bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Active and Durable Ceramic Carbide and Nitride Cathode Materials for PEM Fuel Cells Synthesized Via Facile Methods
Authors: Lori Oran , Elbaz Lior 
Published: February 2020

Considering the need for alternative and efficient energy sources, fuel cells appear to be a viable and cost-effective solution. One of the more acute setbacks in the commercial distribution and utilization of this technology is the lifetime of the fuel-cell which is mostly limited by the stability of the electrode.1 In this regard, carbon-based materials are not suitable as an electrode material since carbon undergoes severe corrosion in fuel-cell ambience.
In the quest to find more durable alternatives, Nano-structures of ceramic carbides and nitrides such as Mo2C, TiN and more were synthesized via facile solid-state synthesis paths and utilized as support material for the deposition of Pt catalyst in order to be studied as durable, corrosion-resistant ceramic-based systems for the oxygen reduction reaction (ORR). Catalyst integration techniques that further increase the stabilization and corrosion-resistance of the catalyst-support systems were employed as well. Concurrently, these techniques also enable the usage of low Pt loadings in order to satisfy the economical issues arising due to the use of precious metal catalysts (PMC).
The synthesized ceramic compounds were found to be devoid of free carbon despite their organic precursors, making them potentially compatible as fuel cell electrode material.
Furthermore, they were found to be superior at almost every fuel cell-related parameter than any other equivalent carbonaceous systems examined. Parameters like ORR performance showed circa 10% more positive half-wave value, and corrosion resistance tested using accelerated stress tests (ASTs) showed about 40% better initial ECSA preservation. Additionally, even the post-AST Pt/ceramic systems were found to show more positive half-wave potential (around 30 mV) over the pre-AST carbon-based equivalent.2

The corrosion mechanism of these ceramic-based systems is also being under investigation which suggest the formation of several oxide species that tend to dissolve in the aqueous medium over time.

O. Lori and L. Elbaz Catalysts, 2015, 5, 1445.

O. Lori, S. Gonen and L. Elbaz, Journal of The Electrochemical Society, 2017, 164, F825-F830.
A Hybrid Organic Linker Forms an Efficient Non-Precious-Metal-Based Metal–Organic Coordination Network Porous Material for Oxygen Electroreduction Reaction
Authors: Kongi Nadezda , Ping Kefeng , Bhadoria Rohit , Kook Mati , Vlassov Sergei , Tammeveski Kaido , Starkov Pavel 
Published: February 2020

Proton exchange membrane fuel cells (PEMFCs) are one of a few technological solutions that address both alternative energy demands and sustainability (by virtually converting dihydrogen and O2 to water).1 With the prices of precious metals (e.g. Pt, Pd, Au) remaining high, the electrodes’ materials for this type of devices have to be cost-efficient in order to drive the technology into the marketplace. While the state–of–the–art solutions remain being platinum-based and carbon-supported, the alternatives are highly sought after. One of the potential solutions recognized by the community is to use earth-abundant metal (Ni, Co, Fe)-based systems.
The design of efficient functional materials often requires exploration of new modes of connectivity. In porous coordination materials, the nature of an organic linker plays a crucial role. Metal–organic frameworks have recently shown a well-received attention in addressing the need for new solutions in energy conversion and storage.2-4

While symmetric linkers are widely employed, we show that a non-symmetric, electron-rich merged scaffold allows for fabrication of crystalline and amorphous metal-organic coordination networks. We have further utilized them to fabricate a non-supported material that shows high electrochemical oxygen reduction performance in alkaline medium with the onset and half-wave potential higher than that of the state-of-the-art 20 wt% Pt/C catalyst.

References

M. K. Debe, Electrocatalyst approaches and challenges for automotive fuel cells, Nature, 486
, 43 (2012).

H. B. Wu and X. W. Lou, Metal-organic frameworks and their derived materials for electrochemical energy storage and conversion: Promises and challenges, Sci. Adv., 3
, eaap9252 (2017).

P.-Q. Liao, J-Q. Shen, and J.-P. Zhang, Metal–organic frameworks for electrocatalysis, Coord. Chem. Rev., (2018) in press, DOI:10.1016/j.ccr.2017.09.001.

