bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxygen Reduction Reaction on Nitrogen and Cobalt Modified Silicon Carbide Derived Carbon in Acidic Media
Authors: Teppor Patrick , Jäger Rutha , Härk Eneli , Joost Urmas , Tallo Indrek , Paiste Päärn , Kirsimäe Kalle , Lust Enn 
Published: February 2020

Active research is currently being done to study and develop alternative cathode catalyst materials for the purpose of lowering the oxygen reduction reaction (ORR) overpotential in polymer electrolyte membrane fuel cells. In this regard, carbon materials modified with nitrogen and a non-platinum group metal, either iron or cobalt, have shown promising results.[1-3]
In this work, non-platinum group metal and nitrogen type ORR catalysts were successfully synthesized via a simple solution-based method using a silicon carbide derived carbon support, cobalt and different nitrogen precursors, namely 2,2’-bipyridine and 1,10-phenanthroline.[2]
The characteristics of the resulting materials were studied using various physical and electrochemical methods. The main physical characterization was done by low-temperature nitrogen sorption analysis, X-ray photoelectron spectroscopy and inductively coupled plasma mass spectrometry. The electrochemical characterization was done in an acidic environment using the rotating disc electrode and cyclic voltammetry methods carried out in a three-electrode electrochemical cell.
According to the electrochemical measurements, modifying the carbon support with cobalt and nitrogen increased the half-wave potential value of the ORR curves by around 460 mV. Furthermore, the achieved ORR activities of both synthesized catalyst materials were comparable to the activities of similar catalysts presented in the literature. The ORR stabilities of both materials were additionally studied and the calculated activity decrease speeds were found to be somewhat smaller than those reported for similar materials.[3]
[1] H. T. Chung, D. A. Cullen, D. Higgins, B. T. Sneed, E. F. Holby, K. L. More, P. Zelenay. Science 357 (2017) 479.
[2] F. Roncaroli, E. S. D. Molin, F. A. Viva, M. M. Bruno, E. B. Halac. Electrochimica Acta, 174 (2015) 66.
[3] S. Li, L. Zhang, H. Liu, M. Pan, L. Zan, J. Zhang. Electrochimica Acta 55 (2010) 4403.
In-Situ Electrochemical X-Ray Diffraction of Pt Oxidation and Reduction in Hydrogen Fuel Cells
Authors: Martens Isaac , Drnec Jakub , Blanco Maria Valeria , Pusa Janne , Honkimäki Veijo , Wilkinson David P. , Bizzotto Dan 
Published: February 2020

The commercialization of proton exchange membrane (PEM) fuel cells has increasingly demanded lower precious metal catalyst loadings. A better understanding of platinum nanoparticle degradation mechanisms and electrochemistry will be essential in preserving fuel cell performance over increased device lifetimes. In-situ synchrotron x-ray diffraction/scattering is a powerful tool for characterizing commercial catalyst layers in an electrochemical cell1-2. Recent advances in hardware presently allow time-resolved scattering measurements and diffractive imaging3 without compromising electrochemical experiments. New cell designs4 greatly improve the ease and flexibility of measuring membrane electrode assemblies under environmental conditions and Pt loadings relevant for fuel cell operation and degradation.
The structural effects and kinetics of platinum electrochemistry on nanoparticles can be directly probed using x-ray diffraction. The evolution of nanoparticle strain, atomic ordering, oxidation, and dissolution are monitored in the presence of adsorbing molecular species under potential control. We show how by monitoring Pt particle size, and Pt lattice strain, it is possible to deconvolute chemical and electrochemical steps in the mechanism of Pt oxidation and reduction. Measurements using conventional single crystal and half cell experiments are compared with x-ray diffraction on an operating PEM fuel cell cathode. Several differences in surface chemistry between these cell configurations are detected, which is directly relevant to the development of better accelerated aging and stress-testing protocols.
Particular attention has been given towards developing these advanced synchrotron techniques as useful tools for the non-specialist. Recent advances improving the accessibility of in situ diffraction for the electrochemical community are discussed.
Figure 1. X-ray transparent half-cell suitable for high-energy x-ray diffraction of membrane electrode assemblies (left). X-ray powder diffractogram obtained from fuel cell cathode during the oxygen reduction reaction (right).

