefficient and polluting combustion - mechanical methods to direct electrochemical conversion.
The unique properties of these materials and their applications will be described. The focus will be on the application of ion conducting ceramics to energy conversion and storage, chemical sensors, chemical separation and conversion, and life support systems. Results presented will include development of record high conductivity electrolytes, record high power density solid oxide fuel cells, solid-state Li-batteries, NOx/CO species selective solid-state sensors, high yield membrane reactors, and regenerative life support systems that reduce CO2 to O2 and solid C.
Side-View Operando microscopy of Graphite Anodes to Understand Kinetic Hysteresis
Authors: Kang Sujin , Yeom Su Jeong , Lee Hyun-Wook 
Published: February 2020

Operando imaging analysis has emerged as a promising characterization tool for the observation of nanoscale processes; chemical synthesis, electrochemical reaction, and physical interaction of various materials. For past a decade, operando microscopy tools have contributed to understanding the lithiation or sodiation behaviors in battery materials for discovering new electrode materials with high performance and identifying the fundamental failure mechanisms that prevent a prolonged cycle life. Among the candidates, graphite anodes have the most promise to apply for lithium-ion batteries, but also have scientific challenges to retain their kinetics upon repeated charge and discharge cycles. To develop a better design of the electrodes, understanding graphite anodes with direct observation has created a high interest. Although such demands lead to extensive studies about operando imaging techniques, the observation is mostly limited for a single particle or a particular position of the electrodes.
In this regard, we have demonstrated side-view operando optical microscopy on graphite anodes by a change of color during electrochemical lithiation. Since the color of graphite changes owing to the different bandgap during lithiation and delithiation processes, operando optical microscopy enables to analyze the kinetics of charge and discharge behaviors. In addition, our cell configuration has the manifold advantages of applying and adjusting liquid electrolytes which is similar to commercial cells as a practical application and offering the investigation of the electrode side view. The side-view observation of an electrode level is found that microscale spatial variations in rate and composition control the insertion and desertion to understand the kinetics through the whole electrode. Our results allow for a better fundamental understanding of kinetics in battery materials.
Sustainable Electrochemical Conversion of Lignin to Renewable Chemicals with Simultaneous Hydrogen Production Via a Continuous Flow Electrochemical Reactor
Authors: Ghahremani Raziyeh , Staser John A. 
Published: February 2020

Lignin is the most abundant renewable source of aromatic compounds which can be utilized to generate fuels, chemicals, and polymers, however, due to the lack of an efficient lignin conversion process, it is usually burned as a low-grade fuel in the pulp and paper industry [1,2]. The key issue for commercial application of lignin is to develop an efficient depolymerization process to produce lower molecular weight aromatic compounds at relatively low cost. Several methods including photocatalytic degradation, hydrogenolysis, thermolysis, oxidation, biodegradation, and electrocatalytic degradation have been used to convert lignin to other value-added chemicals. Among them, electrochemical valorization of lignin is likely a promising method for commercial application due to occurring in moderate reaction conditions. Lead dioxide is one of the common active catalysts for electrochemical lignin oxidation [3]. However, due to the toxicity of lead which causes environmental and health issues, developing the lead-free electrocatalysts is greatly needed. Accordingly, we investigated the rate of lignin conversion and hydrogen production on different lead-free electrocatalysts developed in this study using a flow electrochemical reactor. Gas chromatography-mass spectrometry (GC-MS), high performance liquid chromatography (HPLC), and fourier transform infrared spectroscopy (FTIR) were employed to evaluate molecular weight distribution of lignin and characterize the functional groups.

References

[1] R. Ghahremani, J.A. Staser, Electrochemical oxidation of lignin for the production of value-added chemicals on Ni-Co bimetallic electrocatalysts, Holzforschung. 0 (2018). doi:10.1515/hf-2018-0041.
[2] T.K.F. Dier, D. Rauber, D. Durneata, R. Hempelmann, D.A. Volmer, Sustainable Electrochemical Depolymerization of Lignin in Reusable Ionic Liquids, Sci. Rep. 7 (2017) 5041. doi:10.1038/s41598-017-05316-x.
[3] P. Cai, H. Fan, S. Cao, J. Qi, S. Zhang, G. Li, Electrochemical conversion of corn stover lignin to biomass-based chemicals between Cu/NiMoCo cathode and Pb/PbO2 anode in alkali solution, Electrochimica Acta. 264 (2018) 128–139. doi:10.1016/j.electacta.2018.01.111.
Electrochemical Oxidation and Bond Cleavage of Lignin-Derived Model Compounds with Nanoparticle Catalysts
Authors: Ngo Ken , Baddour Frederick , Ruddy Daniel , Schaidle Joshua 
Published: February 2020

