bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tuning the Selectivity of CO2 Electrochemical Reduction Toward Hydrocarbon with Ligand Modified Metal Electrocatalyst
Authors: Fang Yuxin , Cheng Xun , Xu Ye , Flake John 
Published: February 2020

Reduction of CO2 has become an attractive process to form fuels from renewable energy sources. Multiple approaches (electrochemical, photochemical, homogeneous catalysis, etc.) have been made to optimize this artificial photosynthesis. The electrochemical approach has the benefit from using low-cost electrical energy (wind or solar) and producing renewable hydrocarbon fuels. Various metals and their alloys (Au, Ag, Cu, Pd and Pt etc.) have been studied exhaustively on their catalytic ability in CO2 electrochemical reduction.(1) With the calculation basis in the scaling relationship by Nørskov et al., nanoscale cathode catalysts are continuously being explored results in achievement in highly selective production of CO, formate and methane, etc. (2-4) The challenge to develop the optimal catalyst lies in the selectivity toward the desired product in which liquid form product is favored due to transportation consideration.
Inspired by the nature’s enzyme catalyzing photosynthesis that yields outstanding selectivity, we consider the ligand’s effect on the selectivity. Gold has been known to catalyze the CO2 reduction to produce CO with trace amount of formate. In present work, we demonstrate the ability in tuning the selectivity of this reaction by control the surface pKa with different organic thiol self-assembled monolayer. As shown in figure 1, the selectivity of CO and formate have been alternated at the present of 4-mercaptanethylpyridium on gold foil thus the product was switched from gas phase toward liquid phase. Surface chemistry has been shown to hold promising role in designing catalyst selectively.
REFERENCE
1. Y. Hori, in Modern Aspects of Electrochemistry, C. Vayenas, R. White and M. Gamboa-Aldeco Editors, p. 89, Springer New York (2008).
2. C. Shi, H. A. Hansen, A. C. Lausche and J. K. Norskov, Physical Chemistry Chemical Physics, 16, 4720 (2014).
3. D. R. Kauffman, D. Alfonso, C. Matranga, H. Qian and R. Jin, Journal of the American Chemical Society, 134, 10237 (2012).
4. K. Manthiram, B. J. Beberwyck and A. P. Alivisatos, Journal of the American Chemical Society, 136, 13319 (2014).

Figure 1
An Investigation into the Electrocatalytic Activity of Nitrogen Doped Metalated Carbons
Authors: Donne Scott W , Kwong Laurence 
Published: February 2020

Energy is a globally important commodity, used from powering our homes and appliances to helping produce goods that improve society’s quality of life. The majority of the world’s energy requirements are currently provided by fossil fuel sources such as coal, oil, and natural gas. The extended use of these fuels in the past has contributed to significant climate change which is adversely affecting our environment and is unsustainable in the long term. Clean and renewable sources such as solar power and wind power have emerged as technologies that can produce energy with zero emissions. One of the most significant issues preventing the widespread adoption of these renewable technologies is their intermittent output which is affected by variations in the wind load or incident radiation. This prevents these technologies from providing reliable base load power, especially during peak periods at night time. A solution to this is the use of hydrogen for energy storage which is produced using renewable energy.
One of the most promising technologies for the efficient, large scale production of hydrogen from water is the hybrid sulphur cycle. This cycle utilises cheap and abundant sulphur dioxide as a chemical depolariser, reducing the potential required to produce hydrogen from water compared to conventional electrolysis. In this process, sulphur dioxide is oxidised at the anode of an electrolyser, producing sulphuric acid and hydrogen ions which are subsequently reduced at the cathode to produce hydrogen gas. The sulphuric acid is then thermally decomposed to produce water, oxygen, and regenerate the sulphur dioxide for recycling. One of the inhibitors to this technology is the requirement of expensive noble metal catalysts such as palladium and platinum for the oxidation reaction, and so one of the challenges of the scientific community is to identify suitable low cost alternatives.
Much work has demonstrated the improvement in the catalytic activity of carbon electrodes through the process of nitrogen doping. This work will examine the effect of nitrogen doping on the catalytic activity of nitrogen doped metalated carbons in the hope to identify suitably active alternatives to the noble metals or at the very least, reduce the quantities required.
CO2 Electro-Reduction on Bio-Inspired Iron Sulfide Under Mild Conditions
Authors: Roldan Alberto , de Leeuw Nora 
Published: February 2020

