bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) HydroGEN Benchmarking: Developing Best Practices for Water Splitting Technologies
Authors: Ayers Katherine E. , Gross Karl 
Published: February 2020

The need for renewable sources of hydrogen is increasing rapidly based on global goals for decarbonization. Interest and investment has also increased with the advent of the Hydrogen Council and the DOE H2@Scale initiative. There are several pathways which could eventually be part of the overall mix, but are currently at different maturities and have different challenges. Low cost renewable energy provides a potential pathway for low temperature electrolysis to make a large impact in the short term, while high temperature baseload such as nuclear matches well with high temperature electrolysis based on solid oxide technology. Photoelectrochemcal and solar thermal chemical water splitting are earlier stage technologies, but could be viable in the long term especially in areas without current infrastructure, if the materials targets can be achieved and manufacturing capability is developed. In the nearer term, understanding of these challenges can also provide valuable perspective for the more mature pathways.
In any of these technologies, appropriate comparisons of test results is important to measure overall progress in the field and identify promising directions, as well as to provide credibility to published results. The DOE Fuel Cell Technologies Office previously funded the development of a detailed reference guide of common methodologies, protocols, and important limitations for measuring critical performance properties of advanced hydrogen storage materials, which has served as a resource to the hydrogen storage materials development community to aid in clearly communicating the relevant performance properties of new materials as they are discovered and tested. The project was coordinated with the IEA and involved 46 co-authors and contributors from 9 countries. The final documents are available to the public on-line: https://www.energy.gov/eere/fuelcells/downloads/recommended-best-practices-characterization-storage-properties-hydrogen-0

A similar effort is now underway for water splitting technologies, framed by questionnaires distributed to the community, frameworks for materials and device testing, and workshops and discussions for feedback. A series of protocols is being drafted to provide easy to follow procedures for materials characterization. The team is also identifying gaps in methods and materials for possible development, and drafting technology roadmaps to highlight research needs. This talk will describe the success of the storage effort, and status for the water splitting benchmarking project.
(Invited) Multiscale Modeling of Reactive Interfaces in Support of the DOE Energy Materials Network
Authors: Wood Brandon C. 
Published: February 2020

Energy storage and conversion devices rely on chemical process occurring at solid-gas, solid-liquid, and solid-solid interfaces. Probing behavior of these interfaces under operating conditions presents significant challenges; however, predictive modeling offers an opportunity for providing key insights into interface chemistry, particularly when operating in tandem with high-fidelity experimental characterization techniques.
Within the DOE Hydrogen Materials—Advanced Research Consortium (HyMARC) and the HydroGEN Advanced Water Splitting Materials Consortium, we are using multiscale models to understand properties of reactive interfaces for the production and storage of hydrogen. I will provide an overview of our materials modeling strategy within these consortia, ranging from first-principles calculations of interface chemistry to continuum methods for microstructure-level properties. I will then review some of our recent activities for simulating thermodynamic and kinetic properties of hydrogen-related materials. Specific examples will be given of how these computational models have helped to elucidate mechanisms of interface chemical reactions, the formation of new phases, and the impact of solid-state interfaces on key reaction pathways. I will also show how simulations have been combined with experimental probes to improve models and obtain new understanding of materials interfaces under operating conditions. Finally, I will discuss how this understanding is being used to guide new strategies for improving materials functionality for hydrogen storage and production.
This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
(Invited) Development of a Multiscale Approach for Modeling Fuel Cell Electrodes
Authors: Pant Lalit M. , Chowdhury Anamika , Weber Adam Z. 
Published: February 2020