Electrochemistry offer an environmentally friendly approach to convert biomass or biomass derived material into valuable organic chemicals, petrochemical substitutes, and energy-intensive chemicals. Monomers could be generated by cleaving ether (C-O-C) linkages in lignin via thermal decomposition process such as reductive catalytic fraction (RCF). However, this process leaves behind a significant portion of soluble lignin oligomers with recalcitrant C-C linkages. Monomer yields from the RCF pathway are approaching theoretical limits based on ether bond cleavage. Therefore, with broader goal of improving lignin utilization within a biorefinery, we probed the electrocatalytic oxidation of model dimer compounds with C-C linkages representative of RCF oligomers.
Electrochemical studies offer several advantages including operation at low temperatures and pressures, applied potentials can be used to control reaction rates and selectivities, and renewable electricity can be used, thus lowering overall greenhouse gas emissions. According to previous studies, several metals such as nickel, cobalt, copper, and platinum can be used to build electrocatalysts for biomass conversion. Therefore, we have synthesized a series of low-cost nickel and molybdenum nanoparticle catalysts for the electrocatalytic oxidation of model compounds. Besides the high surface and high stability advantages of supported nanoparticles in general, these candidates exhibit interesting catalytic activities resembling that of noble metal catalysts such as platinum in oxygen reduction reaction (ORR) which could also be beneficial in bond cleavage reactions in biomass or biomass derived material.
The focus of this talk will be on the electrochemical studies of the selected nanoparticle catalysts toward C-C bond cleavage in RCF dimer model compounds. The results from the studies also lead to some insights we may be able to use to guide the future development of electro-oxidation of RCF oil/ biomass stream. Besides metallic, phosphide and carbide nanoparticles on carbon support, metal foils were also tested and were used as a comparison. Notably, a MoC catalyst on carbon support showed C-C and C-O bond cleavage activities in aqueous alcoholic solution with sodium hydroxide as the electrolyte.
Understanding Metal Structure Sensitivity during the Electrocatalytic Hydrogenation and Oxidation of Biomass-Derived Molecules at Normal Temperature and Pressure
Authors: Lopez Ruiz Juan A , Sanyal Udishnu , Koh Katherine , Qiu Yang , Andrews Evan , Nguyen Manh-Thuong , Karkamkar Abhijeet , Derewinski Miroslaw , Rousseau Roger , Gutiérrez Tinoco Oliver Y , Holladay Jamelyn 
Published: February 2020

In recent years there has been growing interest in using electrochemical methods for the upgrading of biomass-derived molecules for the formation of biofuels. Conventional upgrading processes require moderate temperatures between 433 and 678 K, pressures of 14,000 kPa, and external sources of dihydrogen for the stabilization and formation of biofuels. However, the same reaction can be performed using electrochemical reactors and much lower temperatures and pressures (293 K and 101 kPa) and with no supplied dihydrogen.
In this work, we evaluate the use of Pd, Pt, Rh, and Cu-based heterogeneous electrocatalysts for the electrocatalytic hydrogenation (ECH) and oxidation (ECO) of organic molecules present in biocrude. In particular, we studied the effect of electrolyte composition, half-cell (WvR) potential, and metal particle size on the Faradaic efficiency (FE) and catalytic activity (TOFECH and TOFECO) for different bio-oil derived-molecules such as aldehydes, ketones, phenolics, and carboxylic acids. Our results show that whereas the reduction of aldehydes and ketones into alcohols can be achieved electrocatalytically at normal temperature and pressure, carboxylic acids cannot be reduced. However, carboxylic acids can be oxidized to alcohols, olefins, and ketones via Kolbe and non-Kolbe mechanism. Further, we observed there the TOF and FE depend on metal, fractional exposure, substrate concentration and WvR potentials. For example, as shown in Figure 1, the FE and TOFECH are the highest when using Pd electrodes with low Pd weight loading (and small metal particle size). The FE and TOFECH decreases as the Pd weight loading (and particle size) increases. Eley-Rideal-type kinetics were used to understand the structure sensitivity of the Pd electrocatalysts and revealed that it is related to changes in rate constants and substrate surface coverage. That is, small Pd nanoparticles have higher ECH rate constant and higher benzaldehyde surface coverage compared to large Pd particles. Structure sensitivity was also observed on Pt and Rh-based electrocatalysts, but with opposite trend. That is, large Pt and Rh nanoparticles were more active than small nanoparticles. Cu-based catalysts were structure insensitive.

Figure 1. TOFECH (A) and Faradaic Efficiency (B) as a function of WvR potentials under normal conditions for the benzaldehyde ECH to benzyl alcohol. Catalysts with different Pd loadings were used where represents 0.05wt% Pd/CF, represents 0.10wt% Pd/CF, represents 0.50wt% Pd/CF, represents 1.0wt% Pd/CF, and represents 4.0wt% Pd/CF.

Figure 1