bluuebunny/crossref_metadata_2025_split huggingface dataset:
Online Stability Investigations of Platinum Electrodes in Nonaqueous Media
Authors: Ranninger Johanna , Nikolaienko Pavlo , Mayrhofer Karl J. J. , Berkes Balázs B. 
Published: July 2021

In the process of developing novel electrocatalysts, the focus mainly lies on finding highly active and selective materials. The stability of electrodes is often underestimated, even though a poor stability is inextricably related to economic losses. Fundamental understanding of electrode dissolution processes in nonaqueous media is not only crucial for applications like nonaqueous battery systems, sensors, capacitors but also for organic electrosynthesis. The reasons for electrode degradation are among others anodic dissolution, cathodic dissolution or cathodic corrosion. Enhanced knowledge of dissolution mechanisms, especially understanding the influence of factors like composition or structure of electrodes, electrolytes and temperature, is important to optimize the operation conditions of reactors, and with that limit electrode degradation and increase the lifetime of devices and improve processes.
Coupling electrochemical measurements with an inductively coupled plasma mass spectrometer (ICP-MS), allows online stability studies and gives valuable insights into degradation mechanisms of different electrodes and catalyst materials, which are relevant in various applications. We have developed an electroanalytical flow cell (EFC) coupled to an ICP-MS, which is suitable for the use in aggressive nonaqueous electrolytes. Furthermore, the EFC is operated in an argon filled glovebox, which allows otherwise unattainably strict control of experimental conditions, like the water content of electrolytes [1,2].
In order to demonstrate the capabilities of this novel method, dissolution of platinum as an ideal model system will be depicted first: this metal has excellent electrocatalytic activity and somewhat falsely supposed inertness. It is widely used in various fields of applications and its behavior in aqueous media is fairly well known. New aspects of its stability in different nonaqueous electrolytes are unveiled together with dependences on the chemical properties of the solvents and the conducting salts. While the dissolution behavior of completely water-free protic and aprotic electrolytes is very similar, the dissolution behavior changes markedly upon temperature variation or in presence of trace amounts of water.
Different platinum dissolution profiles in several nonaqueous electrolytes will be discussed and dissolution mechanisms will be proposed, based on studies with changing water content. The dissolution of this electrode material has been followed during a running electrosynthesis. The correlation of possible reaction intermediates with the stability will be illustrated for a Kolbe electrolysis.
Literature:
[1] J. Ranninger, et al., Electrochem. Comm., 2020, 114 (106702),
[2] J. Ranninger, et al., J. Electrochem. Soc., 2020, 167 (121507)
(Keynote) Nanostructured Materials for CO2 and Oxygen Reduction
Authors: Gewirth Andrew A. , Chen Xinyi , Esposito Anne Marie 
Published: July 2021

This talk addresses the reactivity associated with CO2 and O2 reduction. For CO2, electrodeposition of metals from plating baths containing 3 an inhibitor yields highly porous materials exhibiting enhanced activity for electrochemical reactions. Electrodeposition of CuAg or CuSn alloy films from such plating baths yields high surface area catalysts for the active and selective electroreduction of CO2 to multi-carbon hydrocarbons and oxygenates. Alloy films containing Sn exhibit greater efficiency for CO production relative to either Cu along or CuAg at low overpotentials. In-situ Raman and electroanalysis studies suggest the origin of the high selectivity towards C2 products to be a combined effect of the enhanced stabilization of the Cu2O overlayer and the optimal availability of the CO intermediate due to the Ag or Sn incorporated in the alloy. Sn-containing films exhibit less Cu2O relative to either the Ag-containing or neat Cu films, likely due to the increased oxophilicity of the admixed Sn. Additionally, modification of the Cu electrode with certain polymers yields substantially enhanced reactivity, due in part to control of the Cu2O layer.
For O2 reduction, we report the results of detailed magnetometry studies on non-precious metal oxygen reduction catalysts. The magnetometry clarifies uncertainties about the state of the metal in active catalysts and reports on how the catalysts change following alteration in preparation procedures, such as exposure to NH3.
(Invited) Highly Active OER Electrodes Derived from Fe-Doped Ni Oxyfluoride Formed by Anodizing of NiFe Electrodeposits
Authors: Habazaki Hiroki , Yamada Naohito , Yato Yuya , Kowalski Damian , Kitano Sho , Aoki Yoshitaka 
Published: July 2021

