bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Evaluation of Steam Splitting (OER) Kinetics in Praseodymium-Based Perovskite Thin Film Electrodes for Efficient Intermediate-Temperature Water Electrolysis
Authors: Lee Jongmin , Perry Nicola H 
Published: July 2022

Water electrolysis at high temperatures (> 600 ˚C) provides both kinetic (no precious metals) and thermodynamic (lower voltage requirement) benefits for hydrogen generation. However, recently steam electrolysis at intermediate temperatures (300 - 600 ˚C) has attracted attention, given potentially faster startup times, ready access to waste heat, and mitigation of some degradation modes, while maintaining some of the high temperature benefits. Intermediate-temperature electrolysis can be accomplished with protonic ceramic electrolysis cells (PCECs), for which a primary challenge is the need for efficient, chemically stable, and long-term durable oxygen/steam electrodes. Electrode material candidates tend to be perovskite-based oxides that must be triple conductors, enabling transfer of oxide ions, protons, and electronic species for PCECs. While Barium (Ba) containing perovskite (ABO3) oxygen electrodes are an active focus due to their low hydration enthalpies enabled by the basicity of Ba, their poor long-term stability and non-optimized catalytic activity hinder the practical deployment of PCECs. Additionally, segregation of large cations (e.g., Ba, Sr) often takes place on electrode surfaces, which further hinders their catalytic performance and long-term stability. Thus, we have been investigating synthesis and performance of lower-Ba or Ba-free oxygen/steam electrodes and relating these to the evolution of the surface chemistry during operation.
In this work, we fabricated Pr-based perovskite oxides, including Pr(Ga,Mg)O3-x, Ba(Pr,Y)O3-x, and others, as thin films with well-defined geometries and surface areas using pulsed laser deposition and compared their performance to the standard Ba(Co,Zr,Fe,Y)O3-x. Considering the multiple valence states (3+, 4+) of Pr and its large size, which may lead to surface segregation, the inclusion of Pr, or even replacement of Ba with Pr, is hypothesized to benefit catalytic activity and stability. We examined the surface water splitting/ hydrogenation coefficients (k-values) using electrical conductivity relaxation with pH2O steps, as a function of time and gas atmosphere. Further investigations of the role of crystalline quality, composition, and thickness have been made to understand the factors controlling the thin film electrode activity and stability. Our results of quantitative k-values on well-defined surfaces can guide design of high performance steam/oxygen electrodes and understanding of degradation mechanisms impacting performance of PCECs.
High-Pressure PEMWE Stack and System Characterization
Authors: Hancke Ragnhild , Bujlo Piotr , Holm Thomas , Ulleberg Øystein 
Published: July 2022

As the urgency to decarbonize the industry and transport sector intensifies, renewable energy-based hydrogen production via advanced low temperature water electrolysis is attracting increased interest. Proton exchange membrane water electrolysers (PEMWE) offer several benefits over the more mature alkaline water electrolysis technology, including its load-following capability and the ability to operate at higher pressures. The latter is important because significant benefits can be harvested by adopting systems operating at pressure-levels compatible with the end use applications and thereby render the mechanical compressor redundant. At IFE we have developed a methodology which encompasses detailed energy- and techno-economic calculations of high-pressure systems, and a comparison between high-pressure electrolysis and state-of-the-art electrolysis at 30 bar in combination with a compressor has been carried out. Here, direct pressurization to 80 and 200 bar (relevant for, e.g., methanol and ammonia production) was found to be economically viable.
To realize high-pressure H2 generation systems, many challenges related to system operability, efficiency and safety needs to be addressed. As part of the national infrastructure “The Norwegian Fuel Cell and Hydrogen Centre”, Institute for Energy Technology (IFE) has installed a flexible PEM water electrolyzer system platform for testing of small-scale prototype electrolyzers up to 33 kW and 200 bar differential pressure. The test rig is integrated with a sophisticated power conditioning system which consists of three custom-built DC/DC-converters (for PEMWE, PEMFC, and Li-ion battery systems), all coupled to the same DC-bus. This configuration makes it possible to test different hybrid electric topologies and to emulate different loads (e.g., grid load profiles, wind generation). This one-of-a-kind high-pressure PEMWE test facility at IFE is well suited to study performances of next-generation PEMWE stacks and systems, and to tailor and test control strategies that safeguards the system and maximizes efficiency and durability
The test rig has been commissioned with a prototype high-pressure stack with a production capacity of 2 Nm3/h (Nel Hydrogen), and the identified economically viable pressure range of 80-200 bar has been the main target for an experimental test campaign. The experimental results are presented from stack testing including polarization curves and EIS data as a function of temperature, pressure and current density. The results are discussed in relation to the techno-economic model, in order to identify pathways towards more efficient hydrogen production.