Imai, K. Izumi, M. Matsumoto, Y. Kubo, K. Kato and Y. Imai. J. Am. Chem. Soc., 2009, 131 (17), pp 6293–6300

K. Sasaki, N. Marinkovic, H.S. Isaacs, and R.R. Adzic. ACS Catal., 2016, 6 (1), pp 69–76

F. Reikowski, T. Wiegmann, J. Stettner, J. Drnec, V. Honkimaki, F. Maroun, P. Allongue, O.M. Magnussen. J. Phys. Chem. Lett., 2017, 8 (5), pp 1067–1071

B. Pinaud, A. Bonakdarpour, L. Daniel, J. Sharman and D.P. Wilkinson. J. Electrochem. Soc. 2017, 164 (4), pp F321-F327

Figure 1
Annealing Effect of Nafion-Propyl-1,2,3-Triazole Membrane By Autoclave Solution Processing
Authors: KIM Je-Deok , Ghil Lee-Jin , Ohira Akihiro 
Published: February 2020

Keywords: Autoclave solution processing, Nafion-propyl-1,2,3-triazole membrane, Annealing treatment, PEMFCs
Proton exchange membrane fuel cells (PEMFCs) are one of the most promising candidates among the various types of fuel cell systems due to their applications and mode of operation. There is a need for improvements to perfluorinated polymers such as lower membrane cost, high conductivity at high temperature (> 90°C) and low humidity, etc.
We prepared various acid-base composite membranes, and base compounds were found to be well incorporated into the nanostructure of sulfonic acid phase in Nafion polymers [1-9]. A propyl-1,2,3-triazole was synthesized by a perfluorosulfonic acid (PFSA) polymer solution (Nafion) with propyl alcohol using room temperature (RT) and autoclave (AC) solution processing [5-8]. Both the blend membranes were flexible. However, the Nafion-propyl-1,2,3-triazole membrane was required more improved chemical and mechanical stability. An annealing treatment was conducted at the temperature of 180 oC for 3 h. The annealing processing is responsible to increase a crystallinity in the nanostructure of pristine membrane. The annealed membrane showed more improved property than pristine in the chemical, mechanical, and crystallinity.
Acknowledgements
This work was partially supported by the MEXT program for development of environmental technology using nanotechnology.
References
[1] J.-D. Kim, Y. Oba, M. Ohnuma, M.-S. Jun, Y. Tanaka, T. Mori, Y.W. Choi, Y.-G. Yoon, J. ECS, 2010; 157: B1872-B1877.
[2] J.-D. Kim, Y. Oba, M. Ohnuma, T. Mori, C. Nishimura, I. Honma, Solid State Ionics, 2010; 181: 1098-1102.
[3] J.-D. Kim, T. Mori, S. Hayashi, I. Honma, J. ECS, 2007; 154: A290-A294.
[4] J.-D. Kim, M. Onhuma, C. Nishimura, T. Mori, A. Kucernak, J. ECS, 2009; 156: B729-B734.
[5] J.-D. Kim, M.-S. Jun, C. Nishimura, Y.-W. Choi, ECS Transactions, 2011; 35: 241-250.
[6] J.-D. Kim, M.-S. Jun, M.L. Divona, Fuel Cells, 2013; 13: 65-71.
[7] J.-D. Kim, M.-S. Jun, H.-W. Rhee, ECS Transactions, 2013; 58: 271-282.
[8] J.-D. Kim, L.-J. Ghil, M.-S. Jun, J.-K. Choi, H.-J. Chang, Y.-C. Kim, H.-W. Rhee, J. ECS, 2014; 161: F724-F728.
[9] J.-D. Kim, M.-S. Jun, Materials Science forum, 2014; 783-786: 1692-1697.
(Invited) Influence of Mechanical Stress on Lithium Chemical Potential in Lithium Ion Battery Electrodes
Authors: Amezawa Koji , Funayama Keita , Kimura Yuta , Mahunnop Fakkao , Nakamura Takashi , Kuwata Naoaki , Kawamura Junichi , Kawada Tatsuya 
Published: February 2020

