bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self-Supported PdSnx Catalysts for the Electrooxidation of Alcohols
Authors: Coutanceau Christophe , Zalineeva Anna , Padilla Monica , Serov Alexey , Baranton Stève , Atanassov Plamen 
Published: February 2020

Palladium-based nanocatalysts possess high activity and stability towards alcohol oxidation reactions in alkaline media, and can then be considered as possible economical substitutes of Pt for alcohol oxidation. There is indeed an increasing number of published works devoted to the development of Pt-free anode catalysts for direct alcohol fuel cells1-3.
In addition, Sn is known to an excellent co-catalyst for the electrooxidation of alcohol, particularly ethanol, in acidic as well as in alkaline media.4,5

In the present communication, we present the synthesis by the sacrificial support method (SSM), which was developed by the research group of Prof. Atanassov6,7
, of a series of self-supported PdSnx catalysts with different atomic ratios and their physicochemical characterization by different methods, such as BET, SEM, TEM, EDX, XPS, and electrochemical method.
The influence of the Pd:Sn atomic ratio on the electrocatalytic behavior towards alcohol oxidation is investigated in alkaline medium, with particular interest to glycerol which is a renewable raw material produced from the biofuel industry. In addition to the promotional effect of tin towards the catalytic activity, the effect on the mechanism of glycerol electrooxidation is also determined using in situ infrared spectroscopy measurements.
At last, the promotional effect of tin is also confirmed for other primary and secondary monoalcohols, and polyols.
1- A. Serov, C. Kwak, Appl. Catal. B: Environmental 90, 313(2009).
2- C. Bianchini and P. K. Shen, Chem. Rev. 109, 4183(2009).
3- M. Simoes, S. Baranton and C. Coutanceau, Appl. Catal. B: Environmental 93, 354 (2010).
4- C. Lamy, S. Rousseau, E. M. Belgsir, C. Coutanceau, J. -M. Léger, Electrochim. Acta 49, 3901 (2004).
5- R. M. Modibedi, T. Masombuka, M. K. Mathe, International Journal of Hydrogen Energy 36, 4664 (2011).
6- A. Serov, U. Martinez, P. Atanassov Electrochem. Comm. 34, 185 (2013).
7- A. Serov, U. Martinez, A. Falase, P. Atanassov Electrochem. Comm. 22, 193 (2012).

Acknowledgment: Anna Zalineeva thanks the Center for Emerging Energy Technologies, Farris Engineering Center (UNM) for assistance and technical support, and the county council of Poitou- Charentes (France) for financial support. UNM portion of this work was funded in part by DOE-BES EPSCoR Implementation Award: “Materials for Energy Conversion”.
The Application of Ultrasound to the Coating of Platinum Catalyst on Membrane for Proton Exchange Membrane Fuel Cell
Authors: Kim Youngkwang , Kim Kanghoon , Choi Insoo , Kim Jae Jeong , Kwon Oh Joong 
Published: February 2020

MEA (Membrane Electrode Assembly) consisting of the electrodes coated with a catalyst and the membrane is the most important in fuel cell. In fabricating MEA, there are two ways to coat catalyst depending on a coating substrate, i.e. CCM (Catalyst Coated Membrane, coating on membrane), and CCS (Catalyst Coated Substrate, coating on carbon paper). Generally, CCM is known as a better way than CCS, and spray coating has been widely used for CCM method. In this study, CCM method was also adopted to make MEA, however, catalyst was coated sonochemically to introduce a new catalyst coating method in making MEA.
The most convincing and famous mechanism known for a sonochemical metal ion reduction is a reduction of metal precursor by radicals generated by hot spot during ultrasound irradiation1. Thus we introduced ultrasound irradiation for synthesizing and coating of platinum on membrane simultaneously. In applying ultrasound irradiation, we changed experimental conditions such as time of radiation and the intensity of radiation. The amount of platinum loaded on membrane was proportion to the time and the power of ultrasound irradiation as shown in Fig. 1. The solution used for platinum electrode formation includes not only platinum precursor but also a reducing agent and a surfactant to help precursor reduction. After Pt catalyst coating, remaining impurities like a reducing agent and a surfactant were removed by using stirring in pure water.
In order to check whether platinum was successfully loaded on membrane, FE-SEM (Field Emission Scanning Electron Microscope) and EDS (Energy Dispersive x-ray Spectroscopy) analyses were carried out as shown in Fig. 2, and it proved the effectiveness of ultrasound irradiation in making platinum electrode on membrane. Furthermore, we looked into the electrochemical characteristics of the MEA using CV (Cyclic Voltammertry) and EIS (Electrochemical Impedance Spectroscopy), and then the result was compared with that of a conventional MEA. MEAs, both new and conventional, were made into single cells for a performance test and a comparison. In making a single cell with the MEA made by ultrasound irradiation, ionomer effect was thoroughly studied to take advantage of thin thickness of platinum catalyst layer. It is known that the mass transfer through thin film catalyst layer is fast without ionomer2.
In thus presentation, all the results investigated in the study will be presented with in-depth discussion.
References:
1. J. H. Bang and K. S. Suslick, Adv. Mater., 22, 1039 (2010).
2. A. K. Schmoeckel, G. D. Vernstrom, R. Atanasoski, and M. K. Debe, J. Power Sources, 161, 1002 (2006).
Methanol and Ethanol Electro-Oxidation on the Platinum-Cobalt Catalyst Deposited on the Titanium Surface
Authors: Stankevičienė Ina , Cinciene Zana , Balciunaite Aldona , Zabielaite Ausrine , Vaiciuniene Jurate , Verbickas Rolandas , Selskis Algirdas , Tamasauskaite-Tamasiunaite Loreta , Norkus Eugenijus 
Published: February 2020

