bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalysts for the Electrochemical Conversion of Carbon Dioxide
Authors: Billy Joshua , Co Anne 
Published: February 2020

Currently, there are no large, commercial processes that convert carbon dioxide back to useful chemicals, save for the water-gas shift that leads to the Fischer-Tropsch process, but both of these reactions require a large amount of energy input. Simpler methods exist, such as the electrochemical conversion of carbon dioxide, which can be performed in aqueous solution at room temperature1. This carbon dioxide utilization pathway is not yet fully developed for several reasons: lack of a selective and robust catalyst, large energy input required for desirable products, and low current densities (low yields)2. All of these issues are being addressed by researchers in the field.
Copper metal has been found to produce the most desirable products, hydrocarbons, which can be used as fuel3. High surface area nanoporous copper catalysts were prepared using an in-house method. Galvanic displacement reactions using aqueous transition metal salt solutions were used to create nanoporous copper catalysts with a coating of a second transition metal. Electrolysis was conducted using a custom built electrochemical cell and a Princeton Applied Research potentiostat. CO2 reduction products were analyzed in-situ using a gas chromatograph with a mass spectrometer and thermal conductivity detectors. Liquid products were analyzed using nuclear magnetic resonance.
Results show unique selectivity for all variations of nanoporous bimetallic copper catalyst tested. The pure nanporous Cu preferentially producing ethylene and ethane with very minimal methane. On a typical polycrystalline copper catalyst, methane and ethylene are the majority hydrocarbon gases while ethane is rarely observed. A significant amount of formate was produced on nanoporous Cu, reaching 10% faradaic efficiency at potentials as low as -0.55 V vs RHE. Selectivity of the catalysts can be significantly altered on bimetallic Cu surfaces. Substantial increase in ethylene and ethane is observed and greater amounts of ethanol and propanol (~5% FE each) were produced. Preliminary experiments using 13CO2 saturated solution have been performed and may provide insight into CO2 reduction pathways. Using mass spectroscopy and NMR, reaction products were monitored. Product species containing the 13C isotope were observed for all CO2 reduction products and a comparison to 12CO2 experiments was made. Differences in the 13C/12C ratio may provide clues as to the carbon species responsible for the measured products.

References

1. Y. Hori, K. Kikuchi and S. Suzuki, Chemistry Letters, 1985, 1695-1698.
2. Carbon Dioxide Utilization: Electrochemical Conversion of CO2 - Opportunities and Challenges, DNV, 2011.
3. Y. Hori, K. Kikuchi, A. Murata and S. Suzuki, Chemistry Letters, 1986, 897-898.
4. K. P. Kuhl, T. Hatsukade, E. R. Cave, D. N. Abram, J. Kibsgaard and T. F. Jaramillo, Journal of the American Chemical Society, 2014, 136, 14107-14113.
Artificial Photosynthesis: Photocatalytic Fixation of CO2
Authors: Zhou Yong , Wu Congping , Zou Zhigang 
Published: February 2020

In recent years, the increase of carbon dioxide (CO2) in the atmosphere has become a global environmental issue because of the serious problems, such as the “greenhouse effect”. The idea of mimicking the overall natural photosynthetic cycle of chemical conversion of CO2 into useful fuels has been consistently gaining attention for more than thirty years. Such artificial photosynthesis allows direct conversion of CO2 and water on photocatalysts into valuable hydrocarbon using sunlight at room temperature and ambient pressure to serve to reduce atmospheric CO2 concentrations while providing on a renewable carbon fixation and energy storage.
In this presentation, we will report the utilization of solar energy to highly efficient conversion of CO2 into renewable hydrocarbon fuel over structured nanomaterials. The geometric shape and exposure of specific crystal planes of the nanostructures as well as combination of graphene as a good electron collector and transporter are a requisite for the high level of photocatalytic reduction of CO2.
[1] W. G. Tu, Y. Zhou, Z. G. Zou, Adv.
Mater. 2014, 26, 4607 (review article)
[2] Q. Liu, Y. Zhou, J. H. Kou, X. Y. Chen, Z. P. Tian, J. Gao, S. C. Yan, Z. G. Zou J. Am. Chem. Soc.
2010,
132, 14385.
Renewable H2 Evolution Efficiency and Corrosion Tolerance of 5 Nickel Phosphide Crystalline Phases
Authors: Laursen Anders B. , Liu Bin , Izett Edward , Patraju Kelly , Whitaker Mariana J , Retuerto Maria , Sakar Tapati , Yao Nan , Ramanusjachary Kandalam , Greenblatt Martha , Dismukes G Charles 
Published: February 2020

