bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bifunctional PGM-Free Hydrogen Evolution and Oxidation Electrocatalysts for AEM Electrodes
Authors: Serov Alexey , Lubers Alia , McKinney Samuel , McCool Geoffrey , Romero Henry , Odgaard Madeleine , Kendrick Ian , Pann Serge , Mukerjee Sanjeev , Capuano Christopher B , Ayers Kathy , Zulevi Barr 
Published: February 2020

Anion Exchange Membrane Fuel Cells (AEMFCs) are a developing alternative to Proton Exchange Fuel Cell (PEMFC) technology. A great advantage of this technology is the possibility of replacing PGM catalysts on both anode and cathode and therefore reducing the costs. For example several PGM-free electrocatalysts have demonstrated superior fuel oxidation performance[1]. In AEM electrolysis both Hydrogen [2] and Oxygen Evolution[3] PGM-free catalysts have been demonstrated. In the present work we present unprecedented performance of a Nickel-based Hydrogen Evolution (HER) catalysts that are bifunctional for the Hydrogen Oxidation (HOR) reaction. These Nickel-based catalysts are multifunctional catalytic systems and rely on g alloying and mixed and low-coverage complementary metal oxides to fine tune surface-electrochemical interactions and reactions. While the goal of the work is to create reversible HER/HOR PGM-free catalysts, the efforts to date were focused on making the most active nickel-based bifunctional HER and HOR catalysts. Next reversible electrodes will be developed and catalyst stability under HER/HOR mode switching will be tested. (ARPA-E OPEN 2015 DE-AR0000688)
A series of nickel-based catalysts were synthesized to create mixed Nickel-alloys and oxides that promote the activation of water and hydroxyl groups on the catalysts. A range of wet-chemical routes was used to produce carbon-supported NiMo, NiCu, and NiMoCu supported on a range of standard and novel Interconnected Mesoporous Carbon™ supports. The materials were characterized through physical parameters such as crystal phase, size, and surface chemistry using XRD, XPS, and Raman Spectroscopy. These materials were evaluated in membrane electrode assemblies [MEAs] using a variety of membranes and ionomers. Unprecedented PGM-free HER performance exceeding 1000 mA/cm2 @ 1.9V and HOR performance exceeding 300 mA/cm2 @ 0.65V were achieved. Reversible MEA structures for these catalysts are still being optimized.

References

[1] U. Martinez, et al Phys. Chem. Chem. Phys. 14 (2012) 5512-5517.
[2] Bates, M. et al J Phys Chem C Nanomater Interfaces. 2015 Mar 12; 119(10): 5467–5477.
[3] Bates, M. et al ACS Catal., 2016, 6 (1), pp 155–161

Figure 1
Pt-Mn/C and Pd-Mn/C Nanoparticles As ORR Electrocatalysts
Authors: Ahmadi Mahdi , Abruña Héctor D. 
Published: February 2020

The sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode remains as one of the main challenges for commercial viability of alkaline exchange membrane fuel cells (AEMFCs). It is therefore, of great interest to explore the development of electrocatalysts with superior activity and stability relative to the conventional carbon supported Pt nanoparticles (NPs).
In this work we have studied the effects and evolution of structure and surface composition of Pt-Mn and Pd-Mn NPs on their electrocatalytic activity for the ORR in alkaline media. Both Pt-Mn and Pd-Mn NPs were synthesized using solvothermal methods and were supported on C via impregnation. In the case of Pt-Mn an ordered intermetallic phase was obtained by heat treatment, while for Pd-Mn NPs heat treatment did not lead to an ordered alloy. We have investigated the crystalline structure of these NPs using X-ray diffraction (XRD) and their size, morphology and composition using TEM/STEM, EELS and EDX. Cyclic voltammetry (CV) and rotating disk electrode (RDE) voltammetry were used to assess their electrocatalytic activity and stability.
The NPs were electrochemically dealloyed in acidic media, through potential cycling, leading to the formation of Pt and Pd shell on PtMn and PdMn core. The dealloyed nanocatalysts exhibited over 400% increase in mass activity and 500% increase in specific activity as compare to Pt/C. The stability of the electrocatalyst was tested after 4,000 potential cycles in alkaline media following the DOE protocol (0.6-1.0 V vs reversible hydrogen electrode). In alkaline media, Mn surface segregation ensued, leading to a lower electrocatalytic activity when compared to the freshly dealloyed catalyst.
(Invited) 100MW-class vanadium flow battery projects in different applications in China
Authors: Huang Mianyan 
Published: February 2020