This work is focused on the preparation of platinum-cobalt catalysts deposited on the titanium surface (denoted as Pt(Co)/Ti) using simple chemical methods as electrocatalyts towards the electro-oxidation of methanol and ethanol in an alkaline medium. The Pt-Co catalysts were deposited on the titanium surface by a two-step process which involves electroless cobalt deposition followed by a spontaneous Pt displacement from platinum-containing solution.
The morphology, structure and composition of the prepared catalysts were examined by Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Analysis and Inductively Coupled Plasma Optical Emission Spectroscopy. The electrochemical behavior of the prepared catalysts towards the oxidation of methanol and ethanol was investigated by means of cyclic voltammetry, chronoamperometry and chronopotentiometry.
The Pt(Co)/Ti catalysts with low Pt loading demonstrated their significantly higher electrocatalytic activity towards methanol and ethanol oxidation as compared to that of bare Pt and Co/Ti electrodes and seem to be a promising anode materials for direct methanol and ethanol fuel cells.
Application of Carbon Coated Stainless Steel for Bipolar Plate in Proton Exchange Membrane Fuel Cell
Authors: Hsieh HoYen , Wang Wen-Lin , Lan ChaoHo 
Published: February 2020

Stainless steel bipolar plates for the polymer electrolyte membrane (PEM) fuel cell offer many advantages over conventional machined graphite. Austenitic stainless steel 316L is a traditional candidate for metal bipolar plates.During a long operation time, metal oxide formation leads to contact resistance, and metal dissolution can cause contamination of the membrane electrode assembly (MEA). A pure Carbon was coated on the surface of Stainless steel and provided a good anticorrosion layer. The carbon film has a low area specific resistance compared to the composite coating because it has a high surface conductivity. In addition, The ICR between the carbon-coated SS316 and the carbon paper is 225–1247 mΩ-cm2 under compaction forces between 20 and 280 N cm−2. The carbon-coated SS316L shows good corrosion resistance in the simulated PEMFC environment. After testing the single cell for 4000hr, the power density was decay less than 1%. Therefore, the carbon-coated SS316L has an excellent durability property.
Key words : fuel cell, carbon and bipolar plate
Study on Condition of Low-Cost Carbon-Based Surface Treatment for Application of Metallic Bipolar Plates in PEMFC
Authors: Kim Myong-Hwan , Goo Youngmo , Yoo Seung-Eul 
Published: February 2020