M. Shao, Q. Chang, J.-P. Dodelet, and R. Chenitz, Recent advances in electrocatalysts for oxygen reduction reaction, Chem. Rev., 116, 3594 (2016).
(Invited) U.S. DOE Early-Stage Alkaline Membrane Fuel Cell R&D
Authors: Thompson Simon T. , Ho Donna , Papageorgopoulos Dimitrios C 
Published: February 2020

The U.S. Department of Energy (DOE) supports research, development, and demonstration of fuel cell technologies for transportation, stationary, and early market applications. Fuel cell research and development (R&D) efforts predominantly concentrate on R&D of fuel cell stack materials and components to achieve low-cost, high performance fuel cell systems, and include longer term technologies, such as alkaline membrane fuel cells (AMFCs). More favorable oxygen reduction kinetics and increased platinum group metal (PGM)-free catalyst stability at high pH conditions have invigorated interest in alkaline membrane fuel cells as an alternative to polymer electrolyte membrane fuel cells (PEMFCs), on which fuel cell electric vehicles currently available for retail sale are based. The catalyst accounts for >40% of the projected high-volume stack cost in PEMFC electric vehicles, owing largely to the inclusion of PGMs [1]. Achieving cost competitiveness with internal combustion engine vehicles will be expedited by eliminating PGM-based catalysts; AMFCs offer a promising route for successfully incorporating state of the art PGM-free catalysts into membrane electrode assemblies (MEAs).
Alkaline membrane R&D is targeted to increase the operating temperature and humidity ranges of fuel cells while improving conductivity and to increase membrane mechanical, chemical, and thermal stability with diminished fuel crossover. In 2016, an expert-led workshop on alkaline electrolyte membranes (AEMs) was convened by the DOE based on intense interest in the field and recent advances including performance of >1 W/cm2 in H2/O2 MEA testing [2]. There was consensus on the need for AEM-specific standardized protocols and testing and for further improvement in MEA performance. In order to accelerate materials development within the field, the DOE has set an AMFC-specific 2020 technical milestone of PGM-free MEA demonstration of >600 mW/cm2 performance in H2/air.
Stable, conductive polymer materials and durable hydrogen oxidation catalysts are key to realizing commercially relevant AEMFCs. Existing efforts in the DOE R&D portfolio include increasing performance and durability in perfluorinated and hydrocarbon-based ionomers, increasing cation group stability, diminishing catalyst deactivation due to ionomer-catalyst interaction, and PGM-free MEA performance of 350 mW/cm2.
Going forward, the profound lack of readily available, stable AEMs or ionomers for high pH MEAs must be addressed in order to expand entry into the field and foster more rapid progress in AEMFC development.
References:
[1] B. D. James, J. M. Huya-Kouadio, C. Houchins, D. A. DeSantis, "Mass Production Cost Estimation of Direct H2 PEM Fuel Cell Systems for Transportation Applications: 2017 Update," Strategic Analysis, Inc., 2017.
[2] U.S. Dept. of Energy. "2016 Alkaline Membrane Fuel Cell Workshop Report," Phoenix, AZ. April 1, 2016.
Synthesis and Characterization of Platinum-Praseodymium Oxide Nanocatalysts for Methanol Oxidation
Authors: Valk Peeter , Nerut Jaak , Kanarbik Rait , Aruväli Jaan , Paiste Päärn , Tallo Indrek , Lust Enn 
Published: February 2020

Direct methanol fuel cells (DMFCs) are promising energy conversion devices, which can provide high efficiency and energy density, and as such, have been studied intensively. Due to the poisoning of Pt catalysts during methanol oxidation, various co-catalysts have been studied. Ruthenium has been studied extensively and good results have been obtained. More recently various oxide materials have been proposed and studied. Of these materials, rare earth metal oxides have been shown to be promising co-catalysts, although of the various oxides, CeO2 has perhaps received most attention.
In this study, praseodymium oxide containing catalyst materials have been synthesised and characterized. Praseodymium oxide containing nanocatalysts were obtained via deposition of praseodymium hydroxide onto a carbon support material and calcination of the resulting material. Thereafter, platinum nanoclusters were deposited onto the praseodymium oxide containing composite material by impregnation of the Pt precursor into the support material and further reduction with hydrogen.
The studied materials were electrochemically characterized using rotating disk electrode, cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy methods. Physical properties of the materials were characterized using X-ray diffraction, thermogravimetric analysis, scanning electron microscopy with EDX, inductively coupled plasma mass spectrometry and specific surface area measurements.
The studied materials exhibit high currents for methanol oxidation even at low Pt loadings. Compared to a commercial Pt-C(Vulcan) material, the overpotential was drastically reduced, and the peak potential for methanol oxidation is at E = 0.15 V vs mercury-mercurous sulfate electrode.
The good results of the study are a continuation of the investigation of nanocatalysts containing rare earth metal oxides for electrooxidation of alcohols.
Acknowlegements
This work was supported by the EU through the European Regional Development Fund Project TK141 “Advanced materials and high-technology devices for energy recuperation systems” (2014-2020.4.01.15-0011) and by the Estonian Research Council (institutional research grant IUT20-13, and PUT1581). P. Valk thanks Estonian Students Fund in USA for financial support.
Uio-66 As an Effective Support of Metal Oxides for Oxygen Evolution Catalysis
Authors: Andrade Angela Macedo , Liu Ziqi , Grewal Simranjit , Bai Seoung Jai , Lee Min Hwan 
Published: February 2020

