bluuebunny/crossref_metadata_2025 huggingface dataset:
The Economics of High Temperature and Supercritical Water Electrolysis
Authors: Borsboom-Hanson Tory , Holm Thomas , Merida Walter
Published: July 2022

The growth of green energy in recent decades has resulted in increasing demand for hydrogen production with net-zero carbon emissions. Water electrolysis provides a solution to meet this demand, however it is currently too expensive to be cost competitive with hydrogen production methods of higher carbon intensity. High-temperatures and pressures can be leveraged to increase the energy efficiency of water electrolysis through kinetics and thermodynamic benefits, thereby reducing the overall cost of green hydrogen [1]. Additionally, performing water electrolysis directly at high pressures can help to avoid the added cost associated with gaseous hydrogen compression.

Little is known about the electrolysis of supercritical water and what benefits it might offer in terms of hydrogen cost reduction [2,3]. In this work, experimental data was collected for supercritical water electrolysis and used to build an electrochemical model suitable for use under those conditions. The results of this model, combined with components of a previously published technoeconomic model for a high-temperature and pressure water electrolysis plant [4], indicate that while supercritical water electrolysis is achievable it is not the most economically efficient choice for hydrogen production. High-temperature and pressure water electrolysis performed under optimal conditions can be used to achieve higher economic efficiency when compared with contemporary water electrolysis solutions. Finally, a thorough optimization of the model presents a grim picture for achieving the US Department of Energy’s $2 kgH2
-1 target through water electrolysis without government subsidy.

References:

[1] D. Todd, M. Schwager, W. Mérida, Thermodynamics of high-temperature, high-pressure water electrolysis, J. Power Sources. 269 (2014) 424–429. https://doi.org/10.1016/j.jpowsour.2014.06.144.

[2] H. Boll, E.. Franck, H. Weingärtner, Electrolysis of supercritical aqueous solutions at temperatures up to 800K and pressures up to 400MPa, J. Chem. Thermodyn. 35 (2003) 625–637. https://doi.org/10.1016/S0021-9614(02)00236-7.

[3] P.C. Ho, D.A. Palmer, Determination of ion association in dilute aqueous potassium chloride and potassium hydroxide solutions to 600°C and 300 MPa by electrical conductance measurements, J. Chem. Eng. Data. 43 (1998) 162–170. https://doi.org/10.1021/je970198b.

[4] T. Holm, T. Borsboom-Hanson, O.E. Herrera, W. Mérida, Hydrogen costs from water electrolysis at high temperature and pressure, Energy Convers. Manag. 237 (2021) 114106. https://doi.org/10.1016/j.enconman.2021.114106.

Figure 1
In-Situ Neutron Imaging and Pore Network Modeling of Counter Current Mass Transfer inside Porous Transport Layers Used for PEMWE
Authors: Altaf Haashir , Vidakovic-Koch Tanja , Tsotsas Evangelos , Vorhauer-Huget Nicole
Published: July 2022

The specific morphology of porous materials, as well as their physical properties, crucially affect their applications, e.g. their use in fuel cells, batteries, or electrolysers. A key point is the correlation of their transport properties with the spatially distributed pore structure. In polymer electrolyte membrane water electrolysers (PEMWE), the drainage of oxygen, counter-currently to the water supply inside the porous anode, can significantly control the performance of the system. More precisely, the temporal and spatially distributed oxygen coverage of the catalyst layer obstructs the water supply towards it, which can result in a decrease of reaction rate. At the same time affects the heterogeneous distribution of liquid water the temperature distribution inside porous electrodes. This can have a severe impact on the performance of the PEMWE as well as on the degradation of the catalyst material.

In the presented study, mathematical pore network modeling (PNM) was used to investigate the correlation of the porous transport layer (PTL) pore structure with the distribution of water (wetting) and oxygen (non-wetting). The pore network was reconstructed based on the information about porosity, pore size distribution, pore connectivity and pore shape, which were obtained from micro-computed tomography of commercial materials (Fig. 1a). Compared to existing macroscopic models, PNM is suitable for low capillary numbers, takes local wetting characteristics into account and resolves the invasion process at the pore scale. The quasi-static nature of the model provides an edge over other modelling techniques in terms of computational power and additionally the ease of implementation of locally distributed properties. With the help of PNM, it was studied how a change of structure, i.e. the spatial grading of the pore size distribution and porosity, affects the local oxygen and water distribution, as well as the transport properties. This phenomenon was also analyzed experimentally by the use of a non-electrochemical aluminum cell (Fig. 1b and 1c) which was employed in an in-situ imaging setup installed at ILL, Grenoble, France. The recorded water saturations can be compared to the simulation results with the purpose of model validation and further model development. The outcomes of this study can be useful for the development of structural grading strategies with the target of improved transport properties for the efficient removal of the reactant oxygen and the homogeneous distribution of water.