Figure 1
Understanding Proton Exchange Membrane Water Electrolyzer Hydrogen Crossover Mitigation in Reactive Spray Deposition Technology Fabricated Dual Recombination Layers through Distribution of Relaxation Times Analysis
Authors: Gado Alanna M. , Ouimet Ryan J. , Bliznakov Stoyan , Bonville Leonard J. , Maric Radenka 
Published: July 2022

Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology to produce zero-carbon emission, renewable, high-purity hydrogen. [1] There is a need to reduce capital cost while improving performance for the progression of widespread development. The crossover of hydrogen from the cathode into the anode not only restricts cell performance, but also poses a safety hazard, as the crossover reaches the lower explosive limit of hydrogen in oxygen. [2] Previous work has been conducted on the fabrication and testing of Pt recombination layers in PEMWEs. The addition of the Pt recombination layer has proven to be an effective mitigation strategy for hydrogen crossover while improving performance. [3, 4] Further investigation is needed to understand the mechanisms of the Pt recombination layer.
In this work, reactive spray deposition technology (RSDT) was used to deposit two Pt recombination layers separated by a membrane. Testing of a single cell 25 cm2 PEMWE was conducted. Polarization analysis, electrochemical impedance spectroscopy, and distribution of relaxation times were used to investigate the cell performance. Results show good cell performance and hydrogen crossover reduction, as well as insight to the mechanisms of the chemical reactions that occur on the dual recombination layer.

References

[1] Aricò, A. S., Siracusano, S., Briguglio, N., Baglio, V., Di Blasi, A., & Antonucci, V. (2012). Polymer electrolyte membrane water electrolysis: Status of technologies and potential applications in combination with renewable power sources. Journal of Applied Electrochemistry, 43(2), 107–118. https://doi.org/10.1007/s10800-012-0490-5
[2] Schalenbach, M., Carmo, M., Fritz, D, L., Mergel, J., Stolten, D. Pressurized PEM water electrolysis: Efficiency and gas crossover, International Journal of Hydrogen Energy, 38(35), (2013), 14921-14933.
[3] Klose, C., Trinke, P., Bohm, T., Bensmann, B., Vierrath, S., Hanke-Rauschenbach, R., Thiele, S. Membrane Interlayer with Pt Recombination Particles for Reduction of the Anodic Hydrogen Content in PEM Water Electrolysis, Journal of Electrochemical Society, 165(16), (2018), F1271-F1277.
[4] Mirshekari, G., Ouimet, R., Zeng, Z., Yu, H., Bliznakov, S., Bonville, L., Niedzwiecki, A., Capuano, C., Ayers, K., Maric, R. High-performance and cost-effective membrane electrode assemblies for advanced proton exchange membrane water electrolyzers: Long-term durability assessment. International Journal of Hydrogen Energy, Volume 46, Issue 2, 2021, Pages 1526-1539, ISSN 0360-3199, https://doi.org/10.1016/j.ijhydene.2020.10.112.
(Invited) Electrochemical Pumping for Hydrogen Storage and Distribution in the Natural Gas Pipeline
Authors: Arges Christopher G. , Venugopalan Gokul , Bhattacharya Deepra 
Published: July 2022