Renewable (electrical) energy from sources like photovoltaics and windmills, which are inherently intermittent, requires significant storage of the energy. Hydrogen(H2) from electrochemical water splitting offers a nearly unlimited renewable resource for energy storage and bulk chemical processing. Platinum(Pt), although scarce, remains the archetypical electrocatalyst for acidic H2 evolution. While several non-noble metal catalysts have been found, they all, except one, perform worse than Pt. Since 2013, many transition metal phosphides have been reported as possible replacements for Pt. Our group reported that one particular nickel phosphide phase, Ni5P4, is comparable to Pt in activity (geometrically) as well as corrosion resistant in both strong acid and alkali during electrocatalysis. Here, we will present comparative studies of the activity, efficiency and corrosion stability of five crystalline NixPy phases during electrocatalytic H2 evolution. Supported by Rutgers, NATCO and NSF-CBET/DOE.

Figure 1
Ultra-Low NO2 Detection By Gamma WO3 Synthesized By Reactive Spray Deposition Technology
Authors: Jain Rishabh , Lei Yu , Maric Radenka 
Published: February 2020

A porous tungsten oxide (WO3) film based NO2 sensor was developed by a one-step flame based process called Reactive Spray Deposition Technology (RSDT). The RSDT process allows the flexibility to create monoclinic gamma-WO3 with control of the particle size, porosity and thickness of the film. This nano-crystalline WO3 film was deposited directly on gold interdigitated electrodes. The sensor response was measured at the parts per million (ppm) level, (0.17-5 ppm in air at 100% relative humidity) at different operating temperatures (250-350°C) to determine the optimum working temperature. The sensitivity was found to be maximum at 300 °C. The sensors showed a relatively fast response time (∼7s) and recovery time (∼5 min), respectively. The stability of the sensor was evaluated for 300 h in 0.5 ppm NO2 in air at 100% relative humidity (2000 response-recovery cycles). The sensor was stable up to 6 days (~150 h) of continuous operation and degraded between 150 to 300 h. In order to check the selectivity, the sensor was also tested for 10 ppm acetone, 100 ppm ethanol, 10-100 ppm H2, and 10 ppm isoprene. Interference was negligible with 10 ppm acetone, 100 ppm ethanol, 10 ppm H2 and humidity; however, it was significant with 10 ppm isoprene and 100 ppm H2. We have also compared the test data of this gamma WO3 based NO2 sensor prepared by RSDT with the results reported in the literature. The morphology and surface properties of the WO3 film were investigated with XRD, Raman spectroscopy, BET, SEM, TEM, and HRTEM.
Here we will provide a brief description of the synthesis, fabrication and testing procedure of the NO2 sensor. The microstructure of the tungsten oxide films, and the effect of the film structure, grain size, and the sensor response to the ppm level concentration of NO2 will be described. The sensing mechanism with emphasis to adsorption and desorption will be explained in details.
Development and Applications of Carbon-Based Solid-State Potentiometric Sensors
Authors: Ummadi J Ganesh , Joshi Vrushali S , Koley Dipankar 
Published: February 2020

The solid-state ion-selective electrode (ISE) has been widely used in various applications due to its inherent properties of fast response time and ease of miniaturization. We have developed a new type of solid-state carbon-based ion-selective membrane to detect and quantify monovalent and divalent ions such as H+, Ca2+. Multiwalled Carbon nanotubes (MCNTs) have been used as carbon source in these carbon-based potentiometric sensors. The sensors were also miniaturized in the size of 25 to 40-micron diameter (μ-ISE). The Ca2+-μ-ISE showed fast response time (~1 sec or less), low limit of detection (~1 μM) and broad linear range (5 μM to 200 mM). In addition, the Ca2+-μ-ISE was proven to be insensitive towards redox molecules while demonstrating excellent selectivity towards major interfering ions (such as Na+, K+, and Mg2+, with logKCa
2+
,A = -5.5 to -6.0). The sensors were later used as a probe in Scanning Electrochemical Microscopy (SECM) to characterize Ca2+-releasing bioactive glass as well as monitoring real-time bacterial metabolic exchange in quorum sensing pathways. The recent development of this carbon-based miniaturized potentiometric sensors (Ca2+ and H+) and their application in live bacterial or biological systems would be presented at the meeting.
Using Physics-Based Models and Redox Shuttles to Investigate the Effects of FEC on Electrode Passivation
Authors: Jaini Rajiv , Fuller Thomas F 
Published: February 2020