Vanadium flow battery (hereafter referred as VFB) is one of the most suitable energy storage systems (hereafter referred as ESS) for grid-connected renewable power. And the inherent capitalization potential will improve its commercialization further in the coming future as well. However, comparing to other popular energy storage technology, VRB technology is still lack of experience on large-scale application in different situation.
As the Guideline to Promote Energy Storage System Technology and Industrial Development (the Guideline) issued by five ministries of China (Reform Commission, Ministry of Finance, Ministry of Science and Technology, Ministry of Industry and Information Technology, National Energy Administration) in October 2017 mentioned clearly one of the key commercialized technology should be 100MW VRB-ESS power station, there is several important large-scale flow battery projects promoted in China in 2018, such as 100MW/500MWh peak plant in Hubei, 200MW / 800MWh renewables integration in Liaoning, 200MW / 1,000MWh offshore wind integration in Jiangsu and renewable power integration in Qinghai. Some of the confirmed projects is listed in the following figure.

Figure 1. China’s vanadium flow battery energy storage projects development plan

Several provinces in south coastal area of China, such as Jiangsu, ESS is for peak shifting and arbitrage application as the urgent need of flexible/ Independent peak plants to support the summit power demand in summer. The 100MW/500MWh peak plant in Hubei is mostly to support power requirement of industrial parks. While Qinghai province is the most active place for renewable energy developing and requires large-scale ESS to support grid connection. VRB Energy has got involved closely in most of these projects, and looking forward to share experience and future prospects accordingly.
VRB Energy Operations (Beijing) Co. Ltd., used to known as Pu Neng, the supplier of the 2MW/8MWh VRB-ESS State Grid demonstration site in Zhangbei, Zhangjiakou, China, and 3MW/12MWh VRB-ESS in Zaoyang, Hubei, China. The 3MW/12MWh VRB-ESS in Zaoyang has commissioned in Oct 2018, and provided a technical foundation for the coming 100MW/500MWh project in Hubei. VRB Energy has followed up the 200MW / 1,000MWh offshore wind integration in Jiangsu and wind integration projects in Qinghai closely. Some of the projects are most likely to start construction in 2019.
Additionally, National Development and Reform Commission, state grid, and National Energy Committee issued the ESS price policy to support the ESS development in China. The policy includes increase the power price gap between peak time and off peak time, tax refund, and reward to the ESS project which can provide the good service to state grid, etc. With economic support and practical large-scale projects, the Chinese power market is expected to form a completed market mechanism in the near future.
Linked Donor-Acceptor Systems for Symmetric Nonaqueous Redox Flow Batteries
Authors: Rajewski Andrew , Mann Shane C. , Mortimer Nicholas J. , Dumitrascu Adina , Gillmore Jason G. , Guarr Thomas F. 
Published: February 2020

A series of molecules containing electron donor and acceptor moieties were synthesized and analyzed for potential future use in redox flow batteries (RFBs). These compounds, including D-A, D-A-D, and A-D-A alkyl-linked systems, can exist in at least three stable oxidation states: an oxidized (catholyte) form, a reduced (anolyte) form, and the neutral species. For this study, donors included various organic heterocycles, while acceptors included several imides and diimides. In all cases, cyclic voltammetry revealed highly reversible electrochemical behavior for both the individual redox active moieties as well as for the fully linked system.
This approach provides for the independent optimization of anolyte and catholyte properties, while the covalent linkage results in a symmetric system whereby both RFB half-reactions generate an identical product (the neutral species). In principle, this may allow for elimination of the ubiquitous and expensive ion exchange membrane used in typical RFBs. Because the membrane can account for up to 40% of cell costs, this could represent an important opportunity to improve the economics of employing flow batteries for grid-level energy storage applications.
The synthesis, characterization and preliminary electrochemical investigation of these molecules will be described.