Metallic bipolar plates coated with low-cost carbon-based surface treatment were developed for polymer electrolyte membrane fuel cells(PEMFC) and were evaluated by properties(corrosion, contact resistance) and performance(I-V curve). The carbon-based coating by dry surface treatment exhibited a good mechanical strength and corrosion resistance. But these could not be applied as bipolar plates because of a high electrical resistance by non-conductive structure(sp3↑, sp2↓). In this study, we developed the metallic bipolar plates with conductive structure((sp3↓, sp2↑) by change of coating temperature and thickness.
The coating thickness(A type, B type) and temperature(A-1~4, B-1~4) were used as parameters for conductive bipolar plates. The B type sample was more thicker than A type and A-4 sample was treated with heat more higher than A-1. These samples were evaluated by properties and performance of unit cell.
The surface treatment temperature of A-3 sample exhibited low contact resistance and corrosion current density. This trend showed in B type sample. Therefore, the condition of A-3 or B-3 revealed the optimum temperature in this experiment. However, the increase of coating thickness was for nothing in properties. The fuel cell assembled from metallic bipolar plates coated with carbon-based surface treatment exhibited the same performance as compared with graphite.
Invited: Study of Fundamental Aspects of Ionomer Structure in Different States
Authors: Ohira Akihiro , Kuroda Seiichi , Yamaguchi Makoto , Oshima Tatsuya , Matsuura Toyoaki , Ogu Kenichi , Rikukawa Masahiro 
Published: February 2020

In PEFC system, the ionomer is used as a binder and an electrolyte membrane. The characteristics of low gas permeability and high proton conductivity are required for the electrolyte membrane, while, if the ionomer is used as a binder, conductivity should be high as well as electrolyte membrane, but in this case, high gas permeability should be better which is opposed to the case of membrane characteristic. Nafion® is used for binder and electrolyte membrane, but there still has been unclear factor about structural difference in both binder and membrane states, especially we do not know about the effect of structure and physical properties of ionomer in a catalyst layer on cell performance.
In this study, we prepared model ionomer materials and electrodes, and conducted the structural analysis in order to understand the effect on the cell performance systematically.
Perfluorinated sulfonic acid ionomer Nafion® and di-block copoly(p-phenylene) ionomer having sequentially controlled hydrophilic and hydrophobic parts were targeted as the model ionomer1 (Scheme 1). As the model electrode, we also used Pt-dispersed carbon electrodes in which several nanometers Pt particles dispersed2. We performed microscopic observation and scattering analysis in order to understand the structures in solution and thin film solid states.
Here Nafion® thin film was prepared on platinum nano-particle dispersed carbone electrode as a model for the ionomer film within a catalyst layer. We found that aggregated structure of ionomer changed with carbon surface area, the size of aggregated structure became large, and proton conductive domain also enlarged with the increase in carbon surface area. These results imply that the morphology and the property of ionomer covering catalyst support could be dominated by balance of interaction between carbon and platinum. In the case of hydrocarbon ionomer, it has been found that di-block copolymer forms higher order structure over a range of several hundred nm by means of AFM observation. Furthermore, the gas permeability of di-block copolymer film was comparable to that of Nafion®. Details will be discussed at presentation.

Acknowledgement

Ministry of Economy, Trade and Industry (METI), Japan and New Energy and Industrial technology Development Organization (NEDO) are acknowledged for granting the work.

References

1. K. Umezawa, T. Oshima, M. Yoshizawa-Fujita, Y. Takeoka, and M. Rikukawa, ACS Macro Lett.
2012, 1, 969−972.
2. T. You, O. Niwa, M. Tomita, and S. Hirono, Anal. Chem.
2003, 75, 2080-2085.
Understanding the Growth of Pt Nanoparticles by Galvanic Displacement on ITO Nanocubes for ORR
Authors: Liu Ying , Zhao Shuai , Mustain William E 
Published: February 2020

Though proton exchange membrane fuel cells (PEMFCs) are at the cusp of widespread commercialization, there are several issues that must be addressed to improve their long-term reliability. One considerable improvement to existing PEMFC systems would be in incorporation of higher stability electrocatalysts, while concomitantly improving activity to reduce loading and cost, at the oxygen reduction cathode.
Recent work in our group has focused on investigating the intrinsic stability of Sn-doped indium oxide [1] as well as its activity and stability in the ORR environment [2]. This work has even included the investigation of the influence of Pt loading on ITO and its effect on the oxygen reduction activity and Pt/ITO stability [3]. One of the more interesting findings for Pt/ITO prepared by galvanic displacement is that low Pt loadings yield a single type of particle with preferential {111} faceting, which gives yields its characteristic high activity. However, at higher loading secondary particles with a completely different structure emerge. One of the most interesting open questions is how these two particle types influence the activity and stability of the Pt/ITO.
In this work, we present a statistical model that utilizes a modified Poisson probability distribution function to understand how the primary and secondary Pt nanoparticles grow during the galvanic displacement. The statistical model is also used to predict the specific and mass activity of the Pt/ITO as a function of Pt loading. The model prediction and experimental results for the specific activity are shown in Figure 1. Excellent agreement was observed between the theoretical prediction and the experimental data. Also, an interesting oscillatory behavior was predicted, which also appears corroborated by the experimental data. The behavior is caused by the counterbalancing of the high activity of the preferentially faceted Pt/ITO nanoparticles and the secondary particles that show and activity similar to Pt supported on carbon. The number of {111} also clearly plays a role [4], which is built into the model.
This talk will focus on the model development, calculation of model parameters, and linking critical elements of the model to the activity and stability of Pt/ITO electrocatalysts for the oxygen reduction reaction.