Porous electrodes form a critical part of electrochemical energy systems such as polymer electrolyte fuel cells (PEFCs). In order to improve their performance and reduce cost, novel designs for porous electrodes are being envisioned, e.g., non-PGM catalyst layers, ultra-thin Pt/Pt-Ni based catalyst layers, or NSTF catalyst layers.1 These electrodes have features spanning multiple length scales: from nano-scale catalyst particles to micrometer thick catalyst layers; with meso-scale porous structure in between. In order to understand the impact of these new designs on cell performance, a detailed understanding of the multi-scale structure is required. Furthermore, the physical processes at each length scale must be understood and up-scaled in order to evaluate the macro-scale cell performance.
The aim of this work is to develop multi-scale models which can account for the effect of micro and meso scale structure on macro-scale performance. Figure 1 shows a schematic of the multi-scale approach for modeling PEM fuel cells. This approach can be used for conventional Pt based electrodes, or for non-PGM based electrodes where large catalyst particles induce significant local flooding and reactant losses. The microstructure is generated using stochastic techniques.2,3 The crucial micro-structural properties such as pore sizes, ECSA, phase distributions are obtained using physical characterization methods such as imaging, Cyclic voltammetry, and BET. The generated microstructures will be used to simulate pore-level physics, where local transport, and reactions will be modeled. The pore scale performance will then be upscaled and used with macro-scale models to simulate system level performance.
To analyze critical parameters for fuel cell performance, sensitivity studies will be performed using the macro-scale model. The aim is to identify parameters which affect the cell performance significantly and therefore must be measured accurately and provide a way to optimize cell performance. Apart from macro-scale parameters, the multi-scale sensitivity study can also be used to optimize ionomer and catalyst distribution.

Acknowledgements

The work is funded under the Fuel Cell Performance and Durability Consortium (FC-PAD), by the Fuel Cell Technologies Office (FCTO), Office of Energy Efficiency and Renewable Energy (EERE), of the U.S. Department of Energy under contract number DE-AC02-05CH11231.

References

P. K. Sinha, W. Gu, A. Kongkanand and E. Thompson, J. Electrochem. Soc., 158, B831 (2011).

F. C. Cetinbas, R. K. Ahluwalia, N. N. Kariuki and D. J. Myers, J. Electrochem. Soc., 165, F1051 (2018).

L. M. Pant, S. K. Mitra and M. Secanell, Phys. Rev. E, 92, 063303 (2015).

Figure 1
Analysis of Energy-Structure Relationship for Ce3+ in Garnet-Type Oxides Based on First-Principles Calculations
Authors: Ogasawara Kazuyoshi 
Published: February 2020

The 4f-5d transitions of Ce3+ in crystals are utilized for various optical materials such as solid-state lasers, scintillators, and phosphors. Since the 4f-5d transition energy of Ce3+ in crystals strongly depends on the local structure around Ce3+, it is important to understand the relationship between the energy levels and the local structure for theoretical design of novel optical materials based on Ce3+. In order to control the local structure, garnet-type oxides are useful as host crystals since there are three types of cation sites and the local structure around the impurity Ce3+ ion can be modified widely by cation substitution. In garnet-type oxides, Ce3+ usually occupies the dodecahedral site with D2 symmetry. The arrangement of eight nearest neighbor O2- ions can be understood as interpenetrating two tetrahedrons. Therefore, the geometry of CeO8 cluster can be specified by six structural parameters corresponding to the coordinates of two representative ligand positions. However, investigation of the energy-structure relationship depending on six structural parameters is not straightforward.
In this work, in order to visualize the energy-structure relationship of Ce3+ occupying the dodecahedral site in garnet-type oxides, two-dimensional energy maps were constructed by performing first-principles relativistic molecular orbital calculations for a series of CeO8 clusters constructed by changing two selected structural parameters. The 4f-5d transition energies of Ce3+ for these clusters were calculated based on the Slater’s transition state method. Then the relationship between the 4f-5d transition energy and the local structure depending on the six structural parameters was clarified by the combination of these energy maps.
Enrichment in Methane Content in Biogas By External Voltage Supply
Authors: Poudyal Pranita , Prajapati Bikram , Bajracharya Suman , Joshi Jarina 
Published: February 2020

