bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass-Manufacturing of Sub-Micron Coated Metal Coils for Scaling-up the Production of Electrochemical Devices
Authors: Bernuy-Lopez Carlos , Proch Sebastian Karl , Bexell Ulf , Westlinder Jörgen 
Published: May 2020

Sandvik Surface Technology is a production unit within AB Sandvik Materials Technology (SMT). The business area SMT belongs to the Sandvik group and is a world-leading manufacturer of advanced stainless steels and special alloys for the most demanding industries. Sandvik Surface Technology offers a portfolio of cost-effective coated metal strip for applications such as batteries, fuel cells and electrolyzers.
Metal coils are coated with sub-micron metal coatings according to customer specifications regarding composition and thickness of both the substrate and the coating in a Physical Vapour Deposition process through the roll-to-roll coating lines developed by Sandvik (Figure 1). This pre-coated solution reduces some of the handling that comes with batch coating of individual components and provides an outstanding opportunity for the cost-effective industrial mass production of electrochemical devices.
Figure 1. Image of one of the coating lines developed by Sandvik in Sandviken (Sweden). The final coated metal coils are also shown.
The Surface Research group at SMT Strategic Research provides vital knowledge and understanding of such a complex coating process which facilitates the development of the above-mentioned products. Scientific questions such as the development of the adequate coating and substrate composition for every electrochemical device, the influence of nanometric defects on the performance of the electrochemical device or the formation of stable and protective layers against corrosion after more than 20,000 h of operation are addressed and will be shown in this work.

Figure 1
(Invited) Earth Abundant Electrocatalysts for Alkaline Water Electrolysis
Authors: Zhao Chuan 
Published: May 2020

The increasing demands for clean energy have triggered tremendous research interests on electrochemical energy conversion and storage systems with minimum environmental impact. Hydrogen holds the promise as energy carriers for global scale storage of renewable energy, e.g., solar and wind, enabling the continuous usage of these diffusive and intermittent energy sources when used together with fuel cells.Nevertheless, the widespread application of hydrogen technology has been severely constrained by the use of precious metal catalysts, such as oxides of ruthenium and iridium for the oxygen evolution reaction (OER), and platinum for the hydrogen evolution reaction (HER) and oxygen reduction reactions (ORR). Furthermore, electrochemical CO2 reduction reactions (CRR) and nitrogen reduction (NRR) provide alternative pathways for hydrogen storage and transport. These emerging technologies also call for highly efficient and selective catalysts to promote their industrial viabilities.
This presentation shows our efforts in developing non-precious metal-based electrocatalysts for alkaline water electrolysis, as well as our strategies for enhancing these catalysts to a level comparable to that of precious metal catalysts. The commercialisation of some our catalysts in hydrogen industry also will be highlighted.
Tuning Fundamental Properties of Ir-Based Materials to Enhance Their Electrocatalytic Performance in the Oxygen Evolution Reaction
Authors: Kasian Olga , Schweinar Kevin , Li Tong , Mayrhofer Karl J. J. , Gault Baptiste 
Published: May 2020

The oxygen evolution reaction (OER) underpins electrochemical technologies for hydrogen generation [1]. The sluggish kinetics of the OER and the instability of most of the anode materials hinder widespread application of proton exchange membrane water electrolyzers (PEMWE). Up to now, only iridium-based catalysts meet the necessary requirements and are currently employed in PEMWE [2]. Despite the scarcity and high cost of iridium, its relatively high reactivity and superior stability make it irreplaceable to optimize the durability of the electrolyzer. Understanding what governs the electrocatalytic activity as well as the long-term stability of iridium is crucial for the development of novel catalysts that will enable efficient energy conversion and storage technologies. Gaining this knowledge requires establishing the correlation between the atomic-scale structure of the catalysts, their electronic properties and the mechanisms of the OER and other side reactions that lead to the material’s degradation.
In this presentation, I give an overview of our recent results, with a special focus on the mechanisms of the reactions ongoing at the surface of an array of iridium-based anodes during the OER [2-4]. The mechanistic insights are obtained from combination of X-ray photoelectron spectroscopy, online electrochemical mass spectrometry, electron microscopy and atom probe tomography. During the presentation, specific structural and compositional features that we recently revealed are responsible for high reactivity and/or instability of catalytic systems will be discussed in detail [4]. In addition several approaches to improve both the reactivity and the stability will be proposed, and can serve as guiding principles for the development of materials with superior electrocatalytic performance towards the OER.
[1] V. R. Stamenkovic, D. Strmcnik, P. P. Lopes and N. M. Markovic, Nat. Mater., 16 (2017) 57.
[2] T. Li, O. Kasian, S. Cherevko, et al., Nat. Catalysis 1 (2018) 300.
[3] O. Kasian, J.-P. Grote, S. Geiger, S. Cherevko, K. J. J. Mayrhofer, Angew. Chem., Int. Ed., 57 (2018) 2488.
[4] O. Kasian, S. Geiger, T. Li, J-P. Grote, K. Schweinar, S. Zhang, C. Scheu, D. Raabe, S. Cherevko, B. Gault, K. Mayrhofer, Energy & Environmental Science (2019), DOI: 10.1039/C9EE01872G.
Nano-Structured Transition Metal Phosphides As an Efficient Electrocatalysts for Oxygen Evolution Reaction
Authors: Poureshghi Fatemeh , Seland Frode , Sunde Svein 
Published: May 2020

