bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Characterization of Catalyst-Ionomer Interactions for Pt Fuel Cell Electrodes Using Varied Carbon Supports
Authors: Foster Jayson , Zaccarine Sarah , Baez-Cotto Carlos , Dzara Michael , Kim Sara , Batool Mariah , Jankovic Jasna , Ulsh Michael , Mauger Scott A , Pylypenko Svitlana 
Published: November 2022

Proton exchange membrane fuel cells (PEMFCs) are a progressive technology capable of providing on-demand energy without contributing to greenhouse gases. To meet the needs of transitioning from lab-scale fabrication to large-scale manufacturing, further analysis of catalyst layers is necessary. A common issue within the cathode catalyst layer (CL) is non-uniform distribution of the ionomer within the catalyst layer. Additionally, the interface between catalyst and ionomer is not well understood.
X-ray photoelectron spectroscopy (XPS) is a highly surface-sensitive technique primed to provide new insights into the challenging interfacial interactions and chemistries among the catalyst, support, and ionomer. Although Nafion is inherently susceptible to X-ray degradation, XPS can be used effectively through a modified acquisition strategy developed previously in our group. In this work, XPS has been used to probe CLs with focus on the catalyst-ionomer interface and interactions using a series of electrodes prepared by a Mayer rod coating method. The catalyst-ionomer interface was investigated as a function of support material, Pt loading on the support, and ionomer loading. Surface information was acquired using ex situ and in situ XPS to emphasize the evolution of this technique’s capabilities at probing ionomer interactions. Complementary characterization with scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) in combination with energy-dispersive X-ray spectroscopy (EDS) mapping of catalysts and electrode cross-sections were utilized to visualize distribution of catalyst, carbon, and ionomer in the CL to assist with interpretation of XPS data. Results from this dataset emphasize the potential of this technique to study complex interfaces in PEM catalysts layers motivating further work expanding to other catalysts and ionomers.
Investigation of Surface Adsorption and Electrode Passivation during Electrochemical Oxidation of Redox-Active Organics
Authors: Shaheen Nora Adel , Carino Emily , Yang Zhenzhen , Trahey Lynn , Srinivasan Venkat , Akolkar Rohan 
Published: November 2022

Redox-active organic molecules (ROMs) have gained interest as electroactive materials for redox flow batteries (RFBs). Electrochemical properties of ROMs, i.e., their solubility and redox potential, can be tuned through molecular engineering of the base molecule. Previously, we reported values of the apparent anodic charge transfer coefficient α (values approaching 1) associated with the electrochemical oxidation of a model ROM, 4-hydroxy-TEMPO.1 Also, we have proposed an adsorption-mediated mechanism to explain this unusual value of α, and have presented evidence to support the occurrence of adsorbed intermediates. Here, we extend this investigation to gain further insights using techniques of slow-scan voltammetry and electrode cycling, and apply them to other ROMs. We will discuss results of spectroscopic and micro-gravimetric studies, which provide further insights into the physicochemical properties of the adsorbed surface-passivating films. Ramifications of these to implementation of ROMs in flow batteries will be discussed too.
[1] N. A. Shaheen, M. Ijjada, M. B. Vukmirovic, R. Akolkar. J. Electrochem. Soc.,
167 (2020) 143505.

Acknowledgements:

Investigation of the model ROM was supported by Breakthrough Electrolytes for Energy Storage (BEES)—an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award #DE-SC0019409. Work completed at Argonne was supported by the Joint Center for Energy Storage Research (JCESR), a U.S. Department of Energy, Energy Innovation Hub, and by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education (ORISE) for the DOE. ORISE is managed by ORAU under contract #DE‐SC0014664. All opinions expressed in this paper are the author’s and do not necessarily reflect the policies and views of DOE, ORAU, or ORISE.
(Invited) In-Situ/Operando X-Ray Absorption Spectroscopy: Methods and Challenges in Electrocatalysts Characterization
Authors: Zitolo Andrea 
Published: November 2022

