bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Performance Anode Material for Solid Oxide Fuel Cells: Ni Exsolution on a-Site Deficient La0.4Sr0.4Sc0.9Ni0.1O3
Authors: Gao Yang , Ciucci Francesco 
Published: February 2020

Highly efficient and environment-friendly devices for energy transformation are in urgent demand for the sustainable production of power. Solid oxide fuel cells (SOFCs) are among the most efficient systems that can convert chemical energy directly into electricity. Currently, Ni/yttria-stabilized ZrO2 (YSZ) is the state-of-the-art SOFC anode material (or the cathode material of solid oxide electrolysis cells), due to its relatively high mechanical strength, high performance, and low cost. However, the Ni/YSZ anode still has several limitations including Ni agglomeration at high temperature, sulfur poison, and carbon coking. While perovskite-type materials have been used as SOFC anodes to overcome many of these challenges, their catalytic activity is typically poor. Recently, exsolution of catalytic nanoparticles on the surface of perovskites has drawn great research interest because of the potential enhancement in electrochemical activity. Irvine and collaborators have shown that A-site deficient perovskites allow easier and more controllable exsolution, and several materials capable of growing nanoparticles in-situ have been developed. However, the catalytic activity delivered by A-site deficient perovskites with exsolved nanoparticles is still not comparable to that of state-of-the-art SOFC anode materials. There are still many opportunities for materials development and improvement, since most of the recent studies have focused on La0.5Sr0.5TiO3 or NbTiO4
related materials. Perovskites based on other non-easily-reducible metals may be used to deliver even better activity.
In this work, we report a novel Sc-based A-site deficient perovskite La0.4Sr0.4Sc0.9Ni0.1O3-δ (LSSN), synthesized as an anode material for solid oxide fuel cells. LSSN is reduced in hydrogen at 900 oC for 15 hours to form a highly active and stable anode. Spherical Ni nanoparticles (~100 nm in diameter) with well-defined boundaries are exsolved on the surface after reduction. the reduced LSSN (rLSSN) show high electrochemical catalytic activity, with the area specific resistances as low as 0.055 Ω cm2 at 800 °C in humid H2. Our work introduces a new anode material with potential to enhance electrochemical catalytic activity and suggests a new series of A-site deficient perovskites for SOFC anodes.
Developing Low-Intermediate Temperature Fuel Cells for Direct Conversion of Methane to Methanol Fuel
Authors: Torabi Alireza , Barton Joseph , Willman Carl , Ghezel-Ayagh Hossein , Li Na , Poozhikunnath Abhinav , Maric Radenka , Marina Olga A 
Published: February 2020

The direct conversion of methane to liquid fuels and chemicals is highly sought, especially at low-scale to more effectively utilize remote natural gas resources. The objective of this project is development of a durable, low-cost, and high performance Low Temperature Solid Oxide Fuel Cell (LT-SOFC) for direct conversion of methane to methanol and other liquids, characterized by: a) Operating temperature < 500oC, b) Current density of > 300 mA/cm2, in fuel cell mode and > 100 mA/cm2 in liquid hydrocarbon production mode, c) continuous operation of > 100 h, d) cell area > 100 cm2, e) cell cost per rate of product output < 100,000/bpd, f) process intensity of > 0.1 bpd/ft3, g) product yield and carbon efficiency > 50%, and h) volumetric output per cell > 30 L/day
(Invited) Materials Challenges in Advanced Water Splitting Technologies
Authors: Miller Eric Lars , Randolph Katie , Peterson David , Sutherland Erika , Rustagi Neha , Studer Sarah , Klahr Benjamin 
Published: February 2020