Although the catalytic activity of transition metal phosphide compounds, such as dinickel phosphide (Ni2P), have been known for over half a century. they have only recently been investigated for heterogeneous (electro)catalysis. In 1995, it was shown that the performance of electrodeposited amorphous Ni–P electrodes (ca. 3 wt% phosphorous content) toward the HER in alkaline conditions can be orders of magnitude higher than that of Ni electrodes [1]. Detailed structural analysis of these transition metal phosphide materials had not been discussed in such early works. it was only very recently realized that the transition metal phosphides have reemerged as one of the most promising classes of earth-abundant inorganic electrocatalysts.
Depending on the P:Ni molar ratio and the reaction temperature, different phases have been reported for Ni-phosphide compounds. Among all NixPy phases, Ni12P5 nanoparticles shows high electrocatalytical activity toward OER due to its unique crystallite structure and the higher concentration of nickel in this phase. which enables the formation of an amorphous NiOOH/Ni(OH)2 shell on a modified multiphase with a disordered phosphide/phosphite core [2]. However, the synthesis of Ni12P5 is quite challenging and a small deviation in the P:Ni molar ratio will result in Ni2P phase.
In this study, pure phase of Ni12P5 and Ni0.9Fe0.1P colloidal nanoparticles have been synthesized by the reaction of [Ni(acac)2] with oleylamine (OA) and trioctylphosphine (TOP) reactants. OA is the reducing agent and thus controls the nucleation rate and TOP acts a source of phosphorus and also provides surface stabilization for tuning particles size. This synthesis results in monodisperse nanoparticles of diameter approximately 12nm [3]. These Ni12P5 and Ni0.9Fe0.1P nanoparticles show enhanced electrocatalytical activity toward OER in 0.1M KOH electrolyte, resulting in a current density of 10 mA cm−2 with overpotentials at 0.304 V and 0.20 V respectively.

References:

[1] Yu, F., Zhou, H., Huang, Y., Sun, J., Qin, F., Bao, J., ... Ren, Z. (n.d.). metal phosphide catalyst for overall water splitting, (2018), 1–9.
[2] Menezes, P. W., Indra, A., Das, C., Walter, C., Göbel, C., Gutkin, V., ... Driess, M. (2017). Uncovering the Nature of Active Species of Nickel Phosphide Catalysts in High-Performance Electrochemical Overall Water Splitting. ACS Catalysis, 7(1), 103–109.
[3] Muthuswamy, E., Savithra, G. H. L., & Brock, S. L. (2011). Control of Phase, Size, and Morphology in Nickel Phosphide Nanoparticles, (3), 2402–2411.
Microwave-Assisted Hydrothermal Synthesis of Transition Metal Doped ZnO Nanoparticles and Their Electrocatalytic Activity for Water Oxidation
Authors: Nishiumi Nobuyuki , Harada Yuya , Sun He , Shiroishi Hidenobu , Matsushima Yuta , Stadler Philipp , Yoshida Tsukasa 
Published: May 2020