Figure 1
Operando Study of MEA-Based CO2 Electrolyser over Copper Based Gas Diffusion Electrodes
Authors: Moss Asger Barkholt , Garg Sahil , Mirolo Marta , Giron Rodriguez Carlos , Ilvonen Roosa , Chorkendorff Ib , Drnec Jakub , Seger Brian
Published: July 2022

CO2 electrolysis is a promising technology for a renewable feedstock of carbon-based chemicals. Membrane Electrode Assembly (MEA)-based CO2 electrolysers have been demonstrated to run at commercially relevant current densities. However, the MEA approach can suffer from an unstable production of targeted products, mainly caused by an increase in hydrogen production often within a few hours of operation. We conducted operando measurements in a custom-made electrochemical cell (with an electrode area of 64 mm2) using a high-energy synchrotron X-ray source to study CO2 electrolysis over Cu-based gas diffusion electrodes (GDEs). A series of experiments have been performed between 100 to 250 mA cm−2, showing a change in product distribution as a function of time. Expectedly, this is caused by an increase in water content in the GDE (also called as flooding of GDE) rather than any change of the catalyst itself, e.g. slow depletion of subsurface oxygen. Interestingly, we found that while the increase in water content is causing a gradual degradation of the performance, salt precipitation also had a major influence on water management as well. By having an in-line GC attached to the cell, we could monitor both cathodic and anodic performance as a function of time and relate this to variations in water content throughout the device. Variations in cations played a substantial role in modifying the hydration properties of the device adding an additional effect cations have beyond their role in catalysis. The insights generated from this work will allow future researchers to engineer devices that can maintain proper water management and thus entail long term stability.
(Invited) Electrocatalytic Reduction of Nitrate: Insight from Manipulating Adsorbate Affinity
Authors: Stoerzinger Kelsey A
Published: July 2022

Fertilizer use and fossil-fuel combustion has increased nitrate concentrations in many wastewaters and watersheds to levels that threaten environmental and human health. Consequently, treatment of nitrate-contaminated water is a growing area of energy consumption. Electrocatalytic nitrate reduction offers a distributable treatment solution also capable of producing value-added products (e.g. ammonium), using electrons as a reducing agent at ambient temperatures and pressures. However, nitrate reduction occurs at similar electrochemical potentials to water reduction, reducing the Faradaic efficiency particularly in dilute nitrate concentrations characteristic of wastewater. Here we consider how changing a catalysts’ affinity for nitrate (via oxide supports) or its relative affinity for protons (via electronic structure) impact activity and selectivity of the electrocatalytic nitrate reduction reaction in neutral media.
A Spectroscopic Investigation of Photochemical Nitrogen Fixation
Authors: Hatzell Marta , Liu Yu-Hsuan
Published: July 2022

Photochemical nitrogen transformations were initially pioneered by a prominent Indian soil scientist, N.R. Dhar, in the 1930-40s[1]. Others continued to evaluate this process in the presence of liquid water, water vapor, and oxygen. These results remained unverified until 1977, when Schrauzer and Guth also began to investigate this process on natural minerals[2]. Since the 1970s photochemical nitrogen fixation has been widely studied on a number of photocatalyst[3]. Most conclude that nitrogen is reduce to ammonia through a direct electron-transfer based process. However, the reaction mechanism has not been clearly mapped using spectroscopic techniques. Here, we examine the reaction pathway for nitrogen fixation to ammonia on titania based photocatalyst using multiple spectroscopic techniques. We also aim to focus our talk on explaining the role hole scavengers play in enabling this reaction.

[1]Dhar, N. R., and N. N. Pant. "Nitrogen loss from soils and oxide surfaces." Nature 153.3873 (1944): 115-116.

[2] GN Schrauzer and TD Guth. Photocatalytic reactions. 1. Photolysis of water and photoreduction of nitrogen on titanium dioxide. Journal of the American Chemical Society, 99(22):7189–7193,1977.

[3]Medford, Andrew J., and Marta C. Hatzell. "Photon-driven nitrogen fixation: current progress, thermodynamic considerations, and future outlook." Acs Catalysis 7.4 (2017): 2624-2643.
Measurements of Ion Transfer Kinetics for the Study of Electrocatalyst Corrosion in Gas Diffusion Electrode Microenvironments
Authors: Thurman Kira A. , Zhao Yang , Boettcher Shannon W. , Kempler Paul A.
Published: July 2022

Nanoparticulate Au, Ag, and Cu films with percolating ion-conducting polymers are common within devices for the electroreduction of carbon dioxide (CO2) to carbon monoxide, hydrocarbons, and alcohols. The kinetics of ion-transfer are influential on the rate of corrosion and catalyst sintering, but direct measurements of ion-transfer rates are challenging at bulk metal electrodes. We present data on the corrosion kinetics of metal nanoclusters and monolayers deposited via underpotential deposition on well-oriented and/or single-crystal metal surfaces within suspended ionomer electrolytes. Our results support the important role of nucleation and growth in corrosion processes as well as the influence of structural anions on reactive intermediates present during corrosion reactions.

Figure 1
Atomically Dispersed Hollow Spherical Bimetallic(Co, Fe) Electrocatalysts Using Spray Pyrolysis with Improved Stability for Oxygen Reduction Reaction in Acidic Condition
Authors: Yim Kyungmin , Oh Sion , Kim Jinsoo
Published: July 2022

Pt and Pt-based alloys have been proven to be the most efficient catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, their susceptibility to CO deactivation and high cost as well as the limited reserves of Pt hinder their practical application. M-N-C catalysts for ORR from low-cost and earth abundant metal elements have exhibited a great promise to replace current platinum-based catalysts for PEMFCs. But insufficient stability is the major hurdle to prohibit their practical applications. In this study, we designed and synthesized bimetallic electrocatalysts which have enhanced stability in acidic condition with improved ORR activity by making metal interactions. Bimetallic (Co, Fe) oxides were prepared first by spray pyrolysis. Spray pyrolysis has advantages of component dispersibility and making hollow sphere that is ideal structure for mass transport without template. The product electrocatalysts showed high surface area and catalytic activity with reduced mass transport resistance. The synthesized bimetallic catalysts were analyzed by BET, XAFS, HR-STEM and electrochemical analysis system.
Exploring the Synergistic Relationship between Organic Synthesis and Electrochemistry
Authors: Moeller Kevin D , Feng Enqi , Ji Chang , Jing Qiwei , Medcalf Zachary
Published: July 2022