Over the next decade, the production and use of hydrogen in various sectors of the global economy is anticipated to grow significantly. It is an already important feedstock in the production of ammonia and desulfurization of fuels in addition to being used in metals refining and as a coolant in thermal electric power plants. More recently, hydrogen is being considered for long-term seasonal energy storage for energy derived from renewables like solar and wind. To alleviate the severe costs of building out completely new infrastructure, the U.S. natural gas pipeline represents an enticing proposition for hydrogen storage and a potential distribution network from centralized production facilities. Embrittlement concerns of the pipeline with hydrogen limit the hydrogen partial pressure/concentration of hydrogen to be stored. Because many end use applications often require high purity hydrogen, it is necessary to separate/de-blend hydrogen from natural gas and compress it at the point-of-use.
This talk presents high-temperature polymer electrolyte membrane (HT-PEM) electrochemical hydrogen pumps for separating hydrogen from gas mixtures. Hydrogen purification to +99% from syngas (25mol% hydrogen and 40mol% carbon monoxide (CO)) at 1 A cm-2 and cell voltage of 0.4 V with an electrochemical hydrogen pump was demonstrated. About 90% of hydrogen used in the United States today derives from steam-reformed natural gas that contains large concentrations of CO – which is a potent platinum electrocatalyst poison at temperatures below 100 °C. The hydrogen purification from syngas was possible with an electrochemical hydrogen pump operated at 220 °C and by using: i.) an ion pair HT-PEM that exploits electrostatic interactions to prevent phosphoric acid leaching at elevated temperatures from the membrane matrix and in the presence of water and ii.) a phosphonic acid ionomer electrode binder. The membrane electrode assembly (MEA) with the said materials and platinum on carbon (Pt/C) electrocatalyst was also effective for purifying hydrogen from other types of reformed hydrocarbons with different CO and hydrogen concentrations. Unexpectedly, operating the HT-PEM hydrogen pump at 220 °C minimized CO impact on cell polarization. At this temperature, cell polarization was governed by the hydrogen concentration in the gas feed. These observations motivate future work to develop new electrodes and electrode binders that can extract, purify, and compress hydrogen with feed streams that have low hydrogen content and contain other constituents in natural gas (methane, ethane, t-butyl mercaptan, etc).
Biobased Polymer Synthesis from Vanillin in an Electrochemical Flow Reactor
Authors: Kunkel Robin , Fath Maximilian , Schmiedl Detlef , Müller Dominik , Simmat Fabian , Schmidt Volkmar M , Tübke Jens 
Published: July 2022

The development of new synthesis routes for the production of biobased polymers is an urgent matter in the context of climate change. One possible promising key intermediate is vanillin (4-hydroxy-3-methoxybenzaldehyde), as it is one of a few aromatic biobased compounds, which is already available on an industrial scale. Vanillin can be produced sustainably with potential yields of up to 7% from lignin, a side product in the paper and pulp industry with amounts of over 107 tons per year. Therefore, much effort was spent from the scientific community for the preparation of a broad range of new vanillin-based polymers [1].
One attractive synthesis route is the electrochemical reductive production of polyvanillin, a total vanillin-based polymer. Polyvanillin is synthesized by electrochemical pinacolization of divanillin (5-5´bisvanillyl), which is easily available by enzymatic conversion of vanillin with horseradish peroxidase and hydrogen peroxide (Scheme 1). Recent studies from others [2] as well as from our working group [3] showed the feasibility of this synthesis route and investigated the impact of electrochemical reaction parameters in batch cells.
As a next step, we here transferred the electrochemical reduction of divanillin to polyvanillin from an electrochemical batch reactor into a divided plan parallel flow reactor in recycle mode. The reductive conversion of the aldehyde groups was monitored by an on-line UV-Vis setup and the molecular weight increase was followed by size exclusion chromatography. Further, 2D-NMR (HSQC, 1H/13C) was used to identify structural features of the produced polyvanillin samples. The impacts of different electrochemical impact parameters, such as applied charge, current density, flow velocity and concentration were investigated. Current densities of over 50 mA cm-2 were readily achievable and weight-averaged molecular weights up to 4300 g mol-1 were reached.
This study shows an innovative electrochemical approach for the synthesis of new biobased polymers in an electrochemical flow reactor offering a total green process.

References

[1] M. Fache, B. Boutevin, S. Caillol, Eur. Polym. J. 2015, 68, 488-502.
[2] A. S. Amarasekara, B. Wiredu, A. Razzaq, Green Chem.
2012, 14, 2395–2397.
[3] R. Kunkel, V.M. Schmidt, C. Cremers, D. Müller, D. Schmiedl, J. Tübke, RSC Adv.
2021, 11, 8970-8985.

Figure 1
(Digital Presentation) Electrochemical Peptide Synthesis Utilizing Triphenylphosphine (Ph3P) in a Biphasic System
Authors: Nagahara Shingo , Okada Yohei , Kitano Yoshikazu , Chiba Kazuhiro 
Published: July 2022

Recently, peptides have been recognized as candidates for medium molecular medicines, which refers to pharmaceutical compounds whose molecular weights are roughly in the 1000 to 5000 range. This class of medicines has more specificity and fewer side effects than conventional small molecular medicines. However, an amount of waste derived from coupling reagents is regarded as a serious drawback of peptide synthesis from a green chemistry viewpoint.1