Chemical additives, such as fluoroethylene carbonate (FEC), can be used to improve lithium-ion battery performance by facilitating the formation of a passivation layer on the negative electrode surface. We compare passivation layers formed by electrolytes with and without FEC, using the ferrocenium-ferrocene redox couple. To quantify experimental findings, we develop a mathematical planar-electrode impedance model to extract physical parameters related to the passivation layer.
Experimental cyclic voltammetry (CV) shows that the electronic passivity of the formed passivation layers is dependent upon the imposed electrochemical conditions. That is, potentiostatic holds cause surface passivation, leading to slower ferrocenium reduction kinetics. With increasing formation time, the high-frequency arc width of the impedance spectra increases for both electrolytes. However, the increase in high-frequency arc width is greater for electrolyte without FEC than that containing FEC. Formation potential influences the magnitude of electronic passivity of the solid electrolyte interphase (SEI), with more negative potentials increasing electronic passivity.
In Figure 1(a), the electrode surfaces have been passivated for 30 minutes under a 0.6 V potentiostatic hold. Two CVs are measured at ν = 10 mV s-1, comparing electrolytes with and without FEC. The addition of FEC to the primary electrolyte enhances ferrocenium reduction kinetics, when comparing peak heights and position. Figure 1(b) shows experimental and simulated impedance responses, obtained after 30 minutes of passivation around the redox shuttle equilibrium potential (3.24 V). Experimental and simulated impedance responses show good agreement over the frequency range shown, suggesting that reliable conclusions can be drawn about the SEI. Particularly, impedance response simulations suggest that interfacial kinetics and porosity of the outer layer of the SEI greatly influences the high-frequency arc width.

Figure 1
(Invited) Phase-Field Method of Li Dendrite Formation during Electrodeposition
Authors: Chen Lei , Liu Zhe , Qi Yue , Lu Peng , Chen Long-Qing 
Published: February 2020

The recent attempts to model the Li-dendrite formation using the phase-field method will be briefly reviewed. In particular, a nonlinear phase-field model, accounting for the Butler-Volmer electrochemical reaction kinetics, will be presented. The dendritic patterns are examined as a function of applied voltage and initial electrode surface morphology. A design map is proposed to tailor the electrode surface morphology and the applied voltage to avoid undesired dendritic patterns. The possibility of incorporating the effect of SEI on the Li-dendrite formation in a phase-field model will be discussed.
The State of Charge of Electrodes and Its Effects on Lithium-Iron-Phosphate Battery Simulation
Authors: Huang Hsuan-Han , Chung Wei-Lun , Liao Kuo-Chi , Lee Ching-Fei , Tien Jhen-Yang , Chen Hsun-Yi 
Published: February 2020

A lithium-iron-phosphate (LFP) battery is one of the ideal energy storage devices owing to its outstanding characteristics such as high power output, no memory effect, and slow degradation. While electrochemical models have been widely used to simulate the LFP battery behaviors, we found the accuracy of simulated LFP battery characteristics, including the cell voltage, lithium concentration distribution, and cell capacity, are highly related to the initial concentrations, namely, the state of charge (SOC) of each individual electrodes.
The amount of active lithium in an LFP battery, which determines the cell capacity, is a result of the SOCs of the anode and the cathode at the beginning of charge or the end of discharge processes. The SOC also dictates the equilibrium potential of individual electrodes, which in turn contributes to the full cell potential. However, it is difficult to estimate the amount of lithium in each individual electrode after the activation cycles because a certain amount of lithium is consumed to form the solid electrolyte interface (SEI) layer. Incorporation of inaccurate SOCs in models could lead to erroneous cell potential and capacity estimation. In this study, the initial concentrations of the anode and the cathode are estimated from the experimentally measured equilibrium potentials. By evaluating the characteristic points of individual electrodes and the corresponding reference points of a full cell, on the basis of low-rate discharge potential curves, the SOC of each individual electrode can be accurately calculated.
In order to evaluate the discharge performance of the LFP battery and gain insight into the effects of electrode SOCs, an electrochemical model based on coupled mass balance, charge balance, and reaction kinetics constitution laws is developed. To determine the initial SOCs of individual electrodes of the LFP battery, equilibrium potentials are experimentally measured by low-rate discharge while the characteristic points are calculated by identifying critical points of the discharge curves. The LFP battery model with such formally determined SOCs is validated by comparing the simulated discharge curves with experimental measurements under various loading demands, up to 2C. The simulated voltage plateau is closely matching the corresponding experimental results for a range of SOCs as shown in Figure 1. Overestimated cell voltage near the earlier stage of discharge and underestimated cell capacity at all C rates are observed in our simulation results, which could be improved by precise measurements of equilibrium potentials of the electrodes and the full cell. Further understanding of the effects of lithium loss during activation process with experiments and model simulation can assist the LFP battery design and optimize fabrication.