Figure 1
Strategies for Hydraulic Recharge of Zinc-Air Flow Batteries
Authors: Mahlendorf Falko , Fuchs David , Müller Christoph , Heinzel Angelika 
Published: February 2020

The increased use of fluctuating renewable energy calls for efficient, safe and environmentally friendly energy storage solutions. To meet the variable power-, capacity- and profitability requests of mobile and stationary applications, it is necessary to identify promising materials. Zinc-air batteries with specific energy density higher than lithium-ion and low cost, highly available, eco-friendly active materials are suitable to fulfill these requirements. The use of a flow battery type with zinc-particles suspended in alkaline solution (zinc-slurry) in addition with high performance oxygen-reduction electrodes enables the development of high-power zinc-air batteries. This setup also allows the independent scaling of capacity and power. The recharging of this system can be performed due to classical electrical charging or due to a hydraulic recharge by changing the used zinc-slurry with a fresh one.
The cooperative project, ZnMobil, funded by the Federal Ministry of Economic Affairs and Energy in Germany combines the experience of industrial and academic partners (Covestro Deutschland AG; Grillo-Werke AG; VARTA Microbattery GmbH; Accurec Recycling GmbH; Technical University Freiberg, Gottfried Wilhelm Leibniz University Hannover; University of Duisburg-Essen; the fuel cell research center ZBT GmbH) to develop a zinc-air flow battery with high performance and economic efficiency.
Here we present strategies for the hydraulic recharging of zinc-air flow batteries. The battery system consists of a 100 cm² copper plate as current collector for the zinc-suspension electrode and an oxygen reduction electrode with a gas-diffusion layer (supplied by Covestro Deutschland AG). The zinc-slurry contains zinc particles (supplied by Grillo-Werke AG) suspended in alkaline solution (30 wt.-% KOH) and stabilized with polyacrylic acid.
Depth-of-discharge and battery resistance were measured for zinc-slurries in a flow system under regulated conditions. The influence of the depth-of-discharge and several additives on the rheology of the zinc-slurries was evaluated. Depending on the current density and additive selection, it is possible to achieve energies of up to 300 Wh during discharge.
Nitrogen-Doped Carbon Catalysts Modified with Au-M (M = Co, Ni, Cu) Nanoparticles As the Anode Material for Direct Borohydride-Hydrogen Peroxide Fuel Cells
Authors: Balčiūnaitė Aldona , Vaičiūnienė Jūratė , Kruusenberg Ivar , Kaare Kätlin , Volperts Aleksandrs , Dobele Galina , Zurins Aivars , Tamašauskaitė-Tamašiūnaitė Loreta , Norkus Eugenijus 
Published: February 2020