The increment in the methane content has a major role to broaden the application of biogas. Enhancement of the methane-generating metabolism of microorganisms known as methanogens is required to increase the methane production. Research has shown that methanogens can use supplied voltage to acquire the electrons for the production of methane from CO2. In this process, methanogens reduce CO2 to CH4 utilizing electrons from externally supplied voltage on integrating with anaerobic digestion. Microbial electrochemical cells (MEC) was developed employing biocompatible fibrous graphite electrodes. Cow manure was assessed for the anaerobic digestion combined with MEC. The objectives of the study were to use manure waste and to enrich methane in biogas even at low temperature condition. The biogas produced contains mainly methane, hydrogen sulphide and carbon dioxide. The maximum gas production was at 37oC. However, biogas could be produced at 18oC with supply of 2V external power. There was found 65 times increment in biogas production with external power supply at 18oC. Besides methanogens, two other bacterial species identified were Serratia liquefaciens and Zoballella taiwanensis respectively.
Keywords: Methane, biogas, methanogens, voltage, anaerobic digestion, microbial ecology
Synthesis and Characterization of Osmium Redox Polymer Mediators for Type II Biosensors
Authors: Calhoun Margaret C , Stachurski Christopher , Gizzie Evan A. , Daniel Aaron W. , Cliffel David E. 
Published: February 2020

Electrochemical sensors that utilize enzymes are a sensitive, inexpensive means of detecting biologically relevant analytes. These sensors are further categorized based on their construction and method of signal transport.1 Type I sensors consist of a crosslinked enzyme on an electrode surface, which are subject to interference from byproducts and other biological analytes. However, type II sensors alleviate this problem with the addition of a redox polymer layer, to assist in signal transportation, thus minimizing interference. There are a growing number of Type II sensors in the literature, however few are commercially available and typically suffer from poor structural and optical characterization.
Previously, an osmium-loaded poly(vinylimidazole) polymer (Os-PVI) was synthesized in order to avoid acetaminophen interference in enzyme sensor testing with successful results, yielding a type II sensor.2, 3 Given the success of the polymer, and the potential applications of the polymer for both enzyme and eletrogenerated-chemiluminescent sensors, it was important for Os-PVI to be properly characterized. Using previous literature, the two precursors Os(bpy)2Cl2 and poly(vinylimidazole) were synthesized. However, attempts at replication lead to the synthesis of an unknown osmium precursor. When coupled to PVI, a new osmium polymer was synthesized with new fluorescent and redox properties that did not match with the original Os-PVI polymer. All precursors and osmium polymers were characterized with 1H NMR, fluorescence, mass spectrometry, and cyclic voltammetry in order to provide a better understanding of these compounds and assist in the building of new sensors.

Wang, J.; Ju, H.; Zhang, X., Electrochemical Sensors, Biosensors and Their Biomedical Applications. Academic Press: Amsterdam, 2008; Vol. 1st ed.

Ohara, T. J.; Rajagopalan, R.; Heller, A., "Wired" Enzyme Electrodes for Amperometric Determination of Glucose or Lactate in the Presence of Interfering Substances. 1994,
66 (15), 2451-2457.

Forster, R. J.; Vos, J. G., Synthesis, characterization, and properties of a series of osmium- and ruthenium-containing metallopolymers. Macromolecules
1990,
23 (20), 4372-4377.
Electrochemical Behavior of Selenophene in Quaternary Ammonium and Phosphonium Based Ionic Liquids
Authors: Yasugi Noriaki , Tsunashima Katsuhiko , Higashi Toshikazu , Sakaguchi Yuki , Yamada Hirohisa , Matsumiya Masahiko 
Published: February 2020