Figure 1
Deformation of Lithium Ion Battery Under Mechanical Loading
Authors: Kumar Abhishek , Allu Srikanth , Kalnaus Sergiy , Lebrun-Grandie Damien , Simunovic Srdjan , Turner John A , Wang Hsin 
Published: February 2020

We report on an experimental and numerical study of deformation in cell/string/module of a lithium ion battery under mechanical loading. We performed compression tests on individual components of the battery cell, such as anode, cathode and separator, and used the results to calibrate the specific material models for these components. Indentations tests were performed on individual battery cells and on a stack of 3 cells. During the indentation test, load, voltage and temperature of the cell were measured. We also studied the evolution of deformation in various components of the cell in order to understand the mechanisms of failure in separator, which could result in an electrical short and thermal runaway of the battery.
A finite element model (FEM) in which several layers are fully resolved and the remaining components are homogenized was developed for different cell combinations. In FEM maximum strain criterion in separator was used for element deletion and failure at short circuit.. We demonstrate the advantages of this approach by comparing the load-displacement curve and the nature of deformation obtained from simulations to those obtained from experiments.
Control and State of Charge Estimation of Lithium-Ion Battery Stacks
Authors: Pathak Manan , Sonawane Dayaram , Subramanian Venkat R. 
Published: February 2020

There is no way to directly measure the state of charge (SOC) for a Lithium-ion battery. Various methods for estimating the state of charge have been proposed like extended Kalman filtering, coulomb counting and impedance spectroscopy but these are not entirely reliable [1, 2]. The models need to be recalibrated after a few cycles in order for accurately predicting the state of charge.
The prediction of SOC of individual cells is even more important for a stack of cells in order to efficiently use the stack. Differences in the SOC of individual cells in a stack could lead to the cells being charged/discharged to different potentials, which could affect the safety of the stack or could damage the cells [2, 3, 4]. Cell balancing therefore is an important functionality of any Battery Management System (BMS) which necessitates the accurate estimation of SOC.
In this paper, we present the estimation of SOC of individual batteries in a stack using a physics based reformulated model [4], with the use of the voltage-time data while charging the cells. This kind of model adds more fidelity to the SOC estimation as the battery undergoes degradation after many cycles. Further, optimal charging profiles for the battery stacks could be suggested that would maximize the amount of charge stored while keeping the battery safe. Reformulated models enable efficient simulation and control for online control applications.
Acknowledgements

The work presented herein was funded in part by the Clean Energy Institute at the University of Washington, Seattle and the Advanced Research Projects Agency – Energy (ARPA-E), U.S. Department of Energy, under the Award Number DE-AR0000275.

References

V. Pop, H.J. Bergveld, J.H.G. Op het Veld, P.P.L. Regtien, D. Danilov, and P.H.L. Notten, J. Electrochem. Soc., 153 (11), A2013-A2022, 2006.

W.B. Gu and C.Y. Wang, J. Electrochem. Soc., 147(8), 2910–2922, 2000.

A. Szumanowski and Y. Chang, IEEE Trans. on Vehic. Tech., 57(3), 1425-1432, 2008.

P. W. C. Northrop, V. Ramadesigan, S. De, and V. R. Subramanian, J. Electrochem. Soc., 158(12), A1461-A1477, 2011.

F. Zhang, G. Liu and L. Fang, Advanced Intelligent Mechatronics, AIM, IEEE/ASME International Conference on , 1008-1013, 2008.