During the last decades X-ray absorption spectroscopy (XAS) has proved to be a fundamental tool for understanding the nature of active catalytic species, especially in the form of highly dispersed, amorphous phases, and in the case of single atom catalysts. [1-4] The efforts in developing this technique under working conditions are justified by the extraordinary information that can be obtained on the identity of active species, reaction intermediates and activation/degradation phenomena. Clearly, the challenges embrace many fields: 1) catalysts can be very complex materials, comprising different, even disordered, phases; 2) it is a technique that uses synchrotron radiation, and the design of an appropriate experimental set-up requires know-how, but also synergy with a beamline team; 3) a rigorous interpretation of the XAS data requires high level of expertise to avoid easy misinterpretations, and the continuous development of new data analysis methods.
This talk aims to discuss in-situ/operando XAS studies to investigate the activity and stability of novel catalysts during electrochemical reactions in proton exchange membrane fuel cell (PEMFC) devices and during CO2 reduction. In most studies with operando XAS, electrochemical studies have been performed in liquid electrolyte cells. While instructive, the performance and stability observed in liquid electrolyte at room temperature is however never directly transferable to the performance in a PEMFC device, operating at high temperature, high current density, and with a solid-polymer electrolyte interface. This current limitation can be overcome by the design of an appropriate cell able to isolate and extract the signal coming from the area where the reactions take place.
Part of the talk will also be devoted to some time-resolved structural probing techniques to follow a reaction pathway under high temperature or pressure conditions.

M. Elmaalouf,M. Odziomek, S. Duran, M. Gayrard, M. Bahri, C. Tard, A. Zitolo, B. Lassalle-Kaiser, J.Y. Piquemal, O. Ersen, C. Boissière, C. Sanchez, M. Giraud, M. Faustini and J. Peron Nat Commun
2021, 12
, 3935

D. Karapinar, N.H. Tran, N.R. Sahraie, J. Li, D. Wakerley, N. Touati, S. Zanna, D. Taverna, L.H. Galvão Tizei, A. Zitolo, F. Jaouen, V. Mougel, M. Fontecave, Angewandte Chemie International Edition
2019, 58(42), 15098-15103

Zitolo, A.; Ranjbar-Sahraie, N.; Mineva, T.; Li, J.; Jia, Q.; Stamatin, S.; Harrington, G. F.; Lyth, S. M.; Krtil, P.; Mukerjee, S.; Fonda, E.; Jaouen, F., Nat Commun
2017,
8 (1), 957

A. Zitolo, V. Goellner, V. Armel, M. T. Sougrati, T. Mineva, L. Stievano, E. Fonda, F. Jaouen, Nature Materials
2015, 14, 937-942
Zip Membranes: The Coveted Blockade for the Vanadium Crossover in Flow Batteries
Authors: Crivellaro Giovanni , Vezzu Keti , Pagot Gioele , Lorandi Francesca , Pace Giuseppe , Gambaro Chiara , Meda Laura , Di Noto Vito 
Published: November 2022

Vanadium Redox Flow Batteries (VRFBs) are considered as a key technology in the field of large-scale energy storage systems [1, 2]. Unfortunately, their capabilities are compromised by the crossover of active species through the membrane which reduces the overall efficiency during operation and hinders the long-term capacity storage [3]. In this work, an extremely selective proton exchange material is proposed. “Zip-like” Ion Exchange Membranes (ZIEMs) are prepared by means of an acid-base reaction between the cationic and anionic functionalities of two interacting ionomers. The strong electrostatic crosslinking interactions between the two components generate an overall improvement of thermal and mechanical properties, and the permeation of vanadium ions is strongly hindered (the best performing membrane has a selectivity of 3.1⸱105 S⸱min⸱cm-3, which is almost 50 times higher than Nafion). The best performing membranes show outstanding VRFB performance with a stable coulombic efficiency (>98% at 50 mA⸱cm-2), and a retained capacity of 82% after 100 cycles compared to the 21% of the same device with a Nafion 212 membrane. The results presented here show how ZIEM family of membranes can be regarded among the best performing ion exchange membranes up-to-date.

Acknowledgements

The authors wish to thank the fruitful collaboration within the project “Development of high-selectivity ion-exchange membranes for application in next-generation redox flow batteries” funded by ENI S.p.A., contract 2500026228. In addition, the authors wish to thank the SID2020Project of the Department of Industrial Engineering, University of Padova “A New frontier in Hybrid Inorganic-Organic Membranes for Energy Con-version and Storage Devices” (Prot. BIRD201244) for funding.

