bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invited: Electrochemical Hydrogen Compression
Authors: Bouwman Peter Jaime , Konink Jonne , Semerel Daniel , Raymakers Leonard , Koeman Menno , Kout Wiebrand , Dalhuijsen Wouter , Milacic Evan , Mulder Martijn J.J. 
Published: February 2020

The company HyET pioneers Electrochemical Hydrogen Compression (EHC) with strong focus on advancing our rate capability and energy efficiency for compression and simultaneous purification. Additional advantages over mechanical pumping are: isothermal compression vs. adiabatic, no moving parts, instantaneous, variable pump rate, included metering, and bi-directional control (de-/compression).
Previously, HyET demonstrated a compression record showing pressures as high as 100MPa are feasible in one single stage using EHC. Simple scalability of the ‘active’ membrane area enabled us to produce stacks with a pumping capacity around 2 kg per day. Stand-alone systems are designed in ongoing JTI funded programs containing multiple parallel stacks and delivering up to 100 kg per day upon request.
Only hydrogen gas is transported through the solid, proton-conducting membrane through conversion at the catalysed membrane surface according to the following reaction equation: H2 = 2 H+ + 2 e-

Other gases that may be present in the mixture stay behind because these cannot follow this pathway.
Proprietary membranes have been developed at HyET to minimise passive permeation of all gases. The primary reason is the reduction of hydrogen back-diffusion, which goes at the expense of the energy efficiency. Secondary, our bespoke membranes automatically show better selectivity towards hydrogen and deliver enhanced purification ability, especially in combination with positive pressure differential.
This presentation will provide insight in EHC working principles, current abilities and potential solutions made available for building a viable hydrogen infrastructure, enabling market application such as:

Automotive (Home) refuelling

Distributed energy storage from sustainable supply

Harvesting from impure hydrogen gas sources

Hydrogen injection and selective extraction from natural gas pipelines
Can CO-Tolerant Anodes be Economically Viable for PEMFC Applications with Reformates?
Authors: Wang Jia X. , He Ping , Zhang Yu , Ye Siyu 
Published: February 2020

Recent advances in removing carbon monoxide (CO) from about 1% to ~10 ppm level via preferential oxidation (PROX) of CO in hydrogen feeds[1] renewed the interest in developing CO-tolerant catalysts for using inexpensive reformates as the fuel other than pure hydrogen. The savings would be considerable since the 2015 price target for hydrogen produced by reforming natural gas is $2 per kg H2, viz., ~40% cheaper than pure hydrogen generated by water electrolysis at $3.5 per kg H2
[2].
RuPt alloy and Ru-Pt core-shell nanocatalysts have been studied as CO-tolerant anode catalysts for PEM fuel cells. However, dissolution of Ru occurs at occasional high potentials experienced at the anode, causing performance decay. To address this issue, we developed a surfactant-free and scalable synthesis method to produce ordered Ru(core)-Pt(shell) nanoparticles with tunable Pt shell thickness of 1 to 3 atomic layers. Commonly found disordering in Ru cores was attributed to defect-induced partial alloying, and was eliminated by annealing Ru cores before coating Pt shells. The single crystalline particles with a sharp Ru-Pt boundary and ordered transition from Ru’s hexagonal close-packed lattice to Pt’s face-centered cubic structure were confirmed by atomically resolved scanning transmission electron microscopy images coupled with density functional theory calculations[3].
We shall mainly show that a complete Pt bilayer shell protects Ru from dissolution during potential cycles up to 0.95 V while exhibiting enhanced CO-tolerance. The results demonstrate a promising anode with less than 0.1 mg cm-2 total metal loadings for operating PEM fuel cells with reformates. In order to find optimal Pt shell thickness and metal to carbon weight ratio, we developed an electrochemical testing method using standalone, gas-diffusion electrodes for evaluating the performance without and with CO in hydrogen. The findings will be discussed in comparison with the results of membrane electrode assembly tests under realistic conditions, shedding light on causes of deactivation effects and ways to alleviate them.

Acknowledgements

The work at Brookhaven National Laboratory was supported by U.S. Department of Energy under contract DE-AC02-98CH10886 and Power Bridge NY.