In solid-state ionic devices, such as all-solid-state lithium ion batteries (ASSLIBs) and solid oxide fuel cells (SOFCs), mechanical stress is introduced at the electrode/electrolyte hetrointerfaces due to differences in the crystal structures and the chemical/thermal expansion coefficients. A mechanical strain at the heterointerface might affect thermodynamic and kinetic properties of the electrodes and the electrolyte, resulting in the performance deterioration or improvement of the devices. Although such a so-called “mechano-electro-chemical coupling effect” has been empirically demonstrated by many researches, the origins of the effect are not fully understood so far.
In this presentation, we will discuss the influence of mechanical stress on thermodynamic properties of solid-state ionic materials. As a model case, lithium chemical potential in electrode materials for ASSLIBs under mechanical stress was investigated. A dense thin film electrode of LiCoO2, Li2MnO4 or LiFePO4 was deposited on a plate of solid-state lithium ion conductors, and the variation of the lithium chemical potential in the electrode was evaluated by measuring electromotive force under compressively- and tensely-strained conditions. Electromotive force accompanied by mechanical strain could be clearly observed, demonstrating a “mechano-electro-chemical coupling effect”. The influence of mechanical stress was different depending on the kinds of electrode material. The observed change in the electromotive force could be thermodynamically related to the lithium partial molar volume of the electrodes.
Sustainable and Highly Robust Anodic C,C-Cross-Coupling Reaction of Phenols
Authors: Riehl Barbara , Waldvogel Siegfried R. 
Published: February 2020

Electroorganic synthesis is a highly attractive technique to synthesize non-symmetric biphenols. These substances offer a unique structural motif in natural products and are important ligands for catalysts.[1] Typically, cross-coupling reactions need expensive transition-metal catalysts for the construction of biphenols.[2] Furthermore, commonly used methods require leaving groups or oxidizers. This leads to significant amounts of reagent waste during these cross-coupling reactions.
We established efficient pathways for the C,H activation cross-coupling to non-symmetric biphenols with tolerance of broad substitution pattern and a broad range of current density[3]. In this method, reagent waste is significally avoided due to electrons being the only reagent. Efficient and straightforward electro-organic reactions are highly attractive and sustainable.[4] Therefore, our developed method is ecological as well as economic and represents an inherently safe, and easily scalable alternative synthetic approach, which is superior to other oxidizers.[5]
References:
[1] (a) G. Bringmann, T. Gulder, T. A. M. Gulder, M. Breuning, Rev.
2011, 111, 563–639; (b) J. M. Brunel, Chem. Rev.
2005, 105, 857–898.
[2] (a) L. Ackermann, Modern Arylation Methods, Wiley-VCH, Weinheim, 2009; b) G. Dyker, Handbook of C-H Transformations, Wiley-VCH, Weinheim, 2005.
[3] Wiebe, B. Riehl, S. Lips, R. Franke, S. R. Waldvogel, Sci. Adv.
2017, 3:eaao3920.
[4] Elsler, D. Schollmeyer, K. M. Dyballa, R. Franke, S. R. Waldvogel, Angew.
Chem.
2014, 126, 5311–5314; Angew. Chem. Int. Ed.
2014, 53, 5210–5213.
[5] Riehl, K. M. Dyballa, R. Franke, S. R. Waldvogel, Synthesis
2017, 49, 252–259.