The most well-known electrocatalyst for oxygen evolution reaction (OER) have been noble metals or combination of them such as ruthenium, and/or iridium.1 Due to their cost and scarcity, however, there is a persistent search for alternative materials. Metal organic frameworks (MOFs) have recently attracted significant attention due to their versatility and stability in wide range of environments that allow for post-synthetic modifications and functionalization. This tunability of MOFs has given way to the development of exceptional electrocatalyst that can have comparable performance to noble metals, and mitigate the issues found in them.2

In this study we investigated the OER performance of the zirconia-based MOF, UiO-66, as a support for metal oxides such as CoOx, MnOx and TiOx. UiO-66 has previously been used as a support for catalyst such as molybdenum, and has rendered comparable catalytic performance to that of platinum carbon for the hydrogen evolution reaction (HER).3 Having a MOF support for catalysts, such as metal oxides, can be ideal due to the well-defined MOF surrounding that will allow them to function as catalyst, but protect them from agglomeration at high temperatures.
We synthesized samples containing UiO-66, graphene oxide (GO) and cobalt oxide (CoOx) using the solvothermal method. Electrochemical characterization revealed that the hybrid CoOx@UiO-66/GO affords an excellent catalytic activity for OER with an onset potential of 1.6 V versus RHE, comparable to that of Ir and Ru-based catalysts.2 Additionally, this study contains discussions on the factors of the high OER activity through a series of physical characterizations of the hybrid catalyst.

References:

Lee, Y., Suntivich, J., May, K. J., Perry, E. E. & Shao-Horn, Y. Synthesis and Activities of Rutile IrO 2 and RuO 2 Nanoparticles for Oxygen Evolution in Acid and Alkaline Solutions. doi:10.1021/jz2016507

Aijaz, A. et al. Co@Co3O4 Encapsulated in Carbon Nanotube-Grafted Nitrogen-Doped Carbon Polyhedra as an Advanced Bifunctional Oxygen Electrode. Angew. Chemie - Int. Ed.
55, 4087–4091 (2016).

Yang, J. et al. Porous Molybdenum Phosphide Nano-Octahedrons Derived from Confined Phosphorization in UIO-66 for Efficient Hydrogen Evolution. Angew. Chemie - Int. Ed.
55, 12854–12858 (2016).
(Invited) Japan’s Current Policy and Activity Toward Realizing a Hydrogen Based Society
Authors: Ohira Eiji 
Published: February 2020

The presentation shows Japan’s challenge to realize hydrogen based society including up to dated policy, market information, and RD&D activities.
To tackle several social agendas such as energy security, climate change, etc. Government of Japan has been strongly promoting activity toward realizing hydrogen based society. On December 26, 2017, the Japanese Government concluded the “Basic Hydrogen Strategy” to accomplish a world-leading hydrogen-based society.
The strategy shows future visions toward 2050 and also serves as an action plan to accomplish the visions by 2030. The strategy sets a goal that Japan should reduce hydrogen costs to the same level of conventional energy and to achieve the goal, provides integrated policies across ministries ranging from hydrogen production to utilization under the common goals.
Fuel cell applications has been penetrated to Japanese market. Total installation number of residential fuel cell has reached over 250,000. About 2,200 fuel cell vehicles have been sold and 100 hydrogen refueling stations have been operated.
To enhancing utilization of hydrogen technology, the New Energy and Industrial Technology Development Organization (NEDO) has been conducting comprehensive technology development and demonstrative research programs. The most recent result from NEDO’s program on fuel cell technology will be addressed. Also current status of NEDO’s demonstration project on hydrogen gas turbine, large scale hydrogen supply chain, power to gas will be introduced. In addition, NEDO has been developing a technology roadmap on hydrogen and the roadmap will be introduced.
Ni-Fe Oxide Quantum Dots Anchored on Carbon Nanotubes As a Catalysts for Oxygen Reduction/Evolution Reactions for Metal-Air Batteries
Authors: Xu Nengneng , Wang Yu-Dong , Zhou Xiao-Dong , Qiao Jinli 
Published: February 2020