The US Department of Energy’s (DOE) Fuel Cell Technologies Office (FCTO) has made significant progress in hydrogen and fuel cell technology advancement and cost reduction. With the rollouts of fuel-cell vehicles by major automotive manufacturers underway, enabling technologies for the widespread production of affordable, renewable, low carbon footprint hydrogen becomes increasingly important. FCTO’s Hydrogen Production Program supports a broad range of H2 production pathways, ranging from nearer-term to longer term technologies. Advanced water splitting (AWS), including electrolysis, photoelectrochecmical and thermochemical routes, is one of the more versatile pathways and can play a significant role. A general overview of FCTO’s H2 Production Program with a focus on advanced water splitting technologies will be provided.
Fundamental materials challenges remain which limit conversion efficiency and durability of AWS H2 production pathways, therefore limiting large-scale technoeconomic viability. Expensive materials are commonly required. Innovations are needed in the development of functional materials and interfaces which address the thermodynamic and kinetic limitations to performance and lifetime at the macro-, meso- and nano-scales. Catalytic advances, especially with respect to low- and non-platinum group metal (pgm) hydrogen and oxygen evolution catalyst materials in both acidic and basic environments, are needed for low temperature electrolysis operation. Examples of ongoing electrolysis and photoelectrochemical R&D will be discussed.
A Pt-Free, Activated Carbon Nanotube Cathode, PEM Water Splitting Electrolyzer
Authors: Das Rajib Kumar , Vasilyeva Svetlana V. , Pulido Ramon M , Pucher Ilaria , Turiansky Mark , Rinzler Andrew G. 
Published: February 2020

Anticipated increases in worldwide energy consumption, the reality of ultimately limited hydrocarbon fuels, as well as their contribution to global warming, have all encouraged the development and commercialization of renewable, carbon neutral, energy technologies. An issue for renewable energy sources like solar, wind and wave energy is their intermittency. An efficient means to overcome this intermittency is to build excess capacity into the generating plants and to use that excess capacity to produce high energy density hydrogen fuel via water electrolysis for on demand reconversion to electrical energy in fuel cells. A major impediment to this solution is that commercial water splitting electrolyzers use scarce and costly precious metal catalysts which make such an energy storage/recovery scheme prohibitively expensive. Alternative, earth-abundant, non-precious metal catalysts are highly desired.
We recently demonstrated that purified single wall carbon nanotubes (SWNT), and select layered graphitic materials, activated by a simple electrochemical process, provide an exceptional non-precious metal electrocatalyst for the hydrogen evolution and the hydrogen oxidation reactions in both acidic and near neutral pH. [1] Here we validate this result for hydrogen evolution in a single-cell PEM electrolyzer. The MEAs studied used Nafion 115 and an IrRuOx anode. Three distinct cathodes were tested: 1) commercially available Pt loaded (3.0 mg/cm2) Vulcan X-72 carbon (for a point of comparison); 2) non-activated SWNTs; and 3) activated SWNTs. In all cases I-V measurements were performed at 80oC. The commercial Pt loaded MEA exhibited the high gas production rates expected from engineered Pt, converting 1.0 A/cm2 at 1.67 V. The non-activated SWNTs yielded very low gas production rates requiring 1.89 V for a current of only 0.040 A/cm2. The activated SWNTs demonstrated a performance completely comparable, at all potentials, with that of the commercial Pt electrode (see Figure), attaining 1.0 A/cm2 at 1.64 V. Ninety hours of operation showed no degradation in the cathode performance.
It has been estimated that a 50% reduction in the cathode Pt used would result in a 15% electrolyzer cost reduction. [2] Our entirely Pt–free electrode using only earth abundant carbon could nearly double that cost saving.
Acknowledgements.
This work was supported by Nanoholdings, LLC.
References:
[1] R. K. Das, Y. Wang, S. V. Vasilyeva, E. Donoghue, I. Pucher, G. Kamenov, H.-P. Cheng, A. G. Rinzler, ACS Nano, 8 (8), 8447–8456 (2014)
[2] K. E. Ayers, E. B. Anderson, C. B. Capuano, B. D. Carter, L. T. Dalton, G. Hanlon, J. Manco, and M. Niedzwiecki, ECS Transactions, 33 (1), 3-15 (2010)

Figure 1
Metal Oxides Supported on Carbon Nanotubes As Bifunctional Electrocatalysts for Reversible Alkaline Membrane Fuel Cells
Authors: Zhao Shuai , Rasimick Brian , Mustain William E , Xu Hui 
Published: February 2020