From a personal perspective, it is a joy to watch the larger organic synthesis community embrace and impressively develop new electrochemical methods. Those efforts are teaching us a great deal about not only electrochemical methods, but also how to best take advantage of the opportunities those methods offer. In our group, we continue to contribute to this larger enterprise by examining the role of direct electrochemical oxidation in the exploration of new oxidative cyclization strategies and the radical cation intermediates that are central to their success. These efforts have recently led to new umpolung reactions involving imine groups that are both setting the stage for introducing new levels of selectivity into the formation of non-natural amino acid building blocks and triggering new cascade types of reactions.

Interestingly, the relationship between organic synthesis and electrochemistry can also be viewed in the opposite direction with the new synthetic chemistry being developed in order to facilitate exciting opportunities to expand the scope of electrochemical experiments. For example, new synthetic methods that allow for the site-selective generation of chemical reagents have enabled the construction of complex molecular surfaces on addressable microelectrode arrays. The efforts set the stage for using the microelectrode arrays as analytical devices for rapidly screening the binding behavior of small molecule libraries with biological targets. The method offers a previously unknown level of quality control over the molecular library, and it enables the binding events to be monitored in "real-time" as they happen. However, more complex reactions leading to more complex addressable surfaces also requires better methods for characterizing what has been made and analyzing the biological interactions that arise.

Not surprisingly, the exploration of these new electrochemical tools is beginning to “give back” to the synthetic arena, and a number of preparative scale synthetic applications have now arisen based on the concept of site-selective reagent generation. For example, we have recently discovered that the strategy developed for confinement of a chemical reagent to a specific site on a microelectrode array can also be used to introduce new selectivity into solution phase chemical reactions. In the talk to be given, the interplay between organic synthesis and electrochemistry will be highlighted with an emphasis on how that interplay enables the development of new solutions to challenging synthetic problems.

References:

For reviews see Moeller, K. D. Chem. Rev.
2018, 118, 4817-4833, Jing, Q; Moeller, K. D. Accounts of Chem. Res.
2020,
53, 135-143, and Krueger, R.; Moeller, K. D. J. Org. Chem.
2021, 86, 15487-15865.
Electrochemical Reactivity of N-Alkoxyphthalimides, Towards O Radicals Electrogeneration and Use in Electrosynthesis
Authors: Chicas-Banos Diego Francisco , Gonzalez Bravo Felipe , Miranda Luis Demetrio , Sartillo-Piscil Fernando , Frontana-Uribe Bernardo Antonio
Published: July 2022

N-alkoxyphthalimides (NAPIs) are compounds known for the capability of oxygen-centered radical generation in the presence of tin reagents and radical initiators,[1] which have led to some inovative synthesis strategies.[2,3] Their reported electrochemical behavior is quite different: carbonylic compounds are obtained through cathodic reduction benzylic NAPIs.[4] Encouraged by an exciting "oxidation under cathodic conditions," we focus our studies on contrasting experimental with simulated cyclic voltammetry data using specialized software aiming to prove a plausible mechanism. The synthetic application to accessing carbonylic compounds through NAPIs electrochemical reduction has been assessed, evaluating different solvents, supporting electrolytes and current densities, and the tolerance of other reactive moieties to the reaction conditions.

[1] Kim, S.; Lee, T. A.; Song, Y. Facile Generation of Alkoxy Radicals from N-Alkoxyphthalimides. Synlett
1998, No. 5, 471–472.

[2] Cortezano-Arellano, O.; Quintero, L.; Sartillo-Piscil, F. Total Synthesis of Cephalosporolide E via a Tandem Radical/Polar Crossover Reaction. The Use of the Radical Cations under Nonoxidative Conditions in Total Synthesis. J. Org. Chem.
2015, 80 (5), 2601–2608.

[3] Zhu, H.; Leung, J. C. T.; Sammis, G. M. Strategies to Control Alkoxy Radical-Initiated Relay Cyclizations for the Synthesis of Oxygenated Tetrahydrofuran Motifs. J. Org. Chem.
2015, 80 (2), 965–979.

[4] Syroeshkin, M. A.; Krylov, I. B.; Hughes, A. M.; Alabugin, I. V.; Nasybullina, D. V.; Sharipov, M. Y.; Gultyai, V. P.; Terent’ev, A. O. Electrochemical Behavior of N-Oxyphthalimides: Cascades Initiating Self-Sustaining Catalytic Reductive N―O Bond Cleavage. J. Phys. Org. Chem.
2017, 30 (9), 1–15.

Figure 1
Electrochemistry of Hypervalent Bromine(III) Compounds
Authors: Francke Robert , Mohebbati Nayereh , Sokolovs Igors , Suna Edgars
Published: July 2022

The chemistry of hypervalent halogen species has experienced remarkable advancement in the recent decades [1]. However, in comparison to the well-explored hypervalent iodine(III) compounds, little research has been done on the isoelectronic bromine(III) counterparts [2]. This is mainly due to the difficult-to-control reactivity of λ
3-bromanes as well as to the challenges associated with the conventional protocol for their preparation from the highly toxic and corrosive precursor BrF3 [3]. In this context, we present a straightforward and scalable approach to λ
3-bromanes by anodic oxidation of parent aryl bromides. A series of para-substituted λ
3-bromanes with remarkably high redox potentials spanning a range from 1.86 V to 2.60 V vs. Ag/AgNO3 was synthesized by the electrochemical method. We demonstrate that the bench-stable bromine(III) species can be activated by addition of a Lewis or a Brønsted acid and used for various synthetic applications [4].