Because of the limited availability of fossil fuels and pertinent global environmental issues, hydrogen production via electrochemical water splitting using renewable resources is an important alternative for future energy economies. For efficient alkaline water electrolysis to produce hydrogen, we need to develop highly active and durable electrocatalysts, particularly for oxygen evolution reaction (OER) because of high overpotential. Anodizing of metals and alloys is a promising means of directly fabricating an OER electrocatalyst on a metallic current collector. Binder-free electrocatalysts are readily formed by anodizing. Since Fe-doped Ni oxyhydroxides and hydroxides are recently reported as highly active OER electrocatalysts in alkaline media. Here, we report anodizing of NiFe electrodeposits in fluoride-containing ethylene glycol electrolyte and the conversion of resultant nanoporous Fe-doped Ni oxyfluoride to highly OER active hydroxide during OER (1).
NiFe alloy films containing 7.2 – 21.1 at% Fe were obtained by electrodeposition on Ni substrate. Then, the alloys were anodized at 10 V in ethylene glycol electrolyte containing ammonium fluoride and water. The anodizing developed a porous layer consisting of crystalline NiF2 phase. XPS analysis revealed the presence of Fe and O as well as Ni and Fe. Thus, porous Fe-doped Ni oxyfluoride was developed by anodizing. The as-anodized NiFe alloys were initially less active for OER in 1.0 mol dm-3 KOH, but during potential cycling to OER potential, the OER activity was gradually enhanced. The enhancement was dependent upon Fe content, and the highest activity was obtained for the Ni-11.8 at% Fe. After activation, the porous layer was converted to amorphous hydroxide, and the fluoride content was highly reduced. Thus, anodically formed Fe-doped oxyfluoride on the NiFe electrodeposits is a suitable precursor of highly active OER electrocatalyst. The galvanostatic durability test exhibited the stable overpotential, disclosing the high durability of this electrocatalyst.
Reference

N. Yamada, S. Kitano, Y. Yato, D. Kowalski, Y. Aoki and H. Habazaki, ACS Applied Energy Materials, in press, doi.org/10.1021/acsaem.0c02362.
(Invited) Highly Active Pt-Modified Catalyst for the Selective Electro-Oxidation of Saccharides
Authors: Coutanceau Christophe , Neha Neha , Baranton Stève 
Published: July 2021

The increasing demand of energy and high value-added compounds, and the extinction of fossil resource reservoirs result in replacing fossil resources with biomass. Cellulose and hemicellulose represent 40 to 60 wt% of agriculture green wastes and can be considered as raw materials. After transformation of these biopolymers into saccharides, the latter can serve as platform molecules to produce chemicals with high value added and/or industrial interest. In that context carbohydrates need to be studied more deeply for obtaining every possible outcome. Focusing on environmental problems, electro-reforming can provide hydrogen together with a supplementary valuable industrial compound, but this last process must show very high selectivity and low cost to compete with classical biotechnological methods for sugar conversion.
monosaccharides, disaccharides and oligosaccharides are complex molecules bearing several oxygenated functions (primary alcohol, secondary alcohol, anomeric group) that are potentially electrochemically reactive. Therefore, it is needed to develop catalysts displaying very high activity at low potentials and very high selectivity towards a given compound. For this purpose, the synthesis and characterization of Pt-based binary catalysts will be presented and their electrocatalytic behavior towards the oxidation of saccharides (glucose and cellobiose bearing a reductive anomeric function, and methylglucoside and trehalose with a protected anomeric function) will be first studied by linear scan voltammetry in a classical three-electrode cell to evaluate their activity and by in situ infrared spectroscopy to determine reaction intermediates and products as a function of the electrode potential. Best candidates will be used as anode catalysts to perform the electroreforming of saccharides in a two-electrode electrolysis cell with simultaneous production of hydrogen at the cathode. Reaction products will be analyzed by HPLC, MS, and 1H and 13C NMR to determine the selectivity and the efficiency of the system.
From the electrochemical and analytical results, the high efficiency of the Pt9Bi1/C catalysts will be emphasized, the electro-reactivity of the different functions determined, and reaction mechanisms discussed.
New Screen-Printed Carbon Sensor for Trace Analysis of Thallium(I)
Authors: Kozak Jędrzej , Tyszczuk-Rotko Katarzyna 
Published: July 2021