References.

Y. Liu and W.E. Mustain, “High stability, high activity Pt/ITO oxygen reduction electrocatalysts”, J. Am. Chem. Soc., 135 (2013) 530

Y. Liu and W.E. Mustain, “Stability limitations for Pt/Sn–In2O3 and Pt/In–SnO2 in acidic electrochemical systems”, Electrochimica Acta, 115 (2014) 116-125

Y. Liu and W.E. Mustain, “High Stability, High Activity Pt/ITO Oxygen Reduction Electrocatalysts”. Abstract 86, 223rd Meeting of the Electrochemical Society, San Francisco, CA.

M. Shao, A. Peles and K. Shoemaker, Nano Letters, 11 (2011) 3714.
Invited: Development of Nstf Electrode for PEMFC
Authors: Kongkanand Anusorn , Sinha Puneet , Liu Zhongyi , Thompson Eric , Zhang Jingxin , Kukreja Ratandeep , Moylan Thomas , Clancey Joel W. , Cavanagh Andrew S. , George Steven M. 
Published: February 2020

Ionomer-free ultrathin electrodes, such as the 3M Nanostructured Thin Film (NSTF) electrode, provide a plausible pathway to reduce Pt cost and enhance the electrode durability in low temperature fuel cells. However, the absence of ionomer, the small electrode thickness, and the small Pt area make operating a fuel cell a challenge.
We have developed several materials and system solutions to mitigate these issues1,2 and numeric models3,4 to enhance our understanding of fuel cell performance in NSTF electrodes. We then further investigated the stability of the NSTF electrodes under accelerated tests5 and tests that were designed to simulate real-life automotive operation6. We observed irreversible voltage decay behavior that could not be explained by known electrode degradation mechanisms of carbon corrosion, Pt dissolution, or membrane thinning. Correlation among different events that contribute to the degradation will be discussed. For example, we found that it is important to avoid entering a potential window in which irreversible degradation occurs. Mitigation strategies to maximize the electrode life will be suggested.
Lastly, we will present our recent development in using atomic layer deposition to form a uniform thin layer of Pt on an NSTF support. This method can reduce the Pt loading by a factor of three compared to the current method. Its fuel cell activity will be also discussed.

Acknowledgements

The authors thank Mark K. Debe, Edward M. Fischer, and Andrew Steinbach of 3M for providing NSTF MEAs and for useful discussions. Thanks are also extended to Frank Coms, Wenbin Gu, Yeh-hung Lai for insightful comments; Ted Gacek, Heidi Viterise, Tom Jackson, Matt Dioguardi, Jeanette Owejan, Scott Moose, Travis Downs, and Rob Moses for engineering support.

References

A. Kongkanand, M. Dioguardi, C. Ji and E. L. Thompson, Journal of the Electrochemical Society, 159, F405 (2012).

A. Kongkanand, J. E. Owejan, S. Moose, M. Dioguardi, M. Biradar and R. Makharia, Journal of the Electrochemical Society, 159, F676 (2012).

A. Kongkanand and P. K. Sinha, Journal of the Electrochemical Society, 158, B703 (2011).

P. K. Sinha, W. Gu, A. Kongkanand and E. Thompson, Journal of the Electrochemical Society, 158, B831 (2011).

A. Kongkanand, Z. Liu, I. Dutta and F. T. Wagner, Journal of the Electrochemical Society, 158, B1286 (2011).

A. Kongkanand, J. Zhang, Z. Liu, Y. Lai, P. Sinha, E. Thompson, R. Makharia, submitted to Journal of the Electrochemical Society (2014).
High-Resolution Mapping of the PFSA Polymer Distribution in PEFC Electrode Layers
Authors: Koestner Roland John , Cullen David A , Kukreja Ratandeep , Minko Sergiy , Meyer Harry M , Liu Zhongyi , More Karren L. 
Published: February 2020