The developed electrochemical approach to λ
3-bromanes offers considerable advantages compared to previously established methods since stoichiometric reagents are replaced by electric current and the use of hazardous precursors is omitted. Therefore, our approach may open the door to the development of unprecedented synthetic transformations that would benefit from the unique properties of hypervalent bromine(III) species. Mechanistic studies on formation and activation of the bromanes are underway [5].

References:

1. Yoshimura, A.; Zhdankin, V. V., Chem Rev
2016,
116, 3328-435.

2. Miyamoto, K., Chemistry of Hypervalent Bromine. In PATAI'S Chemistry of Functional Groups
2018, pp 1-25.

3. Farooq, U.; Shah, A. A.; Wirth, T., Angew. Chem. Int. Ed.
2009, 48, 1018-1020.

4. Sokolovs, I.; Mohebbati, N.; Francke, R.; Suna, E., Angew. Chem. Int. Ed.
2021,
60, 15832-15837.

5. Mohebbati, N.; Sokolovs, I.; Woitke, P.; Leito, I.; Roemelt, M.; Suna, E.; Francke, R.; 2022, manuscript in preparation.

Figure 1
Interpretations of Electrochemical Impedance Drift at Different Surfaces
Authors: Halpern Jeffrey M , Ziino Emily , Panahi Zahra , Marnoto Sabrina , Austin Katherine , Feeney Stanley
Published: July 2022

Electrochemical impedance spectroscopy (EIS) is used to evaluate the resistive state of an electrode surface. EIS is growing more popular in evaluating materials for biosensors and energy applications. In the case of biosensors, EIS can passively evaluate the binding event of a biomolecule to a surface recognition element. We have studied EIS inconsistent measurements from a bare carbon electrode under various conditions to evaluate the associated drift over multiple runs.[1] Without changing any variables run-to-run, a measurable drift can be expressed linearly or as a Langmuir isotherm over multiple measurements. The total change in charge transfer resistance is dependent on the solution and media, including the choice of surfactant used to solubilize various analytes.

Herein we will report our progress of EIS measurements from multiple different surfaces including peptides, polymers, and bare electrodes. We found that drift can be associated with specific surface changes (decoupling of surface modification or changes in surface states) and adsorbing of solution media to the surface. In the case of the bare electrode, surfactant and solution choice is important to minimize drift and increase confidence in run-to-run measurements.

Acknowledgements: The authors would like to acknowledge the financial support from NIH (P20 GM113131).

References:

[1] E. Ziino, S. Marnoto, J.M. Halpern, Investigation to Minimize Electrochemical Impedance Spectroscopy Drift, ECS Trans. 97 (2020) 737–745. https://doi.org/10.1149/09707.0737ecst.
(Digital Presentation) TiO2 Photoelectrochemical Radical-Cation Vinylcyclopropane Rearrangements
Authors: Okada Yohei , Maeta Naoya , Kamiya Hihidero
Published: July 2022

In the field of synthetic organic chemistry, photochemical and electrochemical methods are often considered to be competing techniques that induce single electron transfer (SET). Recently, metal complexes and organic dyes have been extensively used as molecular sensitizers that can induce homogeneous bidirectional SET. On the other hand, heterogeneous monodirectional SET can be induced by electrodes, which differs from the photochemical methods. In this context, semiconductors are unique alternatives, since they can induce heterogeneous but bidirectional SET, potentially enjoying advantages of both photochemical and electrochemical methods. Such semiconductor "photoelectrochemical" methods may trigger the reactions that are otherwise difficult to achieve.

We have been developing electrochemical SET-triggered cycloadditions in lithium perchlorate (LiClO4)/nitromethane (CH3NO2) solution, which facilitates the generation of radical cations from electron-rich alkenes and styrenes. Recently, we also have been focusing on TiO2 photoelectrochemical SET-triggered cycloadditions, expanding a scope of the electrochemical versions. During the course of our study to develop new TiO2 photoelectrochemical SET-triggered cycloadditions, we unexpectedly found that vinylcyclopropane rearrangements was also possible in LiClO4/CH3NO2 solution. The reactions are initiated by oxidative SET by hole, which is followed by immediate ringopening of the cyclopropanes to generate distonic radical cations. It is expected that reductive SET by excited electron is also involved to realize effective net redox-neutral transformations. Experimental details, including preliminary mechanistic studies, will be presented in this talk.

References:

1. Chem. Rec.
2021, 21, 2223–2238.

2. Chem. Rev.
2018, 118, 4592–4630.

3. J. Org. Chem.
2020, 85, 6551–6566.
Electro-Conversion of Lignin to Highly Value-Added Products
Authors: Waldvogel Siegfried R
Published: July 2022

After cellulose and hemicellulose, lignin represent the most abundant part of the plant biomass. Due to the large waste stream originating from pulping processes, only Kraft lignin and lignosulfonates are of technical interest. Using electric current as sustainable reagent for degradation avoids transition metal catalysts and makes this approach very attractive. However, the natural complexity and stability of lignin make the depolymerization to useful organic building blocks a highly challenging task. The state of the art in the selective anodic degradation of Kraft lignin and other lignins will be reported. This contribution exclusively deals with the direct electrolysis and ex-cell approaches. The major focus will be given on the generation and cost efficient isolation of vanillin and related building blocks.