Figure 1
Electron Transfer Reactions at Liquid-Liquid Interfaces
Authors: Girault Hubert H , Gschwend Gregoire , Peljo Pekka , Olaya Astrid 
Published: February 2020

Liquid-liquid interfaces can be polarised to carry out charge transfer reactions, in particular electron transfer (ET) reactions between a hydrophilic and a lipophilic redox molecule. These reactions can be studied by classical electrochemical methods such as cyclic voltammetry.
By combining spectroscopic time resolved techniques such Surface Second Harmonic Generation with electrochemical methods, we have studied photo-initiated electron transfer reactions between adsorbed porphyrins and redox quenchers located in one of the adjacent phases. By this approach, we can measure the ET kinetics of adsorbed species located mainly at the interface. We have shown that these interfacial ET reactions involving surface species are not sensitive to the interfacial polarisation. More generally, ET reactions at polarised liquid-liquid interfaces will be discussed to place the present results in perspective.
In the second part of the talk, the concept of photo-ionic cells will be presented. Here, the photo-products of a photo-ET reactions occurring in the interfacial region are separated between the two adjacent immiscible phases, thereby resulting in energy storage. This electrochemical energy can then be recovered in a classical parallel plate flow cell. We shall discuss the pros and cons of this method of production of solar fuels.
Benchtop, High-Resolution XAFS and Xes Spectrometers As Tools for Electrochemical Research
Authors: Jahrman Evan , Holden William , Seidler Gerald T. , Fister Timothy T 
Published: February 2020

Advanced x-ray spectroscopies allow the direct and element-specific interrogation of local electronic structure, yet their scientific impact is necessarily constrained by access limitations. This is particularly evident for x-ray absorption fine structure (XAFS) and x-ray emission spectroscopy (XES) techniques. Here, the technical capability afforded by a synchrotron x-ray facility allows researchers to answer basic or applied research questions and push the forefront of science. These national-lab scale sources often provide the only means to perform these techniques, consequently slowing progress on critical projects, and also largely excluding routine analytical characterization.
Over the last four years, our group at the University of Washington has been developing several new families of lab-based instruments to expand the accessibility of advanced x-ray spectroscopies. [1-5] It is now possible to identify the electroactive element in a material and assess its oxidation state, spin state, and coordination chemistry – all with benchtop XAFS and XES. The feasibility of these studies is established by comparing performance of our benchtop instruments with various synchrotrons in the context of several electrochemical systems.
From the standpoint of materials inquiry, we will present a variety of measurements of lithium ion batteries, valence-to-core XES results from a series of oxides, and preliminary efforts toward solution-phase measurements will be presented. The latter will be done with an eye toward future electrolyte analyses.

William M. Holden, et al. “A Compact Dispersive Refocusing Rowland Circle X-ray Emission Spectrometer for Laboratory, Synchrotron and XFEL Applications”, Rev. Sci. Instrum 88, 073904 (2017). [DOI: 10.1063/1.4994739]

T. Seidler, et al., “A Laboratory-based Hard X-ray Monochromator for High-Resolution X-ray Emission Spectroscopy and X-ray Absorption Near Edge Structure Measurements,” Review of Scientific Instruments 85, 113906 (2014). [DOI: 10.1063/1.4901599]

T. Seidler, et al., “A Modern Laboratory XAFS Cookbook,” Journal of Physics: Conference Series 712, 012015 (2016). [ http://iopscience.iop.org/article/10.1088/1742-6596/712/1/012015]

R. Mortensen, et al., “Benchtop Nonresonant X-ray Emission Spectroscopy: Coming Soon to Laboratories and Beamlines Near You,” Journal of Physics: Conference Series 712, 012036. (2016) [http://iopscience.iop.org/article/10.1088/1742-6596/712/1/012036]

G.T. Seidler, “The Case for Analytical XAFS”, https://www.linkedin.com/pulse/case-benchtop-analytical-xafs-gerald-seidler
(Invite) Non-Noble Metal Cored Pt-Skin Catalyst and Its Highly Enhanced Stability in Oxygen Reduction Reaction By Controlling the Nitriding Level for the Core
Authors: Lee Eunjik , Kim Kyung-Hee , Yim Sung-Dae , Park Seok-Hee , Park Gu-Gon 
Published: February 2020