Room-temperature ionic liquids (RTILs) have been regarded as potential electrolytic media for electropolymerization processes.1 Many kinds of RTILs have been investigated for the electropolymerizations. For example, we have reported that a bis(fluorosulfonyl)amide (FSA) anion based imidazolium ionic liquid promoted the electropolymerization reaction of pyrrole and the anion doping into the polymerized film, improving the conductivity of the film.2 We also have applied the phosphonium based RTILs to the electropolymerization of pyrrole and thiophene, investigating the influence of the phosphonium RTILs on the polymerized film properties.3 However, electrosynthesis of polyselenophene in phosphonium RTILs has not been examined. In this work, we report the electropolymerization of selenophene in triethylpentylphosphonium FSA (P2225-FSA) (Fig. 1) and the effect of the phosphonium RTIL on the polyselenophene film properties.
P2225-FSA was prepared according to the procedure we have previously reported,4 and dried under high vacuum at 80°C for 6 h before use. The electropolymerization of selenophene in P2225-FSA was carried out by cyclic voltammetry (CV) method using a three-electrode cell equipped with a working electrode of platinum or transparent glass electrode and an IL-based Ag/Ag+ reference electrode.
Figure 2 showed the cyclic voltammograms for the electropolymerization of selenophene in P2225-FSA. In the first cycle, the oxidation peak current value of about 0.2 mA was shown around +1.7 V vs Ag/Ag+, and the current decayed with each cycle. This closely resembles the electrochemical behavior observed in CVs using π-conjugated aromatic compounds such as pyrrole and thiophene as substrates. 3 After 10 cycles, a black thin film was grown on the surface of the working electrode, and the oxidation current observed in this CV seems to be due to the electropolymerization reaction of selenophene. Furthermore, we will discuss the comparison between the behaviors in various quaternary onium based ionic liquids from the viewpoint of the morphology of the polymer film grown on the working electrode.
References

K. Sekiguchi, et al, J. Electroanal. Chem.
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1, 557 (2003).

K. Tsunashima, et al, ECS Electrochem. Lett., 3, G1 (2014).

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Figure 1
A Kinetic Analysis of the CO Electro-Oxidation Reaction on Pt Bimetallics: Understanding the Interplay of Bifunctional and Electronic Effects
Authors: Baz Adam , Holewinski Adam 
Published: February 2020

The CO electro-oxidation reaction has been one of the most thoroughly studied reaction mechanisms in electrocatalysis, mostly due to its role as a model reaction for the oxidation of larger organics like methanol and ethanol, each of which have important renewable energy applications in direct alcohol fuel cells. Bimetallics of Pt-M (where M is an oxophilic modifier such as Ru or Sn) have been shown extensively to have improved CO tolerance compared to pure Pt. The reason for this enhancement is often attributed to some combination of bifunctional (oxophilic metal provides OH to remove poisoning CO on Pt) and electronic (oxophilic metal weakens the CO binding strength on the Pt sites) effects. However, it has been difficult to determine the extent to which these different effects are operative in a given system.
In this work, we perform a kinetic analysis of the CO electro-oxidation reaction in order to elucidate the roles of bifunctional and electronic effects. We look specifically at the classic Pt-Ru bimetallic system, and determine that the rates of bifunctional coupling are generally lower than the rates of coupling on Pt sites electronically modified by Ru. This indicates that, at least for the Pt-Ru system, the electronic effects that weaken CO binding on Pt are more operative than the bifunctional effect. This implies that that the prospects for bifunctional gains in general may be more limited than once thought, and that a more rational design parameter for bimetallic materials may be the electronic effects between the two components.
Operando Pattern-Enhanced Resonant Scattering for Sub-Nm Interfacial “Spectromicroscopy”­ of Energy Materials
Authors: Wang Cheng , Cordova Isvar A. , Freychet Guillaume , Kilcoyne David , Xu Wei , Hexemer Alexander 
Published: February 2020