References:

[1] M. Zirbes, S. R. Waldvogel, Curr. Opin. Green Sustainable Chem.
2018, 14, 19–25.

[2] M. Zirbes, D. Schmitt, N. Beiser, D. Pitton, T. Hoffmann, S. R. Waldvogel, ChemElectroChem
2018, 6, 155–161.

[3] M. Zirbes, L. L. Quadri, M. Breiner, A. Stenglein, A. Bomm, W. Schade, S. R. Waldvogel, ACS Sustainable Chem. Eng.
2020
, 8, 7300–7307.

[4] M. Breiner, M. Zirbes, S. R. Waldvogel, Green Chem.
2021, 23, 6449–6455.

Figure 1
Probing Carboxylate Anolytes for Photo-Biofuel Cells through Combination of Bioinformatics and Electrochemistry
Authors: Beaver Kevin , Minteer Shelley D.
Published: July 2022

Photoheterotrophic purple bacterium Rhodobacter capsulatus has recently gained attention for its high halotolerance and its photo-enhanced extracellular electron transfer via exogenous quinone redox mediators, opening opportunity for self-powered decontamination of saline wastewater. Biodegradation of malate and succinate in R. capsulatus electrochemical systems has undergone prior examination, although a consistent bioelectrochemical system to comparatively study multiple carbon sources has not previously been developed. In this study, electrochemical techniques, biological assays, and computational tools were combined to evaluate malate, succinate, propionate, and lactate as oxidizable fuels in photo-enhanced microbial electrochemical systems. Specifically, cyclic voltammetry and amperometry data demonstrated that R. capsulatus generates distinctive photo-enhanced current densities dependent on both fuel identity and concentration. Bacterial growth curve studies were in agreement with the electrochemical data, indicating that lactate, which yielded the greatest bio-anodic current density (9.5 ± 1.9 µA cm-2), allowed the bacteria to grow more rapidly than the other substrates, suggesting its effectiveness as a fuel. Moreover, propionate appeared to be the fuel least efficiently utilized by R. capsulatus, having the slowest growth curve and the lowest current density generation (1.3 ± 0.2 µA cm-2). Finally, high-throughput differential gene expression analysis allowed for illuminating the physiological underpinnings of the observed differences between substrates. Most remarkably, cells grown in lactate were found to overexpress light harvesting complex II proteins and to underexpress flagellar motility proteins, which both correspond to the high photo-enhanced current density in lactate bioanodes compared to malate and propionate.
Living Photovoltaics Based on Recombinant Expression of Mtra Decaheme in Photosynthetic Bacteria
Authors: Reggente Melania , Schuergers Nils , Politi Sara , Mouhib Mohammed , Antonucci Alessandra , Boghossian Ardemis Anoush
Published: July 2022

At the center of microbial bioelectricity applications lies the critical need to express foreign heme proteins that are capable of redirecting the electron flux of the cell’s metabolism. This study presents a genetic construct for the heterologous expression of the periplasmatic decaheme MtrA c-type cytochrome from S. oneidensis MR-1, a dissimilatory metal-reducing exoelectrogen, inside the light-harvesting bacterium, Synechocystis sp. PCC 6803. Protein expression was verified through western-blotting and immunostaining, and oxygen evolution, optical density, and absorption measurements confirm sustained cell activity and viability under the tested expression conditions. Furthermore, the bioengineered cells show enhanced mediated exoelectrogenicity, as confirmed through a colorimetric iron assay and electrochemical measurements. Compared to wildtype cells on graphite electrodes, the bioengineered cells show a 2-fold increased extracellular electron transfer. The increased capacitance obtained under illumination and suppressed photocurrents in the presence of the photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) suggest increased extraction of photosynthetically derived electrons from the recombinant cells. The improved bioelectricity transport across the outer membranes, as achieved through the heterologous heme expression inside cyanobacteria, presents new opportunities for re-wiring the metabolisms of light-harvesting microbes.
Cytochrome C Oxidase Deficiency Detection Using SECM in Living Cells
Authors: Thind Shubhneet , Kuss Sabine , Singh Vikram
Published: July 2022

Cytochrome c Oxidase Deficiency (COXD) is an inherited disorder characterized by the absence, abnormality, or mutation in the genes encoding for the Cytochrome c Oxidase protein (COX)1. COXD results in severe muscle weakness, heart, liver and kidney problems and brain damage in infants, leading to death at birth or shortly thereafter2. With no cure for this disorder, finding an efficient, inexpensive, and early way of diagnosis is essential, as muscle biopsy, the current method of detection, is expensive, invasive, and time-consuming. Using electrochemistry, Cytochrome c Oxidase activity has successfully been quantified in bacteria, specifically in Bacillus subtilis and Escherichia coli by employing the redox mediator N, N, N’,N’-tetramethyl-para-phenylene-diamine (TMPD)3. This presentation demonstrates that by means of Scanning Electrochemical Microscopy (SECM), Cytochrome c Oxidase activity can also be quantified in living human epithelial and cancer cells. Thereby, COX oxidizes TMPD to TMPD+•, which is reduced at a microelectrode, regenerating TMPD. The resulting change in electrochemical current enables the quantification of COX activity. The presented research will form the basis for an analytical assay for the detection of COXD in infants, allowing for early intervention and saving lives of children.