Direct borohydride-hydrogen peroxide fuel cells (DBHPFCs) have several advantages such as high theoretical cell voltage (2.11-3.02 V), high energy density (12-17 kWh kg-1) and, finally, no CO poisoning during their operation. Therefore, anode material is the key factor for complete direct oxidation of borohydride. This study is focused on the synthesis of the nitrogen-doped carbon (N-doped C) catalysts supported Au-M (M = Co, Ni, Cu) nanoparticles using a rapid microwave heating method with the aim to use them as the anode material for DBHPFC. The electrocatalytic activity of the prepared M/N-doped C and Au-M/N-doped C catalysts for the borohydride oxidation reaction (BOR) was evaluated using cyclic voltammetry and chronoamperometry. The direct borohydride-hydrogen peroxide fuel cell was assembled using Pt as the cathode and the prepared M/N-doped C and Au-M/N-doped C catalysts as the anodes. The performance of a DBHPFC operating with 1 M NaBH4 + 4 M NaOH as fuel and 5 M H2O2 + 1.5 M HCl as an oxidant was investigated at different temperatures.
It has been determined that the prepared Au-M/N-doped C catalysts have а higher activity and а better stability for the oxidation of borohydride compared to those of M/N-doped C (M = Co, Ni, Cu) catalysts. The direct borohydride-hydrogen peroxide fuel cell exhibited an open circuit voltage of cа. 1.8 V when the Au-M/N-doped C catalysts were assembled as the anodes.
Investigation of Hydrazine Electro-Oxidation on Zinc-Cobalt Coating Modified with Gold Nanoparticles
Authors: Šimkūnaitė Dijana , Zabielaitė Aušrinė , Balčiūnaitė Aldona , Vaičiūnienė Jūratė , Selskis Algirdas , Vaitkus Rimantas , Tamašauskaitė-Tamašiūnaitė Loreta , Norkus Eugenijus 
Published: February 2020

In this study, the electro-oxidation of hydrazine in an alkaline medium was investigated on the zinc-cobalt (ZnCo) coating, which was deposited on the titanium (Ti) surface and then modified with low amounts of gold nanoparticles (AuNPs). The AuNPs-ZnCo/Ti catalysts with different amount of AuNPs were prepared via a facile electrochemical deposition technique followed by a simple and low-cost galvanic displacement. Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Analysis and Inductively Coupled Plasma Optical Emission Spectroscopy were used for the characterization of the surface morphology, structure and composition of the as-prepared AuNPs-ZnCo/Ti catalysts. Electrocatalytic behavior of catalysts was investigated towards the electro-oxidation of hydrazine in an alkaline medium using Cyclic Voltammetry.
It was found that the AuNPs-ZnCo/Ti catalysts were prepared with the Au loadings of 31, 63 and 306 µg cm-2 after the immersion of the ZnCo/Ti catalyts into the 1 mM HAuCl4 solution for 0.5, 1 and 5 min, respectively. Moreover, the ZnCo/Ti catalysts modified by AuNPs has significantly higher catalytic activity towards the electro-oxidation of hydrazine as compared to that of the ZnCo/Ti catalyst. Additionaly, modification of the ZnCo/Ti catalyst by AuNPs leads to the rather pronounced shift in hydrazine oxidation potential to more negative potential region and is followed by a substantial increase in direct hydrazine oxidation rate as compared to that of the unmodified ZnCo/Ti catalyst.
Fuel Cell Catalysts Encased in 1D and 3D Porous Frameworks
Authors: Farghaly Ahmed A. , Kariuki Nancy N. , Myers Deborah J. 
Published: February 2020

The strong catalyst surface-ionomer interactions in the membrane electrode assembly (MEA) have a negative impact on the electrode performance in the polymer electrolyte fuel cells (PEFCs).1-4 A new series of encased platinum group metal catalysts have been designed in order to minimize the ionomer poisoning of the oxygen reduction reaction (ORR), local oxygen transport issues, and the lack of cathode performance durability. Nanoporous materials have a wide range of technological applications5-9 and are potential candidates to improve the performance of the PEFC catalysts. 1D and 3D ordered inorganic nanoporous structures with well-defined and uniform pores are used to host the catalyst nanoparticles and block the access of the ionomer aggregates to the catalyst surface. The rotating disk electrode (RDE) technique has been used to examine the effect of the host dimensionality on the ORR activity of the newly-designed PEFC catalysts. The effect of the host dimensionality on stability, durability and rate of the electrocatalyst dissolution have been evaluated by means of inductively coupled plasma mass spectrometry (ICP-MS).
References

Kongkanand and M. F. Mathias, J. Phys. Chem. Lett., 7, 1127 (2016).