To address this issue, we have developed an electrochemical peptide synthesis utilizing triphenylphosphine (Ph3P) in a biphasic system (MeCN-c-Hex).2 Anodic oxidation of Ph3P generates a phosphine radical cation, which serves as the coupling reagent to activate carboxylic acids followed by peptide bond formation and production of triphenylphosphine oxide (Ph3PO) as a stoichiometric byproduct.3 Given that methods to reduce Ph3PO to Ph3P have been reported,4 Ph3P can be a recyclable byproduct unlike byproducts from typical coupling reagents.
In the optimized condition, we found that all canonical amino acids can be applied to electrochemical peptide bond formation and succeeded in the selective recovery of desired peptides and Ph3PO in combination with a soluble tag-assisted liquid-phase peptide synthesis. Moreover, a commercial peptide active pharmaceutical ingredient (API), leuprorelin, was successfully synthesized without the use of traditional coupling reagents.
Reference
1. M. C. Bryan, P. J. Dunn, D. Entwistle, F. Gallou, S. G. Koenig, J. D. Hayler, M. R. Hickey, S. Hughes, M. E. Kopach, G. Moine, P. Richardson, F. Roschangar, A. Steven and F. J. Weiberth, Green Chem., 2018, 20, 5082–5103.
2. S. Nagahara, Y. Okada, Y. Kitano, K. Chiba, Chem. Sci., 2021, 12, 12911–12917.
3. A. Palma, J. Cardenas and B. A. Frontana-Uribe, Green Chem., 2009, 11, 283–293.
4. D. Hérault, D. H. Nguyen, D. Nuel and G. Buono, Chem. Soc. Rev., 2015, 44, 2508–2528.

Figure 1
(Digital Presentation) Electrochemical Phosphonylation of π-Conjugated Polymers
Authors: Taniguchi Kohei , Kurioka Tomoyuki , Shida Naoki , Tomita Ikuyoshi , Inagi Shinsuke 
Published: July 2022

π-Conjugated polymers exhibit attractive optoelectronic properties because of their extended π-conjugation system along with main chains. Therefore, the introduction of functional groups into their main chains is a straightforward strategy to control their optoelectronic properties. In this context, post-functionalization is a practical methodology to install functional units. Among the post-functionalization methods, electrochemical post-functionalization is a promising fashion due to its outstanding abilities to transform aromatic C–H bonds of π-conjugated polymers into various functional units.1) For example, anodic chlorination of poly(3-hexylthiophene) (P3HT) has been reported (Fig. 1 (a)).2) However, functional groups available for this post-functionalization remain limited to those derived from nucleophilic dopants such as a chloride ion.
Here, to expand the applicable functional groups for electrochemical post-functionalization, we attempted to develop the electrochemical phosphonylation of P3HT and poly(9,9-dioctylfluorene) (PFO) (Fig. 1 (b)). With the use of non-nucleophilic dopants and triethyl phosphite as neutral nucleophiles, we successfully achieved C–H phosphonylation of the main chains of these polymers. The introduced phosphonyl groups significantly affected the optoelectronic properties of P3HT and PFO. Particularly, phosphonylated PFO was found to show unique emitting properties.
References
1) S. Inagi, T. Fuchigami, Macromol. Rapid Commun., 2014, 35, 854.
2) S. Hayashi, S. Inagi, K. Hosaka, T. Fuchigami, Synth. Met., 2009, 159, 1792.

Figure 1
Engineering Extracellular Electron Transfer in
Escherichia coli
for Microbial Electrochemical Devices
Authors: Mouhib Mohammed , Reggente Melania , Li Lin , Schuergers Nils , Boghossian Ardemis Anoush 
Published: July 2022

Microbes hold great potential for green electrochemical synthesis as well as bio-electricity generation from organic waste. The key to the successful development of microbial electrochemical devices lies with the ability of the microbes to transport electrons across their outer membranes. These devices thus often rely on the use of microbes known as exoelectrogens, which include bacteria that have evolved metabolic pathways that enable extracellular electron transfer (EET) to solid substrates for cellular respiration. While exoelectrogens demonstrate facilitated electron transfer with the electrodes of these devices, natural exoelectrogens are often restricted to utilizing a narrow range of substrates that limits their versatility for processing different organic wastes and electrosynthesizing a rich diversity of high-value chemicals. By contrast, non-exoelectrogenic microbes such as
Escherichia coli
that lack efficient EET pathways are host to rich metabolic reaction networks that can be more readily tailored for various applications using synthetic biology.
In this work, we biologically engineer
E. coli
for enhanced EET. To this end, we expressed different combinations of proteins from the natural exoelectrogen
S. oneidensis
MR-1, as well as
E. coli
native proteins to optimize EET of the bioengineered strain. The bioengineered strains show significant improvements in electron transfer rates, as confirmed through colorimetric reduction assays of soluble electron acceptors and electrochemical characterizations following electrode reduction. The improved EET demonstrated in this work paves the way for increasing the efficiency of existing
E.