Among various metal oxides previously tested, Co3O4 is known to be one of the best catalysts for oxygen evolution reaction (OER). In this study, doping of Co ions into nanocrystals of zinc oxide (ZnO) has been achieved by microwave (MW) assisted hydrothermal reaction to form catalytic surface sites for OER combined with highly conductive and stable ZnO for flexible catalyst design and potential enhancement of the catalytic activity.
MW-assisted hydrothermal reaction has successfully achieved synthesis of Co-doped ZnO nanocrystals at a low reaction temperature of 160ºC and in a short reaction time of 30 min. Partial replacement of 4-coordinated Zn(II) ions of ZnO with Co(II) ions up to about 10at% has been suggested from evaluation of the products by UV-Vis absorption spectra, morphological observations and X-ray diffraction. The higher addition of Co resulted in its phase-separated precipitation as Co(OH)2. While mesoporous electrode processed from ZnO nanocrystals was totally inactive for water oxidation, that of Co-doped ZnO exhibited a good catalytic activity to achieve about 1 mA cm-2 current of OER with an overvoltage of 0.545 V in a neutral aqueous KCl solution, which in fact was far superior to a Co3O4 electrode known to suffer from its limited conductivity. The doped Co ions are only expected to act as reaction centers for charge transfer on the very surface in contact with the electrolyte, while ZnO acts as a highly conductive and chemically stable host matrix to support the catalyst.
Simple Deposition of Metal Salts on Graphene Oxide As Novel Water Oxidation Catalysts
Authors: Fruehwald Holly M , Moghaddam Reza B. , Zenkina Olena V , Easton E. Bradley 
Published: May 2020

As populations grow world-wide, there is an ever increasing need for more sustainable and renewable energy sources to keep up with the high demand of energy needed. One promising high energy source is the water splitting reaction where water is split into hydrogen and oxygen gas. However, the materials usually required to facilitate this reaction are often rare and expensive earth metals such as iridium. Thus, the focus has been on using Ir-free materials as a cost-efficient alternative. One such metal is ruthenium, Ru is ideal as it has many oxidation states to help facilitate the water splitting reaction, to aid in reducing the over potentials[1]. Yet, ruthenium-based materials have problems such as being prone to stability issues in acidic media, high over potentials and slow kinetics, so improvements should be made on catalyst design to lower over potentials and improve stability. On the other hand, Ru can also be considered a somewhat rare metal, thus further inexpensive and non-precious metals should be used in the future designs of these materials to lower cost without sacrificing activity.
In this work we synthesized graphene oxide electrochemically from a graphite rod source, using a simple, low cost method[2]. Graphene was chosen to stabilize the nanoparticles and enhance the conductivity of the resulting materials. Metal nanoparticles from either a Ru(III) or Ru(VII) salt precursor were deposited on the surface of the graphene oxide using a facile method of preparation to afford a ca. 3% metal loading on the graphene oxide. The materials were examined electrochemically in acidic media for the water oxidation reaction, where we observed low over potentials for the reaction and high stability during prolonged testing[3]. Now, we are comparing the activity of these metals and other non-precious metals for their water oxidation activity in basic electrolyte. These novel metal nanoparticles stabilized on a graphene could aid in the development of cost efficient and sustainable materials for the future of renewable energy technologies.
[1] Kamdar, J.M.; Grotjahn, D.B. Molecules
2019, 24, 494.
[2] Liu, J.; Poh C. K.; Zhan, D.; Lai, L; Lim, S. H.; Wang, L.; Liu, X.; Sahoo, N. G.; Li, C.;
Shen, Z.; Lin, J. Nano Energy. 2013, 3, 377-386
[3] Fruehwald, H. M.; Moghaddam, R. B.; Zekina, O. V.; Easton, E. B., Cat. Sci. Technol.
2019, 9, 6547-6551
Electrospun Ruthenium-Cobalt Mixed Oxide Nanotubes As a Highly Active and Stable Electrocatalyst for Oxygen Evolution Reaction
Authors: Yu Areum , Lee Chongmok , Kim M. H. , Lee Youngmi 
Published: May 2020

Proton exchange membrane (PEM) water electrolysis using acidic electrolytes has many positive aspects of high operating current densities, gases with high purity, and high efficiency. However, it has disadvantages such as noble electrocatalysts required. Metal oxides (RuO2, IrO2) known as efficient electrocatalysts for anodic oxygen evolution reaction (OER) are scarce and expensive. Therefore, a substantial research effort has been devoted to the development of economical electrocatalysts with high performance and durability.
In this presentation, bimetallic RuCo mixed oxide nanotubes with various relative compositions are synthesized by electrospinning and calcination in expectation of the synergistic effect and cost cutting. The hollow morphologies, compositions and atomic distribution of the prepared RuCo mixed oxide nanotubes are characterized by field-emission scanning electron microscopy (FE-SEM) equipped with an energy disperse X-ray spectrometer (EDS) and transmission electron microscopy (TEM). Through X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis, the sizes of unit cell of RuO2 rutile structure and Co3O4 cubic structure are found to be changed due to the mutual substitution. Electrochemical acitivities of diverse RuCo mixed oxide nanotubes for OER are studied with rotating disk electrode (RDE) voltammetry in 1 M HClO4 aqueous solution. Tafel slopes are obtained from the corresponding voltammetric curves for OER to comprehensively elucidate the kinetics of OER. The onset potential of RuCo mixed oxide nanotubes is determined precisely using scanning electrochemical microscopy (SECM). This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Science, ICT and Future Planning (NRF-2017R1A2A2A14001137).
Enhanced Performance and Durability of Low Pt- and Ir-Loading PEM Water Electrolysis
Authors: Fujita Mitsuharu , Konaka Saki , Goto Hiroki , Arima Ikkei , Tada Tomoyuki 
Published: May 2020