References

[1] K. Liu, A. Wang, T. Zhang, ACS Catalysis
2012, 2, 1165-1178.
[2] Satyapal, S. http://www.hydrogen.energy.gov/pdfs/htac_apr13_1_satyapal.pdf, Fuel cell technologies update. page 17 (2013).
[3] Y.-C. Hsieh, Y. Zhang, D. Su, V. Volkov, R. Si, L. Wu, Y. Zhu, W. An, P. Liu, P. He, S. Ye, R. R. Adzic, J. X. Wang, Nat Commun
2013, 4, 2466.
The Effect of Cyclic Hygrothermal Loading on the Mechanical Fatigue Durability of PEM Fuel Cells
Authors: M.H. Khorasany Ramin , Singh Yadvinder , Alavijeh Alireza Sadeghi , Kjeang Erik , Wang Gary , Rajapakse Nimal 
Published: February 2020

The membrane electrode assembly (MEA) in polymer electrolyte membrane (PEM) fuel cells undergoes hygrothermal cyclic loading during normal operating conditions. These cyclic loadings create in plane and through plane cyclic stresses being distributed in the membrane. To understand the mechanical fatigue behavior, samples in dogbone shapes (Figure 1) are prepared and placed under the application of cyclic mechanical loadings in controlled ambient conditions [1]. Both pure PFSA membrane and catalyst coated membrane samples are used in the experiments. The tests are conducted ex-situ and the environmental conditions selected in this study cover the temperature and relative humidity levels from those of room conditions to fuel cell conditions. The experimental results are used to benchmark the effect of environmental and loading conditions on the fatigue lifetime of the membrane. Our previous studies [2,3] show that the catalyst layers play a significant role in the mechanical behavior of catalyst coated membranes. Hence, in this study the effect of catalyst layers on the mechanical durability and final elongation of the membrane before the mechanical failure is also investigated.
A strain based fatigue model is then used to develop a finite element numerical scheme for simulating the membrane fatigue lifetime under hygrothermal mechanical loadings. Using the experimental results, the accuracy of the finite element simulations results are verified (Figure 1). The effects of temperature and relative humidity swings on the mechanical longevity of the pure membrane are explored. It is seen that hydration swings have a more profound effect on the fatigue lifetime of the membrane than the temperature swings. Then, using the ex-situ results for the catalyst coated membrane, the impact of the catalyst layers on the membrane/CCM fatigue lifetime is investigated. The finite element model is then used to study the in-situ mechanical stability of pure membranes and catalyst coated membranes under hygrothermal cyclic conditions.

Acknowledgements:

This research was supported by Ballard Power Systems and the Natural Sciences and Engineering Research Council of Canada through an Automotive Partnership Canada (APC) grant.

References

[1] R.M.H. Khorasany, A.S. Alavijeh, E. Kjeang, G.G. Wang, R.K.N.D. Rajapakse, J. Power Sources (2014) under review.
[2] M.A. Goulet, R.M.H. Khorasany, C. De Torres, M. Lauritzen, E. Kjeang, G.G. Wang, N. Rajapakse, J. Power Sources 234 (2013) 38-47.
[3] R.M.H. Khorasany, M.-A. Goulet, A.S. Alavijeh, E. Kjeang, G.G. Wang, R.K.N.D. Rajapakse, J. Power Sources 252 (2014) 176-188.
Figure 1: (a) Dogbone sample used in simulations (with dimensions given in mm), membrane fatigue lifetime at room conditions (23oC, 50% RH) under cyclic mechanical loadings with a maximum force of (b) 1.16 N and (c) 0.95
A Combined Microstructure Characterization of Moisture Permeation Barriers Layers by Means of Electrochemical Impedance Spectroscopy and Ellipsometric Porosimetry
Authors: Perrotta Alberto , Michels Jasper J , García Santiago J , Creatore Mariadriana 
Published: February 2020