References

[1] R.K. Emmett, M.E. Roberts, Recent developments in alternative aqueous redox flow batteries for grid-scale energy storage, Journal of Power Sources, 506 (2021) 230087.
[2] C. Sun, E. Negro, A. Nale, G. Pagot, K. Vezzù, T.A. Zawodzinski, L. Meda, C. Gambaro, V. Di Noto, An efficient barrier toward vanadium crossover in redox flow batteries: The bilayer [Nafion/(WO3)x] hybrid inorganic-organic membrane, Electrochimica Acta, 378 (2021) 138133.
[3] V. Di Noto, K. Vezzù, G. Crivellaro, G. Pagot, C. Sun, L. Meda, I.A. Rutkowska, P.J. Kulesza, T.A. Zawodzinski, A general electrochemical formalism for vanadium redox flow batteries, Electrochimica Acta, 408 (2022).
(Invited) A Formalism Relating the Relative Humidity to the Proton Conductivity Mechanism of Membranes
Authors: Di Noto Vito , Vezzu Keti , Lorandi Francesca , Pagot Gioele , Paddison Stephen , Zawodzinski Thomas A. 
Published: November 2022

The relationship between relative humidity of gas phase and proton conductivity in proton exchange membranes has been subject of extensive investigations [1],[2]. Herein, a theoretical framework is presented which describes proton transport in relation to stepwise equilibria that reflect the water uptake. In the proposed model, at first, the hydration process is treated as a stepwise equilibrium process, in agreement with experimental observations. Several hierarchical levels of structure evolve with increasing hydration. These levels are easily confirmed by the analysis of the electric response of perfluorinated based membranes by complex dielectric and conductivity spectra. Thus, a wide range of literature data on hydration of Nafion as a function of activity and temperature has been analyzed by means of the proposed model to extract chemical parameters diagnostic of the type of interactions characterizing the hydrophilic domains of membranes.
These parameters, which are crucial in order to modulate the ion transport phenomena in ionomers, are then introduced into the model to describe the functional dependence of conductivity on water activity in gas phase. The treatment of proton conductivity is built on the approaches commonly adopted to describe transport in solids [3]. Key proton migration phenomena appropriate to the levels of the structural hierarchy are considered. The conductivity model is used to describe a set of conductivity vs. water uptake data as a function of temperature, with data taken to exceptionally low water contents. The formalism is then used to analyze a set of data for a perfluorosulfonic acid (PFSA) membrane as a function of hydration, temperature and polymer equivalent weight. The main advantage of the proposed framework is the possibility of a straightforward application to multiple membrane types based on the energetics of water uptake. Actually, the focus on chemical interactions allows to better correlate the effects of the morphology and relaxation events of the matrix to the proton migration phenomena of the membrane.

Acknowledgements

This work has received funding from: (a) the European Union’s Horizon 2020 research and innovation program under grant agreement 881603; (b) the project ‘Advanced Low-Platinum hierarchical Electrocatalysts for low-T fuel cells’ funded by EIT Raw Materials.

References

[1] Kreuer K.D., Schuster M., Obliers B., Diat O., Traub U., Fuchs A., Klock U., Paddison S.J., Maier J. 2008 J. Power Sources
178 499-509.
[2] Maalouf M., Pyle B., Sun C.N., Wu D., Paddison S.J., Schaberg M., Emery M., Lochhaas K.H., Hamrock S.J., Ghassemi H., Zawodzinski, T.A. 2009 ECS Trans.
25 1473.
[3] A.D. LeClaire and A. Rabinovitch, 1981, J. Phys. C, 14 3863.
(Invited) Photoinduced Electron Transfer in Mechanically Interlocked Suit[3]Ane Systems
Authors: Stasyuk Anton , Stasyuk Olga , Solà Miquel , Voityuk Alexander A. 
Published: November 2022

Mechanically interlocked molecules (MIMs) attract significant attention of scientists over the past few decades due to their unusual architecture. For a long time, architectures of MIMs were represented by catenanes, rotaxanes, molecular knots, and their derivatives. Only several years ago, a new type of MIMs that do not possess interlocked rings or dumbbell shaped molecule threaded through a macroring was introduced. Suitanes – a class of MIMs, which consist of two separate components - contains a body with two or more rigid limbs protruding outwards and a close-fitting, all-in-one suit.
We present the results of computational modelling of the photoinduced processes in the recently reported by F. Stoddart two-component MIM - suit[3]ane, and similar systems with aromatic 3-fold symmetric bodies.[1] The reported suit[3]ane contains a benzotrithiophene (BTT) derivative with three n-hexyl substituents (BTT-3C6
) as a body and 3-fold symmetric pyridinium-based cage, namely HexaCage6+ (HC6+∙6PF6
-
), as a suit.
Analysis of the ground state properties of the suit[3]anes show that low LUMO of HC6+∙6PF6
-
and its ability to delocalize charge make this cage an efficient electron acceptor. The TDDFT calculations for a series of inclusion complexes (HC6+∙6PF6
-