Thallium is an element classified as a heavy metal. In chemical compounds it occurs on +1 and +3 oxidation levels. In the context of the toxicity of this element, Tl(I) is most often referred to. The similarity of Tl+ ions to K+ ions is the basis of the mechanism of toxic action of Tl(I) on the human body. The main features of thallium poisoning in humans are gastroenteritis, polyneuropathy and alopecia Thallium in the environment comes from both natural and anthropogenic sources. Due to the high toxicity of thallium and its easy absorption by the human and animal organisms, it is extremely important to monitor the amount of this element, including in water.
The purpose of this work is to present a new method for determination of thallium in water samples using a screen-printed sensor with carbon working electrode modified with multiwalled carbon nanotubes and in-situ plated bismuth film. The measurements were carried out using square wave anodic stripping voltammetry (SWASV) method. Simultaneous deposition of bismuth and thallium took place at a potential of -0.9 V for 180 s. Under optimized conditions a linear calibration curve was obtained in the range of Tl(I) concentrations from 1·10-8 to 1·10-6 mol L-1. The procedure allows to achieve the limits of detection and quantification of Tl(I), 2.8 × 10-9 and 9.3 × 10-9 mol L-1 respectively. The method was applied for determination of Tl(I) in spiked water samples from Vistula river.
[1] Kozak, J., Tyszczuk-Rotko, K., Rotko, M. Physicochemical Problems of Mineral Processing
2019
, 55(6), 1422-1428.
Investigations on the Mechanism of Oxygen Reduction in Ca(ClO4)2/DMSO-Electrolytes
Authors: Hegemann Martina , Hegemann Martina 
Published: July 2021

Within the context of our mechanistic research on processes in the Ca/ air battery, we studied in detail oxygen reduction using RRDE and DEMS. From an earlier DEMS study we know that on the Au electrode first a two electron transfer takes place and after that a one electron transfer. On Pt and GC electrode only the one electron process is taking place. [1] In Addition XPS – measurements show that a thin film was formed on the Au electrode. It was described, that the top layer of the film contains decomposition products but after Ar+ etching Ca(O2)2, CaO2 and CaO was found on the surface. [2] Here, we performed further measurements in this electrolyte system to clarify the mechanism which is taking place at the Au electrode. With the RRDE the ring potential was varied, the oxygen content in the electrolyte was varied and potential jump experiments were performed. To elucidate how many electrons are flowing not only during ORR, but also during product reoxidation, the DEMS measurement was repeated in our 6-electrode-thin-layer-flow-through-cell (flow rate of 5 µL/s) [3] to confirm the supposed reaction model. At Au-electrodes in Ca2+ containing DMSO we established the following reaction pathway: at low overpotentials oxygen is reduced to soluble peroxide, which can be reoxidized with two electrons; then, at higher overpotentials, a transition to a 1 electron transfer occurs with the formation of a thin (adsorbed) Ca(O2)2 layer a on the electrode. In Addition we used mixtures of TBA+ / Ca2+ and Li+/Ca2+ cations in DMSO to investigate the influence of the Ca2+ cation on the reduction of oxygen.
Acknowledgement:
The authors gratefully acknowledge the Federal Ministry of Education and Research (BMBF) for funding this work. This work is part of the MeLuBatt-project in the framework of the “Frischer Wind für Metall-Luftsauerstoff-Batterien”-initiative (03XP0110D).
[1] P. Reinsberg, C. J. Bondue, H. Baltruschat, J. Phys. Chem. C
2016, 120, 22179-22185.
[2] P. P. Bawol, P. H. Reinsberg, A. Koellisch-Mirbach, C. J. Bondue, H. Baltruschat, ChemRxiv (Preprint)
2020.
[3] C. J. Bondue, P. Königshoven, H. Baltruschat, Electrochim. Acta
2016, 214, 241–252.
(General Student Poster Session Winner - 3rd Place) Designing and Implementing a Tailored Alternative Data Analysis Algorithm (TADAA) to Evaluate Quasireversible Heterogeneous Electron Transfer Measurements By Square Wave Voltammetry
Authors: Haas Christian D , Coduto Joshua Richard , Leddy Johna 
Published: July 2021