Cost reduction is a key barrier for the commercialization of fuel cells, and the adaption of Core-shell type electrocatalysts is expected to play a major role. Core-shell electrocatalysts have shown remarkable results in terms of activity as well as durability. Electrocatalysts using Pd as a core material has been representative model. It is also announced that durability as well as activity is improved through the use of alloyed or doped Pd cores. In recent years, however, there is a request for a Pt-skin type electrocatalyst which does not use expensive Noble metals. Low-cost transition metals are considered candidates for core materials, but durability is still a challenging issue.
In this study, we introduced Co as a core material and tried to improve the durability through nitriding treatment. The durability of the electrocatalyst was clearly influenced by controlling the nitriding level of Co. CoN@Pt/C was prepared by sonochemical reaction followed by nitriding treatment. Nitriding levels were controlled through pressure control (1, 40, 80 bar) during the ammonia heat treatment process. We confirmed that the active metal has a particle size of (3 - 4) nm and a Pt-skin structure, and confirmed the improved ORR activity over commercial Pt/C catalysts. Most importantly, we have achieved excellent durability when the nitriding level of Co is controlled high. In the accelerated stress test (AST), the electrocatalyst nitrided at the elevated pressure showed little change in ECSA and ORR. It’s confirmed that through the control of the nitriding level for low-cost transition metals, a highly durable Core-shell electrocatalyst can be successfully fabricated.

Figure 1
(Invited) Instability of Pt-Based Catalysts for Fuel Cell Applications
Authors: Shao-Horn Yang 
Published: February 2020

I am delighted to join this symposium and celebrate not only the scientific accomplishments of R. Adzic and but also his contributions to the mentoring of generations of scientists in the electrochemistry and electrocatalysis community. Without formal training in electrochemistry, learning and making high-quality electrochemical measurements is not straightforward. R. Adzic not only has trained a large number of students and postdocs but also has opened his laboratory to other research groups throughout his career, shaping and mentoring future generations of researchers. My own involvements in electrocatalysis in the past decade would not be possible without individuals like R. Adzic who is committed to mentoring and collaborating with researchers coming from other disciplines.
In this talk, I will discuss the mechanisms of Pt and Pt alloy catalyst instability and activity loss in fuel cells (1-2), limiting the lifetime of fuel cells, and how morphologies of Pt alloy particles can influence activity and stability (3-4).

Chen, S., H.A. Gasteiger, K. Hayakawa, T. Tada, and Y. Shao-Horn, Platinum-Alloy Cathode Catalyst Degradation in Proton Exchange Membrane Fuel Cells: Nanometer-Scale Compositional and Morphological Changes, Journal of the Electrochemical Society, 157, A82–97 January 2010.

Ferreira, P.J., G.J. la O’, Y. Shao-Horn, D. Morgan, R. Makharia, S. Kocha and H. Gasteiger, Instability of Pt/C Electrocatalysts in Proton Exchange Membrane Fuel Cells: A Mechanistic Investigation, Journal of the Electrochemical Society, 152, A2256–A2271 2005.

Chen, S., W.C. Sheng, N. Yabuuchi, P.J. Ferreira, L.F. Allard and Y. Shao-Horn, The Origin of Oxygen Reduction Activity of “Pt3Co” Nanoparticles: Atomically Resolved Chemical Compositions and Structures, Journal of Physical Chemistry C, 113, 1109–1125 2009.