In recent years, water electrolysis for hydrogen production is considered as a key technology to greenhouse gases reduction. In particular, PEM water electrolysis has the advantages of high efficiency, high current density and responsiveness to renewable energies. On the other hand, since a large amount of Pt and Ir metals are used in the PEM electrolyzer, it is necessary to reduce the amount of Pt and Ir metal used for the growth market in the future.
In this study, we focused on the low Pt and Ir loading CCM with SA100(Ir catalyst) and TEC10E50E(Pt catalyst). CCMs were prepared by splay method, the SEM images of cross-section are shown in Figure. CCMs with different configurations for catalysts, ink process, and catalysts loadings were studied using particle size distribution analyzer, polarization curves, durability, and other electrochemical methods. Ir Oxide should behave two roles in the catalyst layer: conductor and catalyst. In the case of CCMs with controlled ink particle size, the cross-section images and IV performance were improved. Catalyst loading reduction partially improved the polarization curves, it had a negative effect on durability.

Figure 1
High Performance and Durable Membrane Electrode Assemblies with Binder-Free Plasma Sprayed Electrodes and Nanocomposite Membranes for Anion Exchange Membrane Electrolyzer
Authors: Razmjooei Fatemeh , Kaur Jasneet , Zarrin Hadis , Gago Aldo Saul , Ansar Syed-asif , Friedrich Andreas K 
Published: May 2020

Hydrogen production via water electrolysis using electricity from renewable power sources is a promising method for storing energy in a large scale. Anion exchange membrane (AEM) electrolyzers have the potential for decreasing the hydrogen cost produced by renewables due to use of non-noble materials and inexpensive components for the membrane electrode assembly (MEA). This work demonstrates a highly active and durable MEA for AEM electrolysis using binder-free atmospheric plasma sprayed (APS) RANEY®-type nickel and RANEY®-type nickel-molybdenum electrodes,[1,2] as anode and cathode, respectively in combination with robust two-dimensional hexagonal boron nitride (h-BN)-based anion exchange membranes, nanocomposed with either polyvinylidene fluoride (PVDF) or polyvinyl alcohol (PVA). In this present work, various AEMs with different ionic conductivity and thickness, M1: High-loaded h-BN nanocomposite with PVDF or HL-BN-PVDF (0.23 Scm-1 and 125 mμ), M2: low-loaded h-BN nanocomposite with PVDF or LL-BN-PVDF (0.19 Scm-1 and 80 mμ) and M3: high-loaded h-BN nanocomposite with PVA or HL-BN-PVA (0.36 Scm-1 and 45 mμ) have been used. Three MEAs were fabricated using three membranes of HL-BN-PVDF, LL-BN-PVDF and HL-BN-PVA placed between two APS electrodes denoted as The MEA1, MEA2 and MEA3, respectively, and tested in single AEM electrolyzer cells. The tests are carried out in 1M KOH at 60 °C. As expected, the highest current, 2.6 Acm-2, at 2 V is achieved with MEA3, while MEA2 and MEA1 reached 2.95 and 3 A cm-2, respectively. The performance of AEM water electrolysis with the MEA3 is found to be slightly better than the MEA with the same electrode package but commercial membrane from Fumasep (2.71 Acm-2 at 2.0 V). The stability of the cell with MEA3 is tested under the constant load of 0.5 A cm-2 for 250 h showing negligible degradation. This can be attributed to the high mechanical and chemical stability of the membrane and low dissolution of anodic electrode. Furthermore, the lack of binders or ionomers in the APS electrodes avoids irreversible oxidation reactions of the polymer that can lead to voltage loss over time [3]. Thus, APS electrodes combined with stable nanocomposed (h-BN)-based membranes can potentially lower the cost of the hydrogen produced by water electrolysis.
1. Razmjooei, R. Reißner, A. S. Gago, and A. Ansar, ECS Transactions, 92 (8) 689-702 (2019).
2. Wang, T. Weissbach, R. Reißner, A. Ansar, A. S. Gago, S. Holdcroft, K. A. Friedrich, ACS
Appl. Energy Mater. DOI: 10.1021/acsaem.9b01392 (2019).
3. Li, I. Matanovic, A. S. Lee, E. J. Park, C. Fujimoto, H. T. Chung, and Y. S. Kim, ACS Appl. Mater. Interfaces, 11 (10) 9696-9701 (2019).
Fiber-like Structure on the Proton Exchange Membrane Created By Simultaneous Magnetron Sputtering and Plasma Etching in Role of a Catalyst Support in Water Electrolyzers
Authors: Kúš Peter , Hrbek Tomáš , Yakovlev Yurii , Novakova Jaroslava , Matolin Vladimír , Matolínová Iva 
Published: May 2020