In engineering and manufacturing organic electronic devices, encapsulation layers are mandatory due to the sensitivity of active layers and low work function cathodes to moisture. The quality of the barrier is generally validated by means of water vapor transmission rate (WVTR, gm-2day-1) measurements as well as in terms of conformal control on the density of local defects (e.g. pinholes) that act as pathways for the water molecules. Furthermore, it has been demonstrated that the water permeation through the barrier nanoporosity (i.e. the intrinsic barrier), responsible for the homogeneous water permeation through the bulk of the barrier, can be 15-20 times higher than through large defects [1]. While several methods allow the identification of pinholes/defects, novel techniques able to characterize the barrier microstructure in the broad range of nano- and meso-porosity are sought. In this work, electrochemical impedance spectroscopy (EIS) and ellipsometric porosimetry (EP) have been adopted to study the residual (open) porosity and water permeation in PE-CVD and (PE-) ALD single inorganic barrier layers and the results have been correlated to the intrinsic barrier performances as well as to their opto-chemical properties. Trivinyltrimethyl cyclotrisiloxane (dV3D3 = 1 nm) and water (dH2O = 0.3 nm) have been adopted as adsorptives in EP and the barrier microstructure has been studied. The pore size range of 0.3–1 nm and its relative content have been found to control the intrinsic WVTR transition towards the 10-4-10-6 gm-2day-1 regime, highlighting the role of residual nanoporosity in controlling the intrinsic barrier properties [ref]. Furthermore, EIS has been employed for the first time to study the water uptake (φ, the volume fraction of water) and diffusivity coefficient (D) of different moisture barrier layers. The layer capacitance has been determined by modelling the impedance data with the proper equivalent circuit and the change of the capacitance upon water permeation has been followed. The Brasher-Kingsbury equation has been successfully applied and φ and D values in the range of 0.8-4% and 10-13-10-15 cm2sec-1 have been found, respectively. In addition, the diffusion of cations having different hydrated shell sizes, i.e. Na+, Li+, K+ and Cs+, through the barriers has been studied. Changes in the resistance of the layer have been attributed to the formation of conductive pathways due to the ion diffusion. With this method, the relative pore size distribution in the range 0.3-1 nm has been characterized in detail.
[1] J. Affinito, D. Hilliard, in: 47th Annual Technical Conference Proceedings (2004) 563.
[2] A. Perrotta, E.R.J. van Beekum, G. Aresta, A. Jagia, W. Keuning, M.C.M. van de Sanden, W.M.M. Kessels, M. Creatore, Microporous and Mesoporous Materials, 188 (2014), 163-171.
Understanding the Meat Color Attributes by Direct Electrochemistry of Myoglobin Films on Electrodes
Authors: Krishnan Sadagopan , Nerimetla Rajasekhara , Walgama Charuksha , Ramanathan Ranjith 
Published: February 2020

Protein film electrochemistry (PFE) is a unique method with high simplicity to obtain mechanistic information about complex biological electron transfer and catalytic processes. The emerging applications of PFE are in the development of selective biosensors, biofuel production, renewable energy processes, green biocatalytic systems, and biomedical tools.[i],[ii],[iii] Along this line, we are exploring the novel utilization of heme-protein electrochemistry to understand the meat color qualities. Myoglobin (Mb) is a muscle protein predominantly responsible for meat color. Mb can exist in three different forms namely deoxy-, oxy-, and metmyoglobin. The extent of oxymyoglobin (Mb-FeII-O2) state mainly influences the characteristic red color of meat. On the other hand, the oxidation of oxy- or deoxymyoglobin leads to discoloration of meat or metmyoglobin (Mb-FeIII) accumulation.
Our objective was to investigate the kinetics of metmyoglobin reduction and oxymyoglobin formation using myoglobin model and examine its relevance to meat color properties. For our initial electrochemical analysis, we have chosen three meat related pH conditions such as pH 7.4 (physiological muscle), pH 6.4 (stress-out animal muscle), and pH 5.6 (typical postmortem muscle) and investigated the rates of Mb-FeIII reduction and Mb-FeII-O2 formation using Mb-films adsorbed on graphite electrodes. We observed that under the physiological muscle pH condition, the rates of Mb-FeIII reduction and the subsequent formation of Mb-FeII-O2 were highly favored in comparison to the low acidic pH conditions. Our electrochemical results correlated well with the prior biochemical and redox-titration studies that reported the faster discoloration of meat with lowering pH conditions.[iv],[v] Our investigation suggests that myoglobin-PFE is simple, inexpensive, rapid, and powerful in probing atomic level redox-properties, and thus a valuable tool to predict meat color.

Acknowledgements. This work was supported by the Oklahoma State University.