Subbaraman, D. Strmcnik, A. P. Paulikas, V. R. Stamenkovic, and N. M. Markovic, Chemphyschem, 11, 2825 (2010).

Subbaraman, D. Strmcnik, V. Stamenkovic, and N. M. Markovic, J. Phys. Chem. C, 114 8414 (2010).

C. Cetinbas, R. K. Ahluwalia, N. N. Kariuki, and D.J. Myers, J. Electrochem. Soc.,
165(13), F1051 (2018).

A. Farghaly, R. K. Khan, and M. M. Collinson, ACS Appl. Mater. Interfaces, 10(25), 21103 (2018).

Demir, A. A. Farghaly, M. J. Decuir, M. M. Collinson, and R. B. Gupta, Mater. Chem. Phys., 216, 508 (2018).

Nahar, A. A. Farghaly, R. J. A. Esteves, and I. U. Arachchige, Chem. Mater., 29(18),7704 (2017).

A. Farghaly and M. M. Collinson, Langmuir, 32(23), 5925 (2016).

A. Farghaly, M. Lam, C. J. Freeman, B. Uppalapati, and M. M. Collinson, J. Electrochem. Soc., 163(4) H3083 (2016).

Acknowledgements
This work was supported by the United States Department of Energy, Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office. Argonne is a U.S. Department of Energy Office of Science Laboratory operated under Contract No. DE-AC02-06CH11357 by UChicago Argonne, LLC.
Phosphoric Acid Loss Mechanism of High Temperature Proton Exchange Membranes
Authors: Lee Albert S , Choe Yoong-Kee , Matanovic Ivana , Kim Yu Seung 
Published: February 2020

High temperature-polymer electrolyte fuel cells (HT-PEMFCs) traditionally utilize phosphoric acid-doped polybenzimidazole as proton exchange membrane.1 However, the retention of phosphoric acid within polymer matrix has been pointed out as one of the most critical factors that affect HT-PEMFC durability. Previously, we reported a new HT-PEMFC system in which a quaternary ammonium-functionalized polymer imparted a stronger ionic interaction which we deemed “ion-pair coordination” with phosphoric acid compared with that of polybenzimidazole,2 giving rise to improved water tolerance. In this study, we use a combination of 31P NMR and DFT computations to compare the ionic interactions between representative small molecule organic bases, benzimidazole or tetramethylammonium hydroxide, with phosphoric acid and water. Based of these results, we propose a new phosphoric acid loss mechanism in which the strongly interacting ion pairs can increase the phosphoric acid partition composition towards accommodating more phosphoric acid for better phosphoric acid retention.
References

Li, J.O. Jensen, R.F. Savinell, N.J. Bjerrum, Prog. Polym. Sci., 2009, 34, 449-477.

-S. Lee, J.S. Spendelow, Y.K. Choe, C. Fujimoto, Y. S. Kim, Nature Energy, 2016, 1, 16120-16124.
(Invited) Electronic Properties of ABO4 Photo-Catalysts Under Nb-Substitution and Phase/Pressure-Related Distortions
Authors: Huda Muhammad N , Bainglass Edan , Sarker Hori Pada , Rao Pratap 
Published: February 2020