The increasing amount of installed power capacity from wind and solar power plants puts high demand on reliable and scalable system, capable of storing the energy during the overproduction and releasing it in times of deficit. The concept of hydrogen economy seems to be an interesting alternative in this regard. It is built around the conversion of electricity into H2 in times of energy overproduction and its subsequent utilization in various different ways, such as converting back to electricity on-site via fuel cells, injecting into the existing natural gas network, processing as a commodity or dispatching as an energy vector. Regardless of which pathway for H2 is ultimately chosen, the key inseparable technology necessary for the concept of hydrogen economy to function remains the water electrolysis. Proton exchange membrane water electrolyzers (PEM-WE) are arguably the most suitable for industrial scale-up. Still there are challenges that need to be solved, should the technology enter the mass production. One of the most crucial aspects is the need of lowering the amount of iridium on the anode of PEM-WE. It is currently the only sufficiently active catalyst which withstands the aggressive conditions during the oxygen evolution reaction (OER). Reducing Ir loading through its dispersion over the catalyst support, a method adopted from fuel cell industry, is not trivial since it is hard to find inexpensive, corrosion-resistant and conductive material in form of nanoparticles.
In this work, we present and discuss an innovative, yet very straightforward and industrially adaptable approach on how to circumvent the above mentioned problem. The proposed approach is based on the utilization of magnetron sputtering. The novelty of our patented approach is in simultaneous plasma etching of the PEM and deposition of CeOx thin film onto its surface. The CeOx layer serves as a masking element - the loss of material is hindered at the places with its sufficient coverage; in contrast, unprotected places are being continually etched out. This result in formation of a fiber-like structure with cross-sectional dimensions much smaller than their height. The modified surface of the PEM itself is therefore sufficiently large to carry the subsequently deposited thin-film catalyst completely on its own. Our study comprises characterization of the modified PEM morphology, electrochemical active surface area determination via rotating disk electrode and in-cell PEM-WE performance testing, including electrochemical impedance spectroscopy.

Figure 1
Transient Oxygen Reduction Reaction Kinetics in PEM Fuel Cell
Authors: Yarlagadda Venkata , Gu Wenbin , Arisetty Srikanth , Lenert Andrej , Kongkanand Anusorn 
Published: May 2020

Oxides on the surface of an electrocatalyst inhibit oxygen reduction reaction (ORR) activity at high potentials. Although this process has been described for Pt/Vulcan electrocatalysts by an ORR kinetic model1, there is an opportunity to improve the existing model to accurately predict performance loss under non-standard temperature, relative humidity and transient operating conditions. Also, the established kinetic model does not accurately predict the performance for Pt-alloy electrocatalysts.
Here, we conducted time-resolved measurements of ORR kinetics for both Pt and Pt-alloy electrocatalysts under various temperature and relative humidity conditions in a PEM fuel cell. The oxide coverage was measured in a H2-N2 environment using cyclic voltammetry. ORR polarization measurements were conducted in H2-O2 environment. The experimental data was used to develop a kinetic model that depends on the oxide coverage, which showed improved prediction capability based on dynamic polarization measurements of Pt and Pt-alloy catalysts.
This work was partially supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy under grant DE-EE0007271.

Reference

1. P. Subramanian, T. A. Greszler, J. Zhang, W. Gu, and R. Makharia, Journal of The Electrochemical Society, 159 (5), B531-B540 (2012)