[i]. (a) M. Meredith and S.D. Minteer, Annu. Rev. Anal. Chem., 2012, 5, 157-179; (b) S. Xu and S.D. Minteer, ACS Catalysis, 2013, 3, 1756-1763.
[ii]. L. Halamkova, J. Halamek, V. Bocharova, A. Szczupak, L. Alfonta and E. Katz, J
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, 5040.
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., 2012, 3, 1015-1023; (b) S. Krishnan and J. F. Rusling, Thin Iron Heme Enzyme Films on Electrodes and Nanoparticles for Biocatalysis, Chapter 5, p.125, in New and Future Developments in Catalysis, S. Suib (Ed.), Elsevier Publishers, 2013; (c) C. Walgama and S. Krishnan,J. Electrochem. Soc., 2014, 161, H1-H6; (d) S. Krishnan and C. Walgama, Anal. Chem.,
2013, 85, 11420−11426.
[iv]. A. L. Alderton, C. Faustman, D. C. Liebler, D. W. Hill, Biochemistry
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[v]. R. Ramanathan, R. A. Mancini, G. A. Dady, C. B. Van Buiten, Meat Science
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The Influence of the Interaction between Silicon and Hydroxyl Radicals before the Copper Electrodeposition. Activity Changes of the Silicon Surface
Authors: Muñoz Eduardo Carlo , Navarrete Emilio Alonso , Heyser Cristopher Alejandro , Henríquez Rodrigo Gonzalo , Schrebler Ricardo Silvio , Córdova Ricardo Alejandro 
Published: February 2020

Several studies have emerged in an attempt to explain the aging process which occurs in the human body, where free radicals (FR) are species involved in these alterations. Considering this subject, there is a great interest in being able to detect, quantify and control the amount of FR that human body produces at certain periods, and especially the hydroxyl radical (OH) [[i],[ii]].
In this study we examined the changes in the surface activity of n-Si after its exposition to a solution containing hydroxyl radicals. Changes in the surface activity caused by the interaction between silicon and OH radicals were characterized by analyzing the nucleation and growth mechanism (NGM) of copper on silicon electrodes. For this aim, we studied the copper deposition on: i) n-Si without exposure to hydroxyl radicals and ii) n-Si exposes at different periods of time to hydroxyl radical. It was observed a change in the copper NGM on n-Si, from 3D progressive nucleation diffusion-controlled growth (PN3DDIFF), for the system without exposure to the OH radical, toward 3D instantaneous nucleation diffusion-controlled growth (IN3DDIFF), when the semiconductor substrate was exposed to the OH radicals. In both cases analysis by the Atomic Force Microscopy (AFM) technique was performed confirming these mechanisms.

[[i]] Tomasz Rapecki, Anna M. Nowicka, Mikolaj Donten, Fritz Scholz, Zbigniew Stojek, Electrochem. Commun. 12, (2010), 1531-1534.

[[ii]] Anna Maria Nowicka, Ulrich Hasse, Mikolaj Donten, Michael Hermes, Zbigniew Jan Stojek, Fritz Scholz, J Solid State Electrochem., 15, (2011), 2141–2147.
Monolayer Catalyst Design Using Slrr of UPD Monolayers – Fundamental Aspects and Interplay of UPD, Reaction Kinetics, and Nucleation Kinetics
Authors: Brankovic Stanko 
Published: February 2020

The deposition protocol based on surface limited Redox replacement reaction (SLRR) of UPD monolayers [[i]] has gained a lot of attention in recent years. It has been extensively used for preparation of highly active catalysts [[ii],[iii],[iv],[v],[vi],[vii]], and for growth of homo/heteroepitaxial 2D films with arbitrary thickness [[viii],[ix]]. The concept behind this deposition protocol has potential for a wide range of applications, yet very little is known about the governing phenomena determining morphology of deposited catalyst monolayers.
In this talk we will review fundamental relations controlling the catalyst monolayer nucleation as a prelude for its morphology design. The analytical model describing the nucleation density as a function on reaction stoichiometry, rate constant, reaction order, and fundamental parameters describing surface transport will be presented and discussed with reflection to experimental data. We will show the practical relevance of SLRR reaction kinetics on deposition flux and nucleation kinetics of metal/catalyst monolayers. The different approaches for manipulation of the reaction kinetics and thermodynamics will be discussed within the frame of experimental design/protocols to control the morphology of deposited catalyst monolayers. The emphasis will be made on some convenient and yet allowed approximation relevant to the real systems.
In the second part of the talk the spectroscopic data will be presented emphasizing that catalyst morphology i.e. nanocluster size is an important design parameter directly affecting the monolayer catalyst performance. Examples of Pt/Pd(hkl) and Pt/Au(hkl) will be discussed with in the light of the Pt monolayer morphology.
In the last part of the talk we will show the examples of Pb UPD on Pt and Ru modified Au(111) as a prelude to design of the novel 2D catalyst monolayers and nanoclusters configurations.