⊃
XXX, where XXX are aromatic 3-fold symmetric bodies) revealed that the photoinduced electron transfer process is favorable not only for the complexes with strong donors, such as thiatruxene or benzotrithiophenes, but also for poor donors, such as benzotrifuran. The photoinduced charge separation in the studied complexes occurs on a picosecond time scale. The computations predicts very similar electronic properties not only for single unit of suit[3]ane but also for its aggregates.
The high stability of suit[3]anes in combination with their photoinduced electron transfer properties makes this new class of interlocked molecules promising materials for photovoltaic applications.[2]

References:

[1] J. F. Stoddart et al., J. Am. Chem. Soc.
2020, 142, 20152.
[2] A.J. Stasyuk et al., J. Mater. Chem. C, 2021, 9, 9436.

Figure 1
Determination of Individual Gibbs Energies of Ion and Electron Transfer in Electrochemical Insertion Processes
Authors: Muñoz Eduardo , López Silvana , Cáceres Gustavo , Rojas Victor , Vera Cristobal 
Published: November 2022

Based on three-phase electrode models, we study to access the Gibbs energy contributions for the transfer of ions and electrons in Prussian blue analogs since they have long life cycles and high energy efficiency. Ni[Fe(CN)6] (HCFNi) and Cu[Fe(CN)6] (HCFCu) were preliminarily synthesized by a hydrothermal process. The obtained HCFNi powders were supported on a paraffin-impregnated graphite electrode in contact with an organic electrolyte, producing solid-state oxidation-reduction electrochemical reactions, which have been monitored by cyclic voltammetry and open circuit potential measurements in the presence of potassium as intercalating ion. The results show a behavior according to the Nernst equation as the potassium ion concentration varies, with a slope of 61.2 mV/dec. These experiments make it possible to access Gibbs free energy values for both transfers separately and replicate them for different insertion ions, such as Na+ and Li+.
Figure: (Left) Open circuit potential measurements; (center) mid-peak potential measurements; and (right) cyclic voltammetry for Ni[Fe(CN)6] in potassium media.

Figure 1
(Invited) Prussian Blue Analogues as Battery Materials
Authors: Pasta Mauro 
Published: November 2022

Prussian Blue Analogues (PBAs) have gathered renewed interest recently because of their unique electrochemical properties, several of which are highly desirable for energy storage1. These intriguing properties arise from the interaction of the crystal structure with inserting ions. The general electrochemical equation for the insertion of an alkali metal into a PBA is given by:
AxPJ[RK(CN)6]1−y · wH2O + A+ + e− → Ax+1PJ[RK−1(CN)6]1−y · wH2O
where A is an alkali-metal ion, and P and R are transition-metal ions octahedrally coordinated to six cyanide ligands via the nitrogen and carbon atom, respectively (Figure 1). The value y is the fraction of vacancies in the hexacyanoferrate complex ion (the primary lattice defect). Water can also be present, both as zeolitic and coordinated to deficiently bonded metal ions at vacancies.

Figure 1: Schematic representation of the crystal structure of PBAs. The green and dark-blue atoms are transition-metal ions at the R site and P site, respectively. Gray atoms are carbon and light-blue atoms are nitrogen.

In my talk, I will show how these exciting properties are linked to the structural diversity of PBAs2 and how their chemistry can be tuned to adapt their electrochemistry to a variety of energy storage applications3,4, with focus on K-ion batteries5–7.

References

Hurlbutt, K., Wheeler, S., Capone, I. & Pasta, M. Prussian Blue Analogs as Battery Materials. Joule vol. 2 1950–1960 (2018).

Cattermull, J., Pasta, M. & Goodwin, A. L. Structural complexity in Prussian blue analogues. Materials Horizons 8, 3178–3186 (2021).