Square wave voltammetry (SWV) is used to investigate fast electron transfer kinetics across a wide range of redox active species. SWV is an inherently faster, frequency dependent method as compared to most potential sweep methods. Sweep methods commonly implement an applied potential as a staircase of small potential steps. The frequencies of SWV can be related to sweep methods as the product of SWV frequency and the potential increment at each staircase step.
Recent work in our group has shown that k0 measurements for tris-bipyridine transition metal complexes can be made using SWV as the wave morphology changes with k0. Heterogeneous electron transfer rates are not reliably measured at the slower voltage perturbations (scan rates) available with cyclic voltammetry (CV). The heterogeneous electron transfer rates k0 for M(bpy)3
z+ complexes, where M = Ru2+, Os2+, Cr3+, Co2+, Co3+, and Fe2+ are sufficiently rapid that k0 is not reliably measured by CV for most of these complexes. Analysis of the SWV data is possible but not as facile as analysis of CV data. To better evaluate k0 measurements, an alternative data analysis algorithm for quasireversible heterogeneous electron transfer is developed based on classical finite difference simulations. The algorithm can be envisioned as converting voltammograms between CV and SWV. Because CV and SWV both contain a potential parameter and a time parameter (mV/s in CV; frequency and step height in SWV), the algorithm uses a “universal scan rate” to convert between all of the other potential and time-dependent parameters. The purpose of the algorithm is to simplify quantitative SWV data analysis and present information in context of the more commonly used CV.
Wearable Chemical Sensor Badge
Authors: Chapman Kimberly , Cozy Alison , Jung Elijah , Locke Ed 
Published: July 2021

Objectives

Under this program, a wearable chemical detection badge capable of detecting and alarming (visual + audible/vibratory) in the presence of relevant concentrations of toxic industrial chemicals (TICs) in air has been developed and demonstrated for ammonia, chlorine, hydrogen sulfide, and nitrogen dioxide. The badge will alarm via one of the user-chosen alarm modes in the presence of ½ Immediately Dangerous to Life or Health (1/2 IDLH) concentrations of these TICs in under 5 minutes. The technology operates in harsh environmental conditions (10-90% RH, -10 – 50 oC) and in the presence of interferents (e.g. smoke, fuels, bleach and diesel exhaust). The active sampling badge consists of a reusable detection device that is used in conjunction with a disposable colorimetric sensor coupon. The sensor badge is unobtrusive and can be worn in the breathing zone of the user with hands-free operation for up to 8 hours on battery power.

Results

Small prototype devices (2” x 2” x 0.5”) were manufactured based on feedback from expert first responder personnel. Key points from this feedback include:

Must have a low false alarm rate; no nuisance level alarms (e.g. PEL)

Alarm must be very visible/noticeable

Must be small and unobtrusive

Data logging would be beneficial for analysis at a later time

Prototype devices and associated sensor coupons were tested in the presence of PEL, ½ IDLH, and multiple IDLH concentrations of the target TIC analytes (ammonia, chlorine, hydrogen sulfide, and nitrogen dioxide) under harsh environmental conditions:
-10 oC, ~ 90%RH
23 oC, 10% RH/50% RH/90% RH
50 oC, 10% RH/50% RH/90% RH
and in the presence of environmental interferents including smoke (burning wood), diesel exhaust, diesel fuel and bleach. Utilizing four interrogation bands of the visible spectrum and combinatorial colorimetric response alarm criteria, the prototype badges performed well with no false positive or false negative alarms due to environmental interferent exposure, nuisance level (PEL) exposure, or harsh environmental conditions.