The authors acknowledge the support from NSF Chemistry division under the contract # 0955922.

[1] SRBrankovic@uh.edu

References:

[i]) S. R. Brankovic, J. X. Wang and R.R. Adzic, Surface Science, 474, L173 (2001).
[ii]) V. M. Brussel, G. Kokkinidis, A. Hubin, C. Buess-Herman, Electrochim. Acta
48, 3909 (2003).
[iii]) J. L. Znahg, M.B. Vukmirovic, Y. Xu, M. Marvikakis, R. R. Adzic, Angewandte Chemie-International Edition,
44, 2132 (2005).
[iv]) J. L. Znahg, M.B. Vukmirovic, K. Sasaki, A. U. Nilekar, M. Marvikakis, R. R. Adzic, J. Am. Chem. Soc.,
127, 12480 (2005).
[v]) A. Kongkanand, and S. Kuwabata, J. Phys. Chem. B, 109, 2319 (2005).
[vi]) Y. D. Jin, Y. Shen, and S. J. Dong, J. Phys. Chem.
B, 108, 8142, (2004).
[vii]) K. Sasaki, Y. Mo, J. X. Wang, M. Balasubramanian, F. Uribe, J. McBreen, R.R. Adzic, Electrochim. Acta, 48, 3841, (2003).
[viii]) R. Vasilic, L.T. Viyannalage and N. Dimitrov J. Electrochem. Soc.,
153, C648, (2006).
[ix]) Y.G. Kim , J.Y. Kim, D. Vairavapandian, J.L. Stickney, J. Phys. Chem.
B
110, 17998 (2006)
O2 Reduction at Se Modified Surfaces: Characterization by SPM and DEMS
Authors: Baltruschat Helmut , Iqbal Shahid , Bondü Christoph 
Published: February 2020

Metal chalcogenides have been extensively studied as catalysts for oxygen reduction reactions, due to their tolerance for small organic molecules especially in relation to fuel cell applications. We have recently reported that also adsorption of Se on polycristalline Ru leads to an increased activity as compared to Ru.[1]. A theoretical study also showed that intermediate surface contents of Ru or Rh by Se or S lead to an increased activity.[2] However, fundamental studies on well-defined rhodium (Rh) single-crystal surfaces modified with chalcogenides (Se) are very rare.
Here, irreversible adsorption of Se on Rh(111) was examined by voltammetric technique. Surface structure characterization of Se modified Rh(111) substrate was achieved using cyclic voltammetry and in situ STM and AFM. STM images also show a roughening starting at step edges for Se adsorption at certain potentials, similar to the roughening transition observed on Au(111) surface for S and Se adsorption [3][4] or As on Pt(111)[5], suggesting the formation of an. Se–Rh intermetallic compound. Results on the effect on oxygen reduction activity will be presented.
It was observed that chalcogenides usually stripped off under fuel cell operating conditions [6] and also electrochemical hydrogen selenide formation at lower potentials [7].Here, we used differential electrochemical mass spectrometery (DEMS) for an additional quantitative characterisation of Se adlayers via reductive desorption on model fcc metal surfaces like [Rh(111), Pt(111) and Au(111)]

References

[1] N. Bogolowski, T. Nagel, B. Lanova, S. Ernst, H. Baltruschat, K. Nagabhushana and H. Boennemann, J. Appl. Electrochem., 37 (2007) 1485
[2] Tritsaris, G. A.; Nørskov, J. K.; Rossmeisl, J.; Electrochim. Acta 56 (2011) 9783.
[3] C. Wei, N. Myung, K. Rajeshwar, J. Electroanal. Chem. 375 (1994) 109.
[4] T.A. Sorenson, K. Varazo, D.W. Suggs and J.L. Stickney, Surf. Sci., 470 (2001) 197.
[5] X.Y. Xiao and H. Baltruschat, Langmuir, 19 (2003) 7436.
[6] D. C. Papageorgopoulos, F. Liu and O. Conrad, Electrochimica Acta 52 (2007) 4982.
[7] M. O. Solaliendres, A. Manzoli, G. R. Salazar-Banda, K. I. B. Eguiluz, S. T. Tanimoto and S. A. S. Machado, J. Solid State Electrochem. 12 (2008) 679.