References

1,2 NORD. (n.d.). Cytochrome c Oxidase Deficiency. National Organization for Rare Disorders (NORD). https://rarediseases.org/rare-diseases/cytochrome-c-oxidase-deficiency/

3 Kuss, S. et al. (2017). Electrochemical recognition and quantification of cytochrome c expression in Bacillus subtilis and aerobe/anaerobe Escherichia coli using N,N,N′,N′-tetramethyl-para-phenylene-diamine (TMPD). Chemical Science, (11). https://doi.org/10.1039/c7sc03498a
Electrochemical Detection of Tobramycin Resistance in Pseudomonas Aeruginosa
Authors: Lopes Luma Clarindo , Hayat Muhammad , Kuss Sabine
Published: July 2022

Pseudomonas
aeruginosa are Gram-negative anaerobic bacteria and is listedby the World Health Organization as one of the critical antibiotic-resistant pathogens1. The treatment for P. aeruginosa infection can be challenging, since this pathogen often exhibits an enhanced resistance to antibiotics, including aminoglycosides, such as Tobramycin (TOB). These are called mucoid strains and are mainly found in the lungs of cystic fibrosis patients, where it is a common cause of death for these individuals2. The overall goal of the presented work is the development of an electrochemical method capable of detecting TOB uptake in P. aeruginosa. Drug susceptible and drug resistant strains of P. aeruginosa were exposed to a TOB solution for different time intervals (Figure 1). By removing organisms from the solution after incubation, the remaining TOB in solution can be determined by electrochemistry. Resistant bacteria strains showed significantly lower TOB uptake than susceptible organisms, because cellular drug resistant mechanisms enable them to inhibit TOB absorption. The presented drug uptake studies demonstrate the sensitivity of electrochemistry to detect drug resistance in living bacteria.

References

Singh, M., Yau, Y. C. W., Wang, S., Waters, V. & Kumar, A. MexXY efflux pump overexpression and aminoglycoside resistance in cystic fibrosis isolates of pseudomonas aeruginosa from chronic infections. Canadian Journal of Microbiology
63, 929–938 (2017).

Germoni, L. A. P., Bremer, P. J. & Lamont, I. L. The effect of alginate lyase on the gentamicin resistance of Pseudomonas aeruginosa in mucoid biofilms. Journal of Applied Microbiology
121, 126–135 (2016).

Figure 1
Correlating Raman and X-Ray Absorption Spectroscopy to Analyze Defects in Hematite Photoandoes
Authors: Liu Yutong , Smith Rodney
Published: July 2022

Over two decades of research on hematite photoanodes have generated significant information on the electronic structure, photophysics and electron transfer mechanism for the oxygen evolution reaction. A surprisingly high degree of variability in photoelectrocatalytic performance continues across the literature despite these advances, however, suggesting missing information and uncontrolled variables. This encouraged us to pursue spectroscopic methods capable of identification, and possibly quantification of specific defects within the hematite lattice, and to map their presence to behaviors observed in photoelectrochemistry. We approach this issue by applying structure-property analysis to hematite samples treated under either O2 or N2 environments with variable performance in photoelectrocatalytic oxygen evolution. X-ray absorption fine-structure spectroscopy and Raman spectroscopy can provide short-range coordination shells and longer-range order feature respectively to describe the structure of samples across the series. Different correlations between these structural parameters and photoelectrochemical performance reveal distinct defects for sample sets annealed in O2 or N2. These distortions can be observed by processed Raman spectrum data, suggesting that it may be possible to calibrate the width, energy, and intensity of peaks in Raman spectra to enable direct analysis of defects in hematite photoanodes.
Photosynthetic Reaction Centres Assembled on a Gold Electrode and the Photocurrent - Potential Response
Authors: Jun Daniel , Grzedowski Adrian , Beatty J. Thomas , Bizzotto Dan
Published: July 2022

The photosynthetic reaction centre (RC) from Rhodobacter sphaeroides has been studied for use in biohybrid solar cells. Much of the previous work has focussed on improving photocurrent generation by loading the electrode surface with many copies of the protein resulting in multilayers. The primary disadvantage with this approach is the random orientation of proteins, with some supposedly oriented properly. We used RCs with Cys for covalent attachment to a gold electrode and for proper orientation. Areas of bare electrode surface and RCs bound non-specifically (i.e. not bound via the Cys) were competitively displaced by an insulating, non-redox layer of mercaptohexanol (MCH). The adsorbed monolayer of RCs was imaged using atomic force microscopy to detail the distribution of RCs on the gold surface for surfaces prepared with different RC deposition concentrations. Photocurrents were measured for all RC modified surfaces using a LED modulation method which enabled measurement of photocurrent in the presence of large faradaic currents from the sacrificial reactant (hydroquinone) at a variety of applied potentials.[1] The photocurrents generated from a monolayer composed of RCs and MCH resulted in consistent photocurrent currents. which enabled modeling of the photocurrent generation using the Marcus-Hush-Chidsey theory to extract a reorganization energy for this process. Multilayers of adsorbed RCs were distinctly different and revealed that the local environment in which the RCs are embedded significantly influenced photocurrent generation.

[1] Jun, D.; Beatty, J. T.; Bizzotto, D. Highly Sensitive Method to Isolate Photocurrent Signals From Large Background Redox Currents on Protein‐Modified Electrodes. ChemElectroChem
2019, 6 (11), 2870–2875.
Transport Phenomena in Ion-Exchange Membranes
Authors: Solberg Simon Birger Byremo , Burheim Odne Stokke
Published: July 2022

Ion-exchange membranes (IEM) are an essential component of electrochemical systems such as reverse electrodialysis (RED) and flow batteries. For RED, the membranes separate alternating concentrate and dilute solutions, creating emf. Stacks of such repeating units in series can be used as flow batteries [1] or to produce hydrogen [2] given appropriate electrode selection. Using non-equilibrium thermodynamics, the coupled solute and solvent transport through IEM may be understood in terms of transport numbers [1]. This work highlights the coupling between salt and water fluxes through membranes in RED, and the implications for the efficiency of various technologies which rely upon IEM in contact with aqueous solutions. In general for a mixture of one solute and solvent, the water transported together with ions across the IEM decreases the permselectivity, and thus the emf, of the membrane.