Both SbTaO4 and SbNbO4 in the orthorhombic α-Sb2O4 phase have demonstrated pure water splitting as photo-catalysts. Previous experimental studies have shown a significant difference in reported bandgap values for SbTaO4 such as 3.71 eV and 2.28 eV. We have studied SbTa1-xNbxO4 (x = 0, 0.25, 0.5, 0.75, 1) in the tetragonal, orthorhombic, and monoclinic phases. The resulting Sb3+
M
5+O-2
4 material can be classified as a ns2
md0 ternary metal oxide. We have studied the effects of structural symmetry related distortions on the band gaps and overall energetics of SbMO4 compounds (M = Ta, Nb). Evolution of the electronic structures was studied as one transitions from a system of 4d bands to 5d bands, and whether this has any effect on the Sb oxidation state or its lone pair s electrons. From the atomic point of view, electronic correlation energy is higher in Ta 5d than in Nb 4d, and Nb 4d band is higher in energy than Ta 5d. These were examined in terms of oxidation states in their respective solids. We look at the effects of increasing Nb concentration on the electronic structure of SbTa1-xNbxO4 alloy with emphasis on polyhedral and overall cell distortions. We decouple the effects caused by the presence of different nd cations from those caused by distortions and reorientation of various polyhedra. BiVO4 Belongs to the same group of materials; we will also present the electronic structure changes caused by Nb incorporation in BiVO4 and the application of external pressure. Through the analyses of the chemical-potential landscape, we have determined the single-phase stability zone of BiVO4 with the Nb doping. Application of external pressure improved the single-phase stability zone. We have also focused on the local structural distortions near the Nb doping site, especially on the BiO8 octahedra. We have shown here that pressure-induced symmetrization of BiO8 dodecahedron could lower the electron’s effective mass and therefore can help to improve the photo-conduction property of BiVO4.
This work is supported by NSF-award # 1609811. We also acknowledge the computational time from Texas Advanced Computing Center (TACC).
Hydrogenation of Carbonyl Compounds over Pd in Aqueous Phase Under Charged Conditions: Role of Organic Molecular Structure
Authors: Meyer Laura C , Sanyal Udishnu , Camaioni Donald M , Stoerzinger Kelsey A , Gutiérrez Tinoco Oliver Y , Lercher Johannes A 
Published: February 2020

Electrocatalytic hydrogenation (ECH) is a promising approach for energy conversion utilizing renewable electricity to transform biogenic carbon sources to more useful feedstocks. Carbonyl groups are one of the most abundant and highly reactive functionalities of bio-derived molecules. Recent studies of benzaldehyde ECH showed a higher activity of C-supported Pd compared to other metals, i.e., Pt, Rh, Ni.
In the present study we explore this catalytic chemistry further, comparing the reduction of aromatic and aliphatic carbonyl compounds on Pd/C with the aim to understand the influence of molecular structure on the reaction pathways and selectivity in ECH. The experiments were conducted over the potential range of -0.1 VRHE to -0.3 VRHE at low temperatures and atmospheric pressure. The aromatic carbonyl compounds benzaldehyde, acetophenone, and furfural showed significant reactivity toward hydrogenation, whereas the aliphatic carbonyl compounds butyraldehyde and cyclohexanone exhibited small or negligible reduction rates. Under these conditions, the reactive carbonyls all reduced to alcohols without secondary products. The Figure demonstrates the result of the cathodic potential on the reduction of carbonyls. The H2 evolution reaction (HER) was the prevalent side reaction during ECH and increased exponentially with negative potential. Benzaldehyde reduction rates were highest and increase linearly, followed by acetophenone reduction rates, which plateaued at -0.2 VRHE. Furfural reduction rates increased exponentially with cathodic potential albeit with lower values than benzaldehyde and acetophenone. Rotating disk electrode (RDE) experiments showed that the presence of organic compounds affects charge transfer processes to an extent that is a function of the molecular structure. These results indicate a competitive adsorption of organic compounds and hydrogen on Pd and highlight the dependence of hydrogenation rates, HER rates and charge transfer on the molecular structure, which determines the adsorption strength of the organic molecules. TCH rates are plotted against their OCV values in the Figure, showing lower rates than ECH. This allows to conclude that an electrochemical mechanism is dominating the reaction under cathodic bias. The data agrees well with a kinetic model, where the first hydrogen addition (through a proton coupled electron transfer) is the rate determining step.
This work helps to understand the influence of molecular structure on the rates of electrocatalytic hydrogenation of organic compounds and simultaneous H2 evolution. Our studies will enable predictive models - based on common principles in catalysis - to be applied to other metals and organic compounds.

Figure 1