Han, B., C.E. Carlton, A. Kongkanand, R.S. Kukreja, B.R.C. Theobald, L. Gan, R. O'Malley, P. Strasser, F.T. Wagner, and Y. Shao-Horn, Record Activity and Stability of Dealloyed Bimetallic Catalysts for Proton Exchange Membrane Fuel Cells, Energy & Environmental Science, 8, 258-266 2015.
(Invited) Surface Sites Probing and Electrocatalytic Property of Atomic Sub-Monolayer and Multilayer on Tetrahexahedral Nanocrystals
Authors: Tian Na , Lin Yan-Fen , Sun Shi-Gang 
Published: February 2020

Tetrahexahedral nanocrystals (THH NCs) of fcc metals such as Pt, Pd, Rh possess a high catalytic activity due to their open surface structure and high surface energy.1 It has been determined that the THH Pt NCs are enclosed by {hk0} facets that can be decomposed with different subfacets. As an example, the most frequently prepared THH Pt NCs are bounded with {730} facets, which can be decomposed into (310) + 2(210) or 3(100)´(110) + 2(100)´(110) + 2(100)´(110). 1,2 It is obvious that the high catalytic activity of the THH Pt NCs originates from the high density of surface active sites.
In the current study through applying cyclic voltammetry (CV) and in situ FTIR spectroscopy, CO adsorption and oxidation were used as probe reactions to investigate the surface sites on THH Pt NCs, in order to understand their role in practical electrocatalysis. Furthermore, the electrocatalytic property towards small organic fuel molecule oxidation of sub-monolayer of adatoms as Bi, Ru and Au on THH Pt NCs, and multi Pt atomic layer on THH Pd NCs were studied to gain knowledge on surface structure effects of high-index faceted nanocrystals in electrocatalysis.

Acknowledgement: This work was supported by Natural Science Foundation of China (21573183, 21621091).

References:

Tian et al. Science, 2007, 316, 732-735.

Hermann, “Crystallography and Surface Structure, an introduction for surface scientists and nanoscientists”, Wiley-VCH, Berlin 2011, ISBN 978-3-527-41012-5.

S. Chen et al. J. Am. Chem. Soc. 2011, 133, 12930.

X. Liu et al. ACS Catalysis, 2012, 2, 708.

X. Liu et al. PCCP, 2012, 14, 16415.

X. Liu et al. Faraday Discuss. 2014, 176, 409.

F. Lin et al, Chem. Sci., 2017, submitted
Electrochemical CO2 Reduction on Oxide-Derived Cu Surface with Various Oxide Thicknesses
Authors: Liang Zhixiu , Fu Jie , Vukmirovic Miomir B , Adzic Radoslav R. 
Published: February 2020

A steadily raising amount of carbon dioxide (CO2) released in atmosphere due to increased consumption of fossil-fuel causes harmful climate change. Additionally, limited reserves of fossil-fuel put a pressure on their future availability thus setting a stage for increased interest in utilizing renewable energy. Electrochemical reduction of CO2 (CO2RR) is a promising way to reduce amount of CO2 as well as generate ‘carbon neutral fuels’ [1]. Among the various CO2RR products, ethylene (C2H4) and ethanol (C2H5OH) are of higher energy density and commercially are more valuable than carbon monoxide (CO) and methane (CH4). Oxide-derived Cu surface is a good candidate for electrochemical CO2 reduction to C2H4 and C2H5OH due to its high activity as well as selectivity [2].
Here we report a systematic study of CO2RR on oxide-derived Cu surface with various oxide thicknesses. The oxide-derived Cu surfaces were prepared via thermal annealing at different temperatures and electrochemical Cu2O plating on Cu foil. The distribution of the CO2RR products, such as CO, CH4, C2H4 and C2H5OH, as well as the rate of hydrogen evolution reaction are highly dependent on the morphology and thickness of the oxide layer. Thus, we can fine tune the performance of the catalyst via deliberate engineering of the oxide-derived Cu surface, Fig. 1. More detailed discussion on the CO2RR performance of these catalysts will be presented at the meeting.
Acknowledgements
This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.
References

Sheng, S. Kattel, S. Yao, B. Yan, Z. Liang, C. J. Hawxhurst, Q. Wu, J.G. Chen, Energy Environ. Sci., 10, 1180 (2017).

W. Li, M.W. Kanan, J. Am. Chem. Soc., 17, 134 (2012).

Figure 1