[1] D. Bedeaux, S. Kjelstrup, Non-Equilibrium Thermodynamics of Heterogeneous Systems, World Scientific, 2008.

[2] K. W. Krakhella, M. Morales, R. Bock, F. Seland, O. S. Burheim, K. E. Einarsrud, Electrodialytic Energy Storage: Permselectivity Stack Measurements and Life-Cycle Analysis, Energies 13, 2020.
Cyano-Anion Intercalated Layered Double Hydroxides for Electrocatalytic Degradation of Acetaldehyde in Gas Phase
Authors: Muthuraman Govindan , Choi Youngyu , Daekeun Kim
Published: July 2022

Layered double hydroxides (LDHs) are identified as potential material in water splitting or oxygen evolution reaction (OER). Since the water splitting potential is minimized when the use of LDH modified electrode, the application of the LDHs has been still challenged in air pollution control but the water splitting potential should be attempted to extended. Anions or cations intercalation has many applications in electrocatalysis and energy harvesting field. In this approach, the present work aimed to investigate a cyano-anion intercalation on NiCo-LDH and its application to degradation of acetaldehyde in gas phase.

The NiCo-LDH was prepared using coprecipitation method under a low temperature. The prepared NiCo-LDH was intercalated with cyano-anion using KCN. After surface characterization to confirm the intercalation of cyano-anion, the NiCo-CN-LDH was coated on a 3D metal foam electrode using a 5% Nafion solution. Redox behavior of the prepared NiCo-CN-LDH electrode was observed in 1M KOH solution by cyclic voltammetry (CV) technique. Once identified the water splitting potential window, the NiCo-CN-LDH electrode was examined on the acetaldehyde (AA) reduction/oxidation in the 1M KOH solution. To evaluate the NiCo-CN-LDH electrode effect on AA, the potential truncated CV at various potential regions. After solution-phase CV analysis, the NiCo-CN-LDH electrode was fitted into Nafion membrane divided electrolytic flow through cell for the gas-phase degradation analysis either by anodic or cathodic half-cell. The NiCo-CN-LDH electrode’s redox behavior was analyzed and compared with solution phase redox behavior. Then the NiCo-CN-LDH electrode was applied on the AA degradation either by oxidation or reduction by continuous flow of AA gas. The degradation efficiency was monitored by ex-situ GC-MS. The promoted effect of cyano-anion on widening the water splitting potential window and its usage on gas phase AA degradation will be discussed in detail at the conference.

Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant No.: NRF-2021R1I1A1A01049901) and from the Grant No. NRF-2020R1A6A1A03042742.
Characterizing Recast Nafion® Film Electrode Interface Diffusion and Kinetics in a Non-Aqueous System
Authors: Lehto Danielle , Claire Anna , Zacher Peter , Knoche Gupta Krysti
Published: July 2022

The effect of recast Nafion® films on platinum working electrodes in acetonitrile will be characterized by cyclic voltammetry and rotating disk voltammetry. Until now, the behavior of recast Nafion® in a non-aqueous system has not been reported in this way. The behavior of recast Nafion® films in acetonitrile has been anecdotally observed to be different from the behavior in aqueous solutions, which have also been comprehensively studied1,2. The reversible redox couple of Tris(2,2′-bipyridine)ruthenium(II) hexafluorophosphate, Ru(bpy)3
2
++, in an acetonitrile electrolyte solution will be compared between a bare platinum working electrode and a recast Nafion® film coated platinum working electrode by cyclic voltammetry. In cyclic voltammetry the convective mass transport of the species is limited only to the diffusion at the stationary electrode interface. In rotating the working electrode (RDE) the limitation on mass transport is extended beyond the stationary diffusion behavior. The current is dependent on and limited by the mass transport of the species to the electrode interface where it can undergo redox, the limiting current of both a bare platinum working electrode system and of a recast Nafion® film coated platinum working electrode will be observed by changing the rotation rate of the RDE. The diffusion interface of the electrode inside an acetonitrile solution of Ru(bpy)3
2
+ and an electrolyte will be determined by rotating disk voltammetry at a bare platinum working electrode and at a recast Nafion® film coated platinum working electrode. The film solution interface thickness will be reported along with the effect on the diffusion of the interface between bare and recast Nafion® coated platinum working electrodes.

1. S. K. Zecevic et al 1997 J. Electrochem. Soc.
144 2973

2. T. A. Zowodzinski, S. Gottesfeld et al 1997 Advances in Electrochemical Sciences and Engineering
Sustained Release of AgNO3 Additive in Carbonate Electrolytes for Stable Lithium Metal Anodes
Authors: Kang Hyeonmuk , Kim Taehee , Hwang GyuSeong , Shin GeunHyeong , Lee Junho , Cho EunAe
Published: July 2022

With increasing energy storage demand, research on high energy density and stable battery became essential. Among different anode materials for lithium batteries, lithium metal is an ideal anode material as it has low redox potential and high specific capacity. Therefore, for post-lithium ion battery with high energy density cannot avoid using lithium metal as an anode. However, lithium metal anode has stability and safety issues due to dendritic growth. Lithium metal in contact with organic electrolyte reacts with the electrolyte to form solid electrolyte interface (SEI). SEI prevents further electrolyte consumption, however presence of unstable SEI causes uneven lithium ion diffusion through the SEI layer and induces lithium dendrite growth. Therefore, uniform deposition of lithium and stable SEI is important to operate lithium metal anode safely.