Metal-air batteries, such as zinc-air batteries and magnesium-air batteries, can potentially enable a widespread implementation of clean renewable energy. The primary limitations of metal-air battery are the sluggish electrocatalytic kinetics on the air side and poor stability of electrode performance. Hence, highly efficient and stable Fe/Ni-based electrode can simultaneously address these challenges. In this work, a novel ORR and OER catalyst, NiFe2O4 quantum dots (QDs) is synthesized, which are self-assembled on carbon nanotubes (CNTs). A composite of NiFe2O4(QDs)/CNTs exhibits a superior bifunctional oxygen electrocatalytic activity with a low the potential gap between ORR and OER (ΔE: 0.9 V). The NiFe2O4(QDs)/CNTs electrode displays a high power density and a high specific capacity in both zinc-air batteries and magnesium-air batteries at ambient conditions. Particularly, the rechargeable zinc-air batteries show a low charge-discharge voltage gap of only 0.62 V and long-term rechargeability for more than 800 hours. The remarkable performance of NiFe2O4(QDs)/CNTs can potentially facilitate the largescale implementation of renewable energy storage by rechargeable metal-air batteries.
Keywords: NiFe2O4 quantum dots, ORR, OER, Low voltage gap, Metal-air battery
Novel Red-emitting Phosphors: Synthesis, Photoluminescence and Theoretical Calculations
Authors: Liu Wei-Ren 
Published: February 2020

A series of novel red-emitting Sm3+-doped phosphors were synthesized by a conventional solid state reaction. The crystal structure and atomic coordinates of was characterized by Rietveld refinement. Luminesce properties of as-synthesized Sm3+-doped phosphors are carried out by PL/PLE, decay life time, thermal quenching as well as reflectance spectrometer and LED fabrications. The results indicate that composition-optimized phosphor exhibits orange-red emission peaks located on 564, 601, 608 and 648 nm attributed to the transitions of 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 →6H7/2

and 4G5/2 → 6H9/2, respectively. The results of LED fabrication by combing 380 chip and blue/green phosphors are demonstrated in this study. Finally, from viewpoint of theoretical calculations, band structure and density of state for host and Sm3+-doped phosphor are studied by first principles calculations. All the results indicate that our phosphors could be a potential material for white light-emitting diodes.
FIG. 1 (a) Electroluminescence spectrum of BaMgAl10O17:Eu2+, Ba2SiO4:Eu2+ and as-synthesized red phosphor with 380 chip. Inset: photo image of LED device derived at 20 mA; (b) CIE coordinates of red phosphor excited at 365 nm. Inset: red phosphor image in UV box under 365 nm excitation.

References

[1] Irish Valerie B. Maggay, Kai-Yuan Yeh, Bingfu Lei, Mikhail G. Brik, Michal Piasecki and Wei-Ren Liu,* “Luminescence properties of Eu2+ - activated NaCaBeSi2O6F for white light-emitting diode applications,” Mater. Res. Bull.,
100, 26-31 (2018).
[2]Chun-Ting Chen, Maxim S. Molokeev, Tzu-Jen Lin and ± “Synthesis, luminescent properties and theoretical calculations of a novel orange-red-emitting Ca2Y8(SiO4)6O2:Sm3+ phosphors for white light-emitting diodes applications,” Dyes and Pigments, 150, 121-129 (2018).
[3] Jy-Chern Chang, Haikun Liu, Pin-Chun Lin, Libing Liao and Wei-Ren Liu,* “Intense broad-band absorption and efficient blue-emitting SrCa2MgSi2O8:Eu2+ phosphor for high color-rendering white LED Applications,” J. Alloy and Compds., in press.
The Role of Li Salt in Highly Concentrated Electrolyte of Lithium Sulfur Batteries
Authors: Noh Hyungjun , Kim Hee-Tak 
Published: February 2020