The advent of highly precise nanofaborication tools has enabled the development of the next generation of mesoscale energy materials, but it requires concomitant progress in the characterization techniques used to address the new challenges and questions inherent to their interfacial behavior at this scale.
We present a powerful, yet simple, patterning approach for interface characterization that takes advantage of the physical processes intrinsic to small angle resonant X-ray scattering in order to 1) decouple the bulk from the interface scattering signal, 2) enhance the strength of said signal, and 3) collect site-specific absorption spectra. In addition to the reconstructing the thickness and shape of the interfacial layer, changes in scattering contrast as a function of energy may be tracked in order to produce a full site-specific x-ray absorption spectrum that can identify small, yet vital, fluctuations in local chemistry. In addition, unlike nm-resolution microscopic techniques, the highly sensitive spatio-chemical information obtained via scattering processes doesn't require a highly focused beam whose flux is more likely to inadvertently affect the chemical reactions at the interface, thus making it more amenable to in-situ/operando characterization.
In this presentation, we demonstrate the ability to selectively probe the interfacial regions of inorganic materials used throughout the fields of energy conversion and storage with nm-scale precision. we leverage a newly-developed in-situ cell for gas/liquid flow and electrical biasing that is compatible with many "soft" and "tender" X-ray beamlines and use it conduct an operando study of Ni/Ni(OH)2 core/shell system undergoing cycling under aqueous conditions. We find that the pattern-enhanced RSoXS approach enables the monitoring of the interfacial region's local morphology as it is electrochemically charged and discharged with millisecond time resolution and sub-nm precision, thus shedding quantifiable insights into the kinetics of the OH- intercalation process. In addition, the Ni L-edge XAS from the metal bulk region that is directly decoupled from that from the hydroxide surface is consistent with previously reported spectra. We will also reveal preliminary results showing how this technique may be applicable to study a variety of interfaces, even if the junction of interest is buried under another solid, liquid, or gas material. Finally, we describe the practical considerations of this characterization technique as it is extended to other material systems, patterning designs, sources, etc.
(Invited) Thin Layer Sonoelectrochemistry: Impacts on Slow Electron Transfer Kinetics without Visible Cavitation
Authors: Duda Chester G , Parke Brenna , Leddy Johna 
Published: February 2020

Sonochemistry and sonoelectrochemistry are typically undertaken in a bulk fluid with sonication of sufficient intensity to generate visible cavitation. Sonoelectrochemistry was undertaken in a thin layer of fluid with a quartz crystal oscillator. In the thin layer configuration, no cavitation is visible and mass transport is not impacted, but impacts on electron transfer kinetics are observed.
Because there is no visible cavitation, cyclic voltammetric responses typical of a quiescent electrolyte are observed. From the voltammograms for species that undergo rapid heterogeneous electron transfer such as outer sphere Ru(bpy)₃²⁺⇌Ru(bpy)₃³⁺+e, voltammetric morphology is unchanged on sonication of a thin layer of fluid. For Fe³+e⇌ Fe² that undergoes quasireversible (slower) electron transfer under cyclic voltammetric perturbation, sonication in a thin layer is found to increase the rate of heterogeneous electron transfer by roughly an order of magnitude.
Sonoelectrochemical catalysis for inherently slow heterogeneous electron transfer processes is generated and observed in a thin layer of electrolyte. In the experiments reported here, the fluid layer was less than the wavelength of sonication. The aqueous electrolyte contains redox species and acid. Experiments were undertaken at a platinum wire electrode using a 41 kHz quartz crystal oscillator. For the same experimental conditions, no impact on the electron transfer reversible Ru(bpy)₃²⁺ was observed. All data were collected at a fixed frequency; impacts varied with oscillator intensity.
As with many sonoelectrochemical experiments, subtle variation in experimental parameters complicate generation of reproducible results. Here, data generated by two different experimentalists yield similar outcomes. Best operating conditions differed slightly for the two experimentalists but the pattern of increased interfacial electron transfer rates for iron on sonication was found by both.
Reference
[1] Johna Leddy, Chester G. Duda, Jacob Lyon, and William J. Leddy III, "Thin Layer Sonoelectrochemistry and Sonoelectrochemistry Devices and Methods," published 28 May 2015 as US Patent Application 20150147594 A1.