Conclusion/Significance

First Responders under duress need a simple, low-cost, rugged device capable of detecting the presence of harmful levels of Toxic Industrial Chemicals (TICs) with high fidelity while avoiding nuisance level alarms (e.g. OSHA PEL) and false alarms due to environmental contaminants (e.g. smoke, fuels, diesel exhaust). This prototype sensor technology fills an unmet need for the first responder and is adaptable for the incorporation of new sensors in the future.

Figure 1
How to Do Business with DHS S&T
Authors: Ervin Angela 
Published: July 2021

Established by Congress in 2003 as the research and development (R&D) arm of the Department of Homeland Security (DHS), the Science and Technology Directorate (S&T) focuses on providing technology solutions and knowledge products to mitigate the adverse consequences resulting from the release of chemical, biological, and agricultural threats.
DHS S&T research areas include chemical and biological defense, borders and maritime security and port of entry screening, critical infrastructure and resilience, cybersecurity, explosives detection and aviation screening, first responders, unmanned aerial systems, and tests, evaluations, standards, and systems engineering. In addition, S&T partners with academic, national laboratory, and other research organizations to address specific homeland security topics and threats and funds DHS S&T Technology Centers with subject matter experts in sensors and platforms, modeling and simulation, data analytics, hazard awareness and characterization, biometrics and identity, social sciences, and interoperability and compatibility.
Innovation is the driving force behind S&T’s work. Because potential solutions may exist outside the homeland security arena, S&T casts a wide, inclusive net to find and use the best technology available. During her presentation, Dr. Angela M. Ervin will outline the current work of DHS S&T and explain the process for requirements gathering for initiation of projects and programs. She will also discuss opportunities available for academia and industry to work with S&T as well as mechanisms to apply for funding.
Electrical and Label-Free Detection of T-Cell Activation Against COVID-19: A Method Towards Point-of-Care Monitoring of Immune System
Authors: Nami Mohsen , Han Patrick , Hanlon Douglas , Yosinski Shari , Edelson Richard , Reed Mark 
Published: July 2021

Despite great progress in biotechnology, COVID19 has revealed the inadequacy of current healthcare technologies to contain an infectious outbreak, specifically in rapid infection recognition to facilitate containment. Wide deployment of testing methods such as viral RNA (antigen) PCR and antibody detection have provided some relief in this regard; however, current technologies still require many hours to provide results. Thus, there remains a critical need for fast, sensitive, low-cost point-of-care (POC) biosensing assays to report on the infection status and immunity of patients. Emerging data on the importance of T-cell responses in generating long-term immunity against COVID19 has highlighted T-cell activation detection as a potential way for real-time monitoring native and acquired immunity. However, current approaches for T-cell stimulation monitoring are complex, laborious, time-consuming, and costly.
Here we provide proof-of-principle experiments which indicate that an electrical and label-free detection method based on CMOS-compatible silicon nanowire ion-selective field-effect transistors (SNW-ISFET) can act as a fast, sensitive, reliable, and low-cost approach to monitor T-cell response to pathogens such COVID-19. This technology enables direct detection of COVID-19-specific T-cells directly from patient blood, with potential utility as a POC diagnostic device. Detection of antigen-specific T-cell activation from clonal human T-cells lines utilizing CD8-restricted peptide-MHC complexes has been demonstrated using SNW-ISFET devices. The cell concentration was varied to achieve a clear understanding about the device sensitivity, detection limit, and reliability (Figure 1). SNW-ISFET structures were applied to detect T-cell activation in clonal T-cell lines and whole peripheral blood mononuclear cell (PBMC) with multiple cell concentrations (Figure 2). Reference experiments were applied to ensure the device reliability and sensing mechanism (Figure 3). These findings show that SNW-FETs platform are promising candidates for antigen-specific T-cell activation detection from whole blood.

Figure 1