Wheeler, S., Capone, I., Day, S., Tang, C. & Pasta, M. Low-Potential Prussian Blue Analogues for Sodium-Ion Batteries: Manganese Hexacyanochromate. Chemistry of Materials 31, 2619–2626 (2019).

Hurlbutt, K., Giustino, F., Pasta, M. & Volonakis, G. Electronic Structure and Electron-Transport Properties of Three Metal Hexacyanoferrates. Chemistry of Materials 33, 7067–7074 (2021).

Fiore, M. et al. Paving the Way toward Highly Efficient, High-Energy Potassium-Ion Batteries with Ionic Liquid Electrolytes. Chemistry of Materials 32, 7653–7661 (2020).

Dhir, S., Wheeler, S., Capone, I. & Pasta, M. Outlook on K-Ion Batteries. Chem 6, 2442–2460 (2020).

Cattermull, J. et al. Revealing the structural complexity of Prussian blue analogues: the case of K2Cu[Fe(CN)6]. ChemRxiv (2022) doi:10.26434/chemrxiv-2022-zr5nn.

Figure 1
An Incremental Double Layer Capacitance of a Novel Ring-Disk Electrodes Array for Avidin/Strepavidin Sensing
Authors: Xie Qiuzhe , Lin Chih-Ting 
Published: November 2022

Electric double layer (EDL) is established by ion redistribution at a solid-liquid interface. This ion redistribution electrically screens solid-surface charges and renders the interface to neutral. As a result, EDL is highly related to the surface potential, and a capacitor or constant phase element (CPE) is always employed to model the relationship between EDL and surface potential. According to this mechanism, diverse applications have been developed by controlling EDL via modulate potential fields or surface modifications. However, most of previous methods are sophisticated and hard to implemented as an in-situ monitoring method. To address this demand, we proposed a ring-disk electrode array (RDA) architecture to detect the changes of EDL capacitance between ring and disk electrode.
Based on the proposed architecture, the surface potential will change while the biomolecular is immobilized onto to the vertical nanogap. This effect is verified by immobilizing different charged functional groups and the correlation between the surface potential and incremental-capacitance variance is also demonstrated. Based on this effect, the application for Avidin detection is implemented. The detectable range for Avidin measurement is from 100 fg/ml to 1 ng/ml.
Based on this work, the incremental double-layer capacitance of a planar nanogap structure can provide a simple and reliable method for surface potential monitoring and can be used for different chemical and clinical examinations.

Figure 1
Efficient Sensor Calibration Via Machine Learning-Based Resampling Methods
Authors: Ding Alison , Wang Jiacheng , Hang Yingjie 
Published: November 2022

It remains a challenge to accurately and precisely calibrate a sensor in an experimentally-efficient manner. The calibration task at hand is to quantify the functional relationship between the sensor’s response (denoted as y) and the target analyte concentration (denoted as x) based on laboratory experiments. In practical use, the sensor’s mathematical calibration model needs to be coupled with the device to make inference regarding the concentration of the analyte in an environment based on the observed sensor response. It is critical to provide a single-value estimate for the analyte concentration, as well as to quantify the uncertainty of the target estimate (i.e., to provide the possible range of the underlying concentration level).
However, classic statistical methods are not able to provide valid inference on the target quantity of interest due to the following difficulties in sensor calibration. First, not only the typical forward modeling but also the inverse estimation is involved. The former refers to the generation of a calibration model functionally relating the analyte concentration to the sensor response (x→y) based on experimental data; The latter concerns the use of the calibration model in practical setting to obtain from the observed response the estimation of the unknown concentration (y→x). Second, the variability of the sensor responses tends to be heterogeneous as opposed to homogeneous, which is an assumption that classic statistical methods rely on.
In light of the above, a computational resampling method was adapted in this work to address the machine learning (ML)-based inference issues (i.e., the uncertainty quantification of the estimated analyte concentrations). Built on the inference capability, a two-stage experimental design procedure was developed to guide the efficient sampling of calibration data via laboratory experiments.
The ML-based inference and experimental design methods are integrated in the chemometric calibration procedure, which was applied on a simulated biosensor to demonstrate its efficiency over traditional methods. The sensor simulator is developed from the real experimental data for a paper-based lateral flow strip (PLFS) designed to measure in blood the diagnosis biomarkers for traumatic brain injury. PLFS is finding increasing applications in detection of various diseases in point-of-care testing settings.

Figure 1