c

oli

-
based electrochemical devices while opening the doors to new applications that benefit from the broad chemical repertoire of these microbes.
Electrochemically-Driven Secondary Folding and Assembly of Peptides and Proteins
Authors: Masquelier Eloise , Liang Sheng-Ping , Levenson Robert , Malady Brandon , Sepunaru Lior , Morse Daniel , Gordon Michael 
Published: July 2022

Reversible electrochemical triggering of the random coil to α-helix conformational transition of polylysine, and secondary folding of reflectin A1, was accomplished at a Pt electrode at potentials < |1| V vs. Ag/AgCl. Direct electroreduction of the N-terminus vs. ε-amino groups in lysine (Lys) sidechains, imidazolium groups of histidine-containing reflectin A1, as well as hydronium reduction and electrolysis, could be easily distinguished and deconvolved using differential pulse voltammetry. Electrochemistry was coupled with in situ UV absorbance, circular dichroism, and dynamic light scattering to dynamically follow the evolution of secondary folding and assembly of polylysine and reflectin at different potentials. Isotope experiments in H2O vs. D2O unequivocally confirm that direct electroreduction of ε-NH3
+/ND3
+ groups in Lys sidechains, rather than electrochemically generated pH gradient-induced deprotonation, leads to subsequent α-helix formation in polylysine. The site-selective electrochemistry and optical methodologies to be presented herein can be generalized and extended to interrogate other protonation-sensitive biomolecular systems, and potentially provide access to early intermediates and control over the dynamic structural evolution of peptides and proteins.
[1] E. Masquelier, S.P. Liang, L. Sepunaru, D. E. Morse, M. J. Gordon, "Reversible Electrochemical Triggering and Optical Interrogation of Polylysine α-helix formation " Bioelectrochemistry vol. 144, p. 108007, 04/2020 2022, doi: 10.1016/j.bioelechem.2021.108007
[2] S. P. Liang, R. Levenson, B. Malady, M. J. Gordon, D. E. Morse, and L. Sepunaru, "Electrochemistry as a surrogate for protein phosphorylation: voltage-controlled assembly of reflectin A1," J R Soc Interface, vol. 17, no. 173, Dec 23 2020, doi: 10.1098/rsif.2020.0774.
Electrochemical Determination of Deoxynivalenol Using a Modified Glassy Carbon Electrode
Authors: Arteshi Kojabad Yaser , Lima Dhésmon , Mendes Hacke Ana Carolina , Kuss Sabine 
Published: July 2022

Mycotoxins are toxic secondary metabolites, produced by different types of molds. These substances cause economic losses and are considered as a global public health concern because the food supplies that are contaminated by mycotoxins are graded as unfit for consumption.1 Deoxynivalenol (DON), also called vomitoxin is one of the most representative mycotoxins which is mainly produced by Fusarium graminearum and Fusarium culmorum. DON commonly contaminates grains, such as corn, wheat and rice. DON has also been found to contribute to chronic disease development.2 The DON analysis for quality control purposes in grains commonly relies on expensive methods, such as GC-MS and HPLC or complex biosensors.3 These methods are used because of high sensitivity which makes it possible to detect trace amounts of DON in complex media. In this work, we propose an easy to use, rapid and cost-efficient detection method for DON based on modified glassy carbon electrodes (GCE). The electrochemical behavior of DON is studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. Limits of detection and quantification are determined. The performance of the sensor in spiked solutions and real samples is studied and compared with standard methods.

References

(1) Lee, H. J.; Ryu, D. Journal of Agricultural and Food Chemistry
2017, 65, 7034-7051.
(2) Pestka, J. J.; Smolinski, A. T. Journal of Toxicology and Environmental Health, Part B
2005, 8, 39-69.
(3) Tittlemier, S. A.; Brunkhorst, J.; Cramer, B.; DeRosa, M. C.; Lattanzio, V. M. T.; Malone, R.; Maragos, C.; Stranska, M.; Sumarah, M. W. World Mycotoxin Journal
2021, 14, 3-26.