Carbon nanotubes (CNTs) have received much research interest for energy conversion and storage due to their inherent extraordinary electrical and mechanical properties. Modified CNTs could be used as electrocatalyst supports for the oxygen reduction reaction (ORR) in fuel cells and for the oxygen evolution reaction (OER) for water electrolyzers. Here we present metal oxides supported on CNTs as bifunctional catalysts for reversible alkaline membrane fuel cells.
In order to introduce more active sites and further optimize both the ORR and OER activity in alkaline media, growing transition metal oxides, such as cobalt and nickel oxides, along pre-oxidized CNTs is a state-of-the-art technique. However, in this study, we have discovered that the oxidation degree of the support CNTs (i.e., different oxidizing agents and length of oxidation time) may lead to variable proportions of oxygen functional groups or defective sites, which can further influence the size of metal oxides and their distribution on the CNTs.
As shown in Fig. 1a and b, the support CNTs were pre-oxidized by KMnO4 and concentrated HNO3, respectively, resulting in different densities of metal oxide particles along the tubes. Comparing different length of oxidation time in Fig. 1b and c, the CNTs oxidized by concentrated HNO3 for 0.5 h (Fig. 1c) have much fewer particles anchored than the ones with 6 h oxidation (Fig. 1b). All of these feature changes would have a huge impact on the activity and durability of the bifunctional catalysts.
This work may provide novel perspectives for design of CNTs as support materials in electrochemical applications.

Acknowledgement:The project is financially supported by the Department of Energy’s Fuel Cell Technology Office under the Grant DE-EE0006960.
Figure 1. Metal oxide particle growth along CNTs based on various oxidation degrees

Figure 1
Design of Electrocatalysts for Oxygen Evolution Reaction
Authors: Serov Alexey , Maes Ashley M , Blair Sarah , Artyushkova Kateryna , Atanassov Plamen 
Published: February 2020

Nanostructured materials are widely used in different energy applications: fuel cells, electrolyzers, supercapacitors, Li-ion batteries, etc [1, 2]. Several synthetic approaches can be used for the preparation of CNTs, graphene, etc, such as CVD, exfoliation and other. Herein we report the adopted sacrificial support method (SSM) developed at UNM group [3-4] as a powerful tool for synthesis of materials for oxygen evolution from alkaline solutions.
Several types of 3D structured materials such as carbon nanotubes, oxides, bi- and tri-metallic nickel-based alloys were synthesized by modified SSM. The morphology control was achieved by variation of silica and precursors type, as well as the ratio of silica to the precursor. After successful synthesis of those materials, the sacrificial support (SiO2) was leached using concentrated HF or by 7M KOH. Figure 1 represents a schematic synthesis of CNT-based materials by Sacrificial Support Method.
Figure 1. Schematic view of CNT-based materials synthesis by Sacrificial Support Method.
Different materials with controlled morphology were characterized by XRD, SEM, TEM, BET and XPS methods. Electrochemical performance in the reactions of oxygen reduction, oxygen evolution, was found to be promising for substitution of existing state-of-the-art platinum group metals catalysts.
References:
[1] N. I. Andersen, A. Serov, P. Atanassov “Metal Oxides/CNT Nano-Composite Catalysts for Oxygen Reduction/Oxygen Evolution in Alkaline Media”, Appl. Catal. B: Environmental, 163 (2015), 623-627.
[2] A. Serov, M. Padilla, A. J. Roy, P. Atanassov, T. Sakamoto, K. Asazawa, H. Tanaka "Anode Catalysts for Direct Hydrazine Fuel Cells: From Laboratory Test to an Electric Vehicle", Angewandte Chemie Int. Ed. 126 (39) (2014), 10419–10715.
[3] A. Serov, K. Artyushkova, N. I. Andersen, S. Stariha, P. Atanassov "Original Mechanochemical Synthesis of Non-Platinum Group Metals Oxygen Reduction Reaction Catalysts Assisted by Sacrificial Support Method", Electrochim. Acta (2015) doi:10.1016/j.electacta.2015.02.108
[4] A Zalineeva, A Serov, M Padilla, U Martinez, K Artyushkova, S Baranton, C Coutanceau, Plamen B Atanassov, "Glycerol electrooxidation on self-supported Pd1Sn1-x nanoparticules", Appl. Catal. B: Environmental, 176 (2015), 429–435.