In recent years, carbon dioxide capture and utilisation is gaining attention driven not only by environmental factors but also by the potential to use it as chemical feedstock. One plausible utilisation route is its conversion to form small organic molecules, yet CO2 is thermodynamically very stable and its reduction is energy intensive. Nevertheless, the CO2 conversion takes place under mild conditions in chemoautotrophic bacteria catalysed by enzymes.1 These enzymes often contain Fe4S4 clusters, which have been shown to act as electron-transfer sites 2, 3 but they can also be catalytically active centres for molecule transformations.4 An iron thio-spinel mineral is structurally similar to this cluster,5 fact that brings us to suggest it as a novel heterogeneous catalyst. We present a theoretical investigation using the iron sulfide greigite mineral (Fe3S4) as a catalyst to transform CO2 into small organic molecules, such as formic acid, methanol and acetic acid. In agreement with the experiments, the adsorbed species and the products formed depends on the solution pH. The reduction consists of a sequential hydrogenation steps that we have studied by either the common Langmuir-Hinshelwood or the Eley-Rideal mechanisms. We have identified more than 170 intermediates describing the different reaction pathways where the most favourable ones lead to formate and carboxyl as key intermediates in the reduction process. The selectivity is controlled by different sites on the surface sites yielding mainly HCOOH and CH3OH. However, some surface species interact among them to generate molecules with higher carbon content.

References

[1] C. Huber and G. Wachtershauser, Science, 276 (1997) 245
[2] Y. Nicolet, P. Amara, J. M. Mouesca and J. C. Fontecilla-Camps, Proc. Natl. Acad. Sci. U. S. A. 106 (2009) 14867
[3] T. Hayashi and A. Stuchebrukhov, Abstr. Pap. Am. Chem. Soc.243 (2012)
[4] H. Seino and M. Hidai, Chemical Science 2 (2011) 847.
[5] W. Martin and M. J. Russell, Phil. Trans. Royal Society 358 (2003) 59

Figure 1
Direct Charge and Discharge Using the Glycolic Acid/Oxalic Acid Redox Couple for the Carbon-Neutral Energy Circulation
Authors: Yamauchi Miho , Hata Shinichi , Kitano Syo , Sadakiyo Masaaki , Takeguchi Tatsuya 
Published: February 2020

The major impact of increasing CO2 concentration on climate change has been recognised. Thus, efficient utilisation of renewable electricity is of increasing significant importance and development of various manner of its operation is required for our energetic and environmental sustainability. Recently, electric power storage in high-energy chemicals, called “energy carriers”, has received much attention for the efficient storage and on-demand supply of renewable electricity. Here, we demonstrate direct power charge using an alcohol/carboxylic acid redox couple. Highly transportable glycolic acid, an alcoholic compound, was successfully produced by electroreduction of oxalic acid, a dicarboxylic acid, on ubiquitous TiO2 catalysts with high efficiency and selectivity (70-95% Faradaic efficiency and >98% selectivity) under mild conditions in the potential region of -0.5 to -0.7 V vs. the RHE at 50 ºC. The most desirable characteristic of this electroreduction is the suppression of hydrogen evolution even in acidic aqueous media (Faradaic efficiency of 70–95%, pH 2.1). The detailed observation of TiO2 catalysts using scanning TEM and eels techniques provided a mechanistic insight into the highly selective catalysis. Recently, we coud demonstrate glycolic acid synthesis using an electrochemical cell consisting of the TiO2catalyst and a polymer electrolyte, i.e., a polymer electrolyte alcohol synthesis cell.
Furthermore, we succeeded in electric power generation via the selective electrooxidation of glycolic acid to oxalic acid without CO2emission—specifically, carbon-neutral power generation. These results are the first experimental proof of concept for a carbon-neutral energy circulation system based on charging/discharging electric power using an alcohol/carboxylic acid redox couple[1, 2] as shown in Fig. 1.
Reference
[1] R. Watanabe, M. Yamauchi, M. Sadakiyo, R. Abe, T. Takeguchi, “CO2-free electric power circulation via direct charge and discharge using the glycolic acid/oxalic acid redox couple",
Energy Environ. Sci.
, 8, 1456-1462 (2015).
[2] T. Matsumoto, M. Sadakiyo, M.L.Ooi, S.Kitano, T.Yamamoto, S.Matsumura, K. Kato, T. Takeguchi, and M. Yamauchi, “CO2-Free Power Generation on an Iron Group Nanoalloy Catalyst via Selective Oxidation of Ethylene Glycol to Oxalic Acid in Alkaline Media” ,
Sci. Rep.
, 4,5620(2014).