J. Newman, Electrochemical Systems, 2nd ed. Prentice Hall, 1991.

V. Ramadesigan, K. Chen, N.A. Burns, V. Boovaragavan, R. D. Braatz, and V. R. Subramanian, J. Electrochem. Soc., 158(9), A1048-A1054, 2011.
Development of a Genosensor for Sickle Cell Anemia Trait Determination
Authors: Janegitz Bruno Campos , Brazaca Laís Canniatti , Bramorski Camila Barbosa , Cancino-Bernardi Juliana , Zucolotto Valtencir 
Published: February 2020

Sickle cell anemia (SCA) is a common recessive genetic condition in which patients produce hemoglobin S (HbS), an abnormal form of the protein, instead of hemoglobin A, the regular form. SCA is caused by the substitution of a single nitrogenous base adenine for thymine (GAG-> GTG), encoding valine instead of glutamine.1 Deoxygenation of HbS leads to its polymerization, damaging the cell membrane and reducing the lifetime of erythrocytes dramatically – which, in turn, leads to anemia. In some regions of Africa, up to 40% of the population possess its genetic trait, being considered a public health serious problem2. As the disease is possibly deadly, presents very low cure chances and has limited treatment, carriers determination is a key feature to assist in reproducibility decisions. Currently, trait determination is mainly performed by liquid chromatography, electrophoresis and polymerase chain reaction (PCR)3,4. These techniques are not widely used due to its complexity, lack of portability, high price and specialized personal and equipment demand. In this study we have developed an electrochemical genosensor for simple, low cost and rapid SCA carriers determination. Single DNA strands corresponding to the sequence of a SCA carrier were immobilized in gold platforms using the self-assembled-monolayers technique. The determination of SCA trait is then performed by analyzing the film’s charge transfer resistance using Electrochemical Impedance Spectroscopy. The genosensor was able to distinguish between healthy and unhealthy subjects with great precision besides displaying a wide linear range (0.01 to 7.5 µmol/L, R2 = 0.927). Furthermore, the device presented a detection limit of 7.0 nmol/L. We expect that such devices increases the number of SCA carriers determination, promoting early diagnosis and genetical counseling.

References:

1 Barany, F. Genetic-Disease Detection and DNA Amplification Using Cloned Thermostable Ligase. Proceedings of the National Academy of Sciences of the United States of America
88, 189-193, doi:10.1073/pnas.88.1.189 (1991).
2 Diallo, D. & Tchernia, G. Sickle cell disease in Africa. Current Opinion in Hematology
9, 111-116, doi:10.1097/00062752-200203000-00005 (2002).
3 Ayatollahi, M. & Haghshenas, M. Application of the polymerase chain reaction to the diagnosis of sickle cell disease in Iran. Archive of Iranian Medicine
7, 84-88 (2004).
4 Bender, M. A. & Seibel, G. D. Sickle Cell Disease. (University of Washington, 2003).
Tetracyanoborate Anion Based Phosphonium Ionic Liquids As Electrolytes for Pyrrole Electropolymerization
Authors: Nishihata Keiichi , Tsunashima Katsuhiko , Matsumiya Masahiko , Ono Yasushi 
Published: February 2020

Room-temperature ionic liquids (RTILs) have been regarded as potential electrolytic media for electropolymerization processes.1 Many kinds of RTILs have been investigated for the electropolymerizations; however, RTILs based on tetracyanoborate (B(CN)4
-, TCB) anion have been rarely employed. On the other hand, we have designed quaternary phosphonium RTILs exhibiting high transport property and high stability.2 In this work, we report the physicochemical and electrochemical characterization of the phosphonium RTILs based on the TCB anion (Fig. 1) as electrolytes for electropolymerization of pyrrole (Py).
The preparation of the TCB-based phosphonium RTILs was performed by aqueous ion exchange reaction of the precursor quaternary phosphonium halides with sodium tetracyanoborate (Na-TCB). Residual metal and halide ions in the clude RTILs were removed by a silica gel column. The combination of the asymmetric phosphonium cations with TCB anion successfully gave liquids at ambient temperature. The TCB-based phosphonium RTILs showed thermal decomposition temperatures at more than approximately 400°C.
The electropolymerization of Py in the TCB-based phosphonium RTILs was carried out by cyclic voltammetry (CV) method. Fig. 2 showed the cyclic voltammograms for the electropolymerization of Py in P2225-TCB. It was found that an irreversible oxidation peak was observed and maintained when the cycle was repeated, giving the PPy films on the electrode surface. As shown in Fig. 3, the SEM images of the PPy films exhibited the relatively uniform surface when compared to the PPy films grown in the corresponding bis(fluorosulfonyl)amide-based phosphonium RTILs. The thermal stability of the PPy film grown in the TCB-based phosphonium RTILs will be also discussed.
References
1 K. Sekiguchi, et al, J. Electroanal. Chem.
,
557, 1 (2003).
2 K. Tsunashima, et al, Electrochem. Commun., 9, 2353 (2007).

Figure 1