Recently, the properties of electrolyte have been reported as powerful parameter affecting the behavior of Li ion battery. Among them, Li salt has been regarded as important parameter that can influence not only the battery performance but also Li metal stabilization. In the same line with this view, highly concentrated salt has been attracted because of its various unusual functionalities such as high electrochemical stability for advanced lithium ion battery. However, even though highly concentrated electrolyte has many advantages for advanced Li ion batteries, it cannot be applied in Li-S batteries due to the limited solubility of sulfur related species.
In this paper, we applied different two types of salt in highly concentrated electrolyte for Li-S batteries. The combination of salt with electro-donating property changed the Li2S deposition chemistry and increased equilibrium concentration of polysulfides in electrolyte as well as Li metal stabilization. This unique effect of salt was clearly demonstrated using ex-situ analysis including Uv-vis, Raman spectroscopy with combination of computational simulation. This finding offers understanding about peculiar solvation structure under highly concentrated electrolyte and novel strategy for modulating electrochemical reduction mechanism in highly concentrated Li-S batteries
A Study on Overcoming the Inert Capacity of Polymer Sulfide Electrode with Conducting Materials
Authors: Park Jinkyu , Kim Seokwoo , Jin Dahee , Oh Jeonghun , Yoon Byeolhee , Choi Junyoung , Jo Hearin , Lee Yong Min , Ryou Myung-Hyun 
Published: February 2020

Demand and use of electric vehicles (EVs) is rapidly increasing due to environmental pollution problems. However, electric vehicles have a big disadvantage of short mileage. In order to overcome these disadvantages, a large amount of batteries were mounted on the automobile to increase the amount of absolute energy. However, such a solution does not increase the fuel efficiency so much as the weight of the automobile increases. Therefore, a battery using a high energy density active material should be applied to lower the weight of the battery and increase the energy density. Recently, Li-S batteries among high-energy density next generation secondary batteries have a high capacity of 1675 mAh / g, and are being studied because of their advantages of being cheap and environmentally friendly. However, due to polysulfide elution, shuttle phenomenon and low conductivity, there is a problem of capacity reduction and cycle performance deterioration.
Recently, much research has been conducted to solve the problem of inhibiting the dissolution of polysulfide. Among previous works, there have been studies to synthesize polymeric active materials by adding organic sulfur additive to molten sulfur. The synthesized active materials inhibited the elution of the polysulfide and confirmed the improvement of cycle performance.
In this study, the polysulfide elution and shuttle phenomenon inhibited by using the active materials used in the above - mentioned studies and the electrochemical characteristics of the electrodes prepared by using two conductive materials separately were analyzed.
Nanoporous Carbon Coated Sb Anode for High Performance K-Ion Batteries
Authors: Verma Rakesh , Ki Hyeong-Seo , Park Chan-Jin 
Published: February 2020

Potassium-ion batteries (PIBs) can be regarded as one of the most emerging energy storage devices alternative to current Li-ion batteries (LIBs), due to their resourceful, environment-friendly, and economic merits. For anode in PIBs, the recent researches have mainly focused on carbonaceous materials due to their high electric conductivity and low cost. Nevertheless, the capacities of carbonaceous materials are not satisfactory and cannot meet the growing demand for higher energy density batteries, which have seriously hindered their practical application. Recently, the alloy type materials such as Sn, Sb, Ge, and P have attracted much attention due to their superior capacity. Among various alloy type materials, Sb is a potential anode material for PIBs with a high theoretical capacity of 660 mA h g-1. However, a large volumetric change of ~400% during the alloying/dealloying processes may cause the fracture of active material and loss of electrical contact, leading to rapid capacity fading. To address this issue, numerous strategies have been proposed to mitigate the stress induced by volume change and enhance the electrochemical performance of Sb-based electrodes. An efficient and simple strategy is to synthesize carbon coated porous morphology and structure in nanoscale.
In the present study, we have successfully prepared a Nano porous Sb/C composite through a simple carbothermal reduction method. Fig.1 represents the XRD pattern and morphology of the synthesized nanoporous Sb/C composite. Further, the electrochemical performance of nanoporous Sb/C electrode was studied for the application as an anode material for PIBs. The nanoporous Sb/C electrode exhibited excellent electrochemical characteristics in terms of high specific capacity, excellent cyclability, and good rate capability. The superior performance of Sb/C electrode is attributed to the original high capacity of Sb active materials as well as the mitigation of stress and the improvement of electrical conductivity inside electrode by employing carbon coating. The effect of the alloying/dealloying process on the crystal structure of Sb/C was examined by the ex-situ XRD patterns recorded in various stages of discharge and charge. We consider that this work can provide a guideline to open up new research opportunities in the development of PIBs.

Figure 1