The application of nitrate additives in carbonate electrolyte has been very limited due to poor solubility. However, nitrate containing polymer interlayer can release additive constantly enabling nitrate act as an electrolyte additive. Herein, AgNO3 synthesized with PAN nanofibers (AgPAN) is used as an additive to induce uniform lithium deposition and stable SEI formation. In the symmetric cell test, life time of 20 µm thick lithium foil enhanced from 140 hr to 300 hr with AgPAN. Lithium nucleation overpotential disappeared and overall overpotential is reduced. Originally, plane lithium foil had the sparsely deposited dendrite shaped lithium, but with AgPAN lithium was evenly deposited and grow in spherical shape. Ag+ reduces on lithium metal surface acting as a lithium nucleation seed helping uniform lithium deposition and NO3
- reacts with lithium to form stable inorganic SEI layer (Li2O, Li3N, LiNxOy, and etc) resulting in stable cycling of lithium metal anode.
Graphene-Wrapped Silicon Nanoparticles for All-Solid-State Lithium-Ion Batteries
Authors: Gad Mariam , Almadhoun Mahmoud , Pope Michael
Published: July 2022

Current lithium-ion batteries consist of a graphite anode and a metal oxide cathode. Due to their relatively high energy density and rechargeability, they have enabled various applications over the past few decades. However, significant improvements to battery cost, performance, and safety for applications such as vehicle electrification require a shift to next-generation materials, such as silicon as an anode which offers higher capacity, as well as solid-state electrolytes (SSEs) which are non-flammable. Both of these technologies currently suffer challenges which have prevented their widespread adoption. Silicon suffers low conductivity, and large volume change on each cycle, subsequently causing loss in electrical contact and the formation of an unstable solid electrolyte interface (SEI) each cycle. This project aims to solve these challenges by wrapping silicon nanoparticles and a sacrificial spacing material with crumpled graphene sheets using a scalable, spray drying method, and coupling it with a solid electrolyte. The graphene shell provides electrical contact with the silicon and space for its expansion during lithiation. The solid electrolyte provides a safer alternative to liquid electrolytes, and further reduces the SEI formation which, with a liquid electrolyte, can leak into such crumpled structures. In this work we will present our initial results concerning the engineering of void space within the shell’s core while simultaneously improving its conductivity to maximize the achievable capacity and cycle life. We will explore different spacing material candidates such as chitosan which, upon heat treatment of the sample, would not only provide space for the expansion of silicon, but the residual nitrogen-doped carbon would also act as a conductive filler inside the crumpled structure. We will also present our initial work involving the solid electrolyte synthesis including an investigation of the effect of solvents on the structure of the electrolyte as well as powder mixing and solution infiltration methods to introduce high conductivity SSEs and their performance when coupled to the graphene-wrapped silicon anode structures.
Analysis of Deterioration Mechanism of Al-Pouch Film Used As Packaging Materials for Lithium Ion Batteries
Authors: Park Bo Keun , Kim Yong Min , Kim Ki Jae
Published: July 2022

Generally, lithium ion batteries (LIBs) can be divided into three different types: cylindrical, prismatic, and pouch-type LiBs with regard to the packaging form. Contrary to cylindrical or prismatic type batteries, pouch-type battery uses a pouch as an exterior material to protect inside of the cell from external influences, and have a metal lead-taps to receive and deliver electricity from external source. To safeguard the inside of the lithium ion battery, the pouch must have high resistance to gas and moisture permeability and excellent corrosion resistance to electrolytes.

However, Al-pouch can be prone to contamination from electrolyte containing lithium salt during the electrolyte injection process, a key part of their manufacturing process. This electrolyte contamination can be fatal to the long-term reliability or durability of pouch-type LiBs. In this study, we investigate deterioration behavior of aluminium pouch film due to the electrolyte contamination. In order to clarify deterioration mechanism of Al-pouch film, we prepared exposure test of Al-pouch film and dummy cell samples which were stained by electrolyte droplet (LiPF6 in EC:EMC=1:2 (v/v) + 2 % VC). The change of micro-structure of the samples was tracked during 20 weeks by storing them under accelerated test conditions (RH 95 %, 60 ℃). As a result, we find out severe defect of the samples of Al-pouch film by damage to outermost nylon film and aluminium layer, and confirmed the effects on the battery after the defects occurred.

To understand such phenomena, the micro-defect of Al-pouch films was observed by characterization techniques (XRD, FT-IR, SEM, EDX). We demonstrate that outermost layer of nylon film is damaged when it reacts with an electrolyte containing LiPF6 salt such as decreasing crystallinity, surface crazing, forming microdefects. The degradation of nylon film leads to severe surface cracking, followed by nylon locally peeling off from the Al-pouch. Peeling of the nylon film causes to expose the underlying thin aluminum film that constitute the middle layer of Al-pouch. Once partially exposed to the atmosphere, severe pitting corrosion of the aluminum film occurs due to atmospheric moisture and acids produced by LiPF6. Finally, a large amount of moisture to easily penetrate pouch-type LiBs through these corroded pits, showing the detrimental effects of electrolyte contamination on pouch-type LiBs’ long-term durability and reliability.

Figure 1