Perfluorosulfonic acid (PFSA) ionomer is a key component within the electrode layers of polymer electrolyte fuel cells (PEFCs) since this solid electrolyte provides an efficient proton transport path to the active catalyst sites. Both the average loading on a 100-nm scale as well as the actual film thickness distribution on a 1-nm scale of the PFSA ionomer in the porous layer structure are critical to electrode performance so quantitative measurements of both properties are highly desired.
Scanning transmission electron microscopy (STEM) is one useful tool to map this PFSA distribution in the electrode layer [1]. However, it has long been recognized that fluorinated compounds are sensitive to electron beam radiation damage [2,3]. By maintaining an electron dose below 1x104 e-/nm2 at 100-nm lateral resolution and cooling the specimen below -100ºC, the total fluorine mass loss for Nafion® ionomer is held below 10% a/a whereby the electron beam damage threshold for a typical Pt/C electrode layer is improved by 2-3 orders-of-magnitude at this sample temperature.
Atomic force microscopy (AFM) [4] is a complementary tool suitable to map the Nafion® coverage on a 1-nm length scale on the electrode surface. The adhesion of the AFM tip to Nafion® in air was measured to be very low as the fluorocarbon backbone was preferentially exposed at polymer-air interface.
In this paper, we present ionomer mapping measurements of two common PEFC electrode constructions. Figure 1 shows Pt/C/Nafion® layers at 8 μm dry thickness that are coated from the same electrode ink onto either a decal substrate (CCD) or directly onto the gas diffusion media. The other electrode layer comprises a PtCoMn nanostructured thin film (NSTF) electrode [5] that is overcoated with Nafion® ionomer using a preferred adsorption scheme to a targeted 2.0 nm dry thickness.
Figure 2 shows that a significantly different through-layer ionomer/carbon (I/C w/w) profile is measured by energy-dispersive X-ray spectroscopy (EDS) for the CCD and CCDM electrode layers that can be ascribed to partial permeation of the electrode ink solution into the porous gas diffusion media substrate. In addition, the AFM adhesion measurement in Figure 3 shows a linear increase in ionomer coverage on the NSTF electrode surface to the adsorption limit (at
2 nm dry thickness).
ORNL Research sponsored by (1) the Fuel Cell Technologies Office, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy and (2) the Shared Research Equipment (ShaRE) User Facility, which is sponsored by the Office of Basic Energy Sciences, U.S. Department of Energy.
Characteristics of Paper-Based Lactate-O2 Biofuel Cell and Its Application for Wearable Devise
Authors: Shitanda Isao , Yagi Yuki , Momiyama Misaki , Hoshi Yoshinao , Itagaki Masayuki , Tsujimura Seiya 
Published: February 2020

There has been considerable recent interest in wearable biofuel cells based on printing technologies.1 Screen-printing technique has following merits; drawing precise pattern of um order, a wide variety of inks, high reproducibility, and low cost. Thus, screen-printing has been widely used for fabrication of electrochemical devices such as dye-sensitized solar cells, biosensors and corrosion sensor. 2-5

Recently, we prepared a screen-printed paper-based biofuel cell using porous carbon inks and showed its high output power. 6 In the present study, we newly demonstrated a screen-printed paper-based biofuel cell which consisted of lactose oxidase-modified and billirubin oxidase-modified porous carbon electrode fabricated on the paper substrate. Firstly, the characteristics of the bioanode and biocathode were investigated independently by the three-electrode method; the bioanode or biocathode was connected to a potentiostat. A Ag|AgCl reference electrode and Pt wire counter electrode were placed in the electrolyte solution. Then, electrochemical response of the BFC was examined.
References
1. W. Jia, G. Valdes-Ramirez, A. J. Bandodkar, J. R. Windmiller, J. Wang Angew. Chem. Int. Ed., 52, 7233 (2013).
2. M. Itagaki, Y. Nakano, I. Shitanda, K. Watanabe, Electrochim. Acta , 56, 7975 (2011).
3. I. Shitanda, S. Takamatsu, K. Watanabe, M. Itagaki, Electrochim. Acta, 54, 4933 (2009).
4. I. Shitanda, A. Okumura, M. Itagaki, K. Watanabe, Sens. Actu. B-Chem, 139, 292 (2009).
5. I. Shitanda, T. Yamaguchi, Y. Hoshi, M. Itagaki, Chem. Lett. 42, 1369 (2013).
6. I. Shitanda, S. Kato, Y. Hoshi, M. Itagaki, S. Tsujimura, Chem. Comm. 49, 11110 (2013).