Figure 1
Cobalt-Molybdenum Carbide Hybrids As Efficient Oxygen Evolution Reaction Catalysts for Alkaline Water Electrolysis
Authors: Kim MinJoong , Song DongHoon , Oh SeKwon , Cho EunAe 
Published: February 2020

Increasing demand for clean energy have triggered researches on alternative energy sources and devices to reduce use of fossil fuel. Hydrogen has been considered as one of the most promising energy source for future due to its high energy density and no air pollutant emission. Splitting water into hydrogen and oxygen is an environmentally friendly method for producing hydrogen gas. This technology can store excess electric energy in the form of chemical bonds of hydrogen, which can resolve an issue about surplus electric power of present renewable energy systems caused by irregular energy source such as airflow and sunlight.
Water electrolysis reaction is divided into two half reactions; hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). High overpotential of both HER and OER is the most significant problems to hamper reaction rate and overall efficiency of water electrolysis, especially OER has much higher overpotential than HER. Therefore, recently major efforts have been devoted to exploring active catalysts for the OER in water electrolysis cell.
Among many kinds of candidate materials for OER catalyst, cobalt (Co) and various Co based materials, including nanostructured Co3O4, CoSe2, Co based perovskites, CoP, CoB and Co/N-doped carbon, have drawn much attention for use in the alkaline water electrolysis system. These Co based catalysts have low OER ovepotential in alkaline media comparable with precious metal based catalysts, such as IrO2 and RuO2. However, previous studies has focused mainly on the exploring desirable composites for high OER activity without careful mechanistic study. OER mechanism on Co based catalysts and descriptors for designing more efficient catalysts have been unclear yet.
Herein, we report novel hybrid type catalysts, which composed of Co and molybdenum carbide (Mo2C), as efficient OER catalysts for alkaline water electrolysis, and evaluate the OER mechanism by investigating the effects of surface acidity of the catalysts on the OER activity in alkaline media. Mo2C has very similar electronic structure with platinum (Pt) group metal. So, it can be promising candidate as an efficient electrocatalyst for water electrolysis system. We synthesized Co-Mo2C hybrids using facile solution based process. Synthesized Co-Mo2C hybrids exhibit enhanced activity and durability compared with Co and ruthenium dioxide (RuO2) catalysts in alkaline media (0.1 and 1 M KOH). This result is ascribed to increase in surface acidity by formation of Co-Mo bimetallic surface on the Co-Mo2C hybrids. Increase in surface acidity leads to increase in hydroxide ion (OH-) adsorption on the catalyst surface, which can promote the OER kinetics in alkaline media.
Fig. 1. XRD patterns of Co-Mo2C hybrids.
Fig. 2. OER activities of Co-Mo2C hybrids, Co, RuO2 and Mo2C in 0.1 M KOH solution.

Figure 1
Electrodeposition of Binary and Ternary Ag-Tl-Se Thin Films and Its Possible Application in Photoelectrochemical Conversion of the Solar Energy
Authors: Lucas Francisco Willian de Souza , Mascaro Lucia Helena 
Published: February 2020

Solar energy is inexhaustible, has renewable characteristics, and is considered to be a clean energy source. One of the main energy sources of the future is linked to the efficient utilization of the solar energy by conversion into electric energy (photovoltaic conversion) or for hydrogen fuel producing (photoelectrochemical water splitting). According to our knowledge, the study of the applicability of the binary and ternary Ag-Tl-Se films in solar energy conversion has not been reported, as well as, the fabrication of these films by electrodeposition. In light of this, the present work describes the pulsed- and co-electrodeposition of the binary and ternary Ag-Tl-Se (ATSe) thin films and its applicability in the photoelectrochemical hydrogen production by water splitting. For this, studies of cyclic voltammetry (CV), SEM, EDX, NIR-UV-vis spectroscopy, XRD, Mott-Schottky, and photocurrent were performed. Electrochemical experiments were carried out in a 3-electrode configuration electrochemical cell. Mo-plate (1 cm2) was the working electrode; a Pt-plate was used as the auxiliary, and an Ag/AgCl/Cl-
(sat. KCl) served as the reference electrode (RE). The measurements of comparative photocurrent were performed in 0.5 H2SO4 at -0.60 V and using a solar simulator with AM 1.5G lens, where the light intensity incident on the electrode was adjusted to 100 mW cm-2 (1 sun). From electrochemical behavior characterized by CV, they were chose the deposition potentials of 0.1, -0.15 and -0.4 V vs. RE for ATSe films obtaining. The optimized electrolytic bath was constituted of 0.1 mM AgNO3, 3 mM Tl2SO4, 1 mM SeO2, and 0.5 M Na2SO4/H2SO4, pH = 2. The codeposition (CD) and potential pulsed deposition (PP) were used for study the method effect on the films properties. For CD, the bath temperatures were 25 and 50º C and for PP, 22 factorial experiments were done at 25º C; with pulse duration (2 or 10 min) and number of potential pulses (2 or 3 potentials) as variables. Ten (10) different films were obtained and, from them, it was possible to conclude that the properties are strongly dependent of the deposition potential, bath temperature, growing method and pulse duration. All films were p-type, showed band gap energy from 0.89 to 1.06 eV and presented Ag-Se, Ag-Tl-Se or Tl-Se phases. Interesting results were obtained from photocurrents studies, it was observed that the films composed of a mixing of cubic TlSe and tetragonal Tl2Se phases had higher photocurrent intensity (0.92 mA cm-2) associated the hydrogen production during photoelectrochemical water splitting. Such films were obtained by the CD method, using 1h of electrodeposition at the potential of -0.4 V vs. RE and bath temperature of 50º C. Thus, these studies could help us to observe the potentiality of the Tl-Se films for efficient solar energy conversion, which will be shown.
Tungsten Carbide-Based Catalysts for Oxygen Evolution Reaction in Alkaline Media
Authors: Song DongHoon , Kim MinJoong , Cho EunAe 
Published: February 2020

Hydrogen produced by electrolysis is one of the promising means by which to store electricity coming from renewables and to address its intermittency. With the growing global electricity share from renewable energy sources, large-scale storage systems are required. Alkaline electrolysis can be a sustainable solution for the large-scale energy storage system. However, high overpotential and slow kinetics particularly of the oxygen evolution reaction (OER) still remains as a hurdle to limit efficiency of the system. To enhance efficiency of alkaline electrolysis cells, catalysts which have high electrocatalytic activity for OER should be developed.
Platinum-like behavior of Tungsten carbide in surface catalysis was first reported by Levy and Boudart in 1973[1]. In addition, tungsten carbide was reported to have Pt-like electronic structure by Colton in 1975[2]. After that, tungsten carbide has been studied widely and expected to substitute noble metal catalysts which are used in many electrochemical reactions. Here, we studied tungsten carbide as a support for 3d-transition metals and make bi-metallic surfaces for developing a high activity OER catalyst.
First, WC-Co was synthesized by heat treatment. Carbon nitride (g-C3N4) and tungsten chloride were used as a carbide precursor and cobalt acetate was also used for helping carbonization of tungsten. After heat treatment, acidic leaching process was followed to eliminate cobalt. Through additional mixing with Nickel precursor and heat treatment, Ni/WC was synthesized and to compare electrocatalytic activity Ni/C was also prepared. In addition, many different Ni/WC which have different Ni to WC ratios were synthesized and measured in electrochemical way. Finally, the optimal ratio was determined and it show better electrocatalytic activity than precious catalysts and any other non-noble catalysts.
Cyclic voltammetry was measured to evaluate OER activity in 1 M KOH in potential range from 1 to 1.8 V. Figure 1 shows that pure WC and Ni/C have 394 mV and 413 mV overpotentials at 10 mA∙cm-2 respectively. In Metal/WC cases, Cobalt/WC shows only 417 mV. But Nickel/WC shows 340 mV overpotential at 10 mA∙cm-2 and higher electrocatalytic activity for OER than RuO2 in alkaline media.

η
@ 10 mA cm-2 (mV)

Ni/C
394

WC
413

Co/WC
417

Ni/WC
340

RuO2

355

Table1. Activities for OER at 10 mA cm-2

References

[1] R. B. Levy, M. Boudart, Science, New series, Vol. 181, No. 4099 (1973) 547-579
[2] Richard J. Colton, Jan-Tsyu j. Huang, J.Wayne Rabalais, Chemical Physics Letters, Vol. 34, No. 2 (1975) 337-339

Figure1. Cyclic voltammetry for the oxygen evolution reaction in 1 M KOH of Ni/C, WC, Co/WC, Ni/WC, RuO2

Figure 1