Figure 1
X-Ray Diffraction and in-Situ Synchrotron Studies on Phase Evolution in Pr2NiO4: Understanding the Local Structure Changes
Authors: Dogdibegovic Emir , Wright Christopher J. , Zhou Xiao-Dong 
Published: February 2020

Solid oxide fuel cells produce electricity from the electrochemical oxidation of a wide variety of fuels. Recently, a layered-oxide cathode material, Pr2NiO4, has captured the field’s interest. Pr2NiO4 is performance stable and shows higher power densities than commonly used cathodes. However, it partially decomposes under operating conditions, which has little impact on the cell performance. Preliminary thermal stability results show that after only 50h at 790 °C the parent phase undergoes substantial decomposition, which is evident by evolution of PrOx and other layered phases. However, industrial applications require minimal phase changes over long term operation, due to possible structural collapse, requiring stabilization of Pr2NiO4. The active phase(s) are unknown in operating cells, as is the reason why the phase change has little effect on the performance. In this work in-situ x-ray total scattering atomic pair distribution function (PDF), and x-ray powder diffraction (XRD) analyses were used in an attempt to track phase evolution in Pr2NiO4 during thermal annealing and electrochemical operation. The study focuses on the role of PrOx and other layered byproducts on cell stability and performance. PDF and XRD were used to solve the changing Pr2NiO4 atomic structure via Monte Carlo simulations. This work presents an attempt to obtain fundamental knowledge of the local structure changes occurring in Pr2NiO4 and its byproducts, which in turn could provide a better understanding on the phase stabilizing mechanism.
The authors would like to thank the Department of Energy for their support of this project under contract #DE-FE0023475. The use of the Advanced Photon Source was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
In Situ Optical Studies of CO2 and Co-Electrolysis
Authors: Qadri Syed Noorullah , Kirtley John D. , Steinhurst Daniel A , Balow Robert Benjamin , Pehrsson Pehr E. , Owrutsky Jeffrey C 
Published: February 2020

The ability to understand the underlying mechanisms for electrolysis of CO2 and co-electrolysis of CO2 and steam has been hindered due to a lack of experimental methods that can probe intermediate species and materials directly during operation. Although there have been studies on using Ni-YSZ and ceria based cathodes for electrode materials in high temperature solid oxide electrolysis cells (SOECs), these have mainly utilized post-mortem and in situ electrochemical analyses. Here, we demonstrate an in situ duplex technique that combines near infrared thermal imaging (NIRTI) and Fourier-transform infrared emission spectroscopy (FTIRES) to monitor processes for electrolysis of CO2 and co-electrolysis on operating SOECs. The results are correlated with traditional electrochemical measurements to identify any polarization dependence on species during the course of reactions under a range of conditions.
CO2 and co-electrolysis conditions are investigated on anode- and electrolyte-supported cells between 700 and 900 °C. NIRTI results indicate cooling on the anode surface during endothermic processes and heating during high loads due to joule heating. FTIRES indicates the first observation of a carbonate intermediate formed on a cathode during operation at normal SOEC working pressure and temperature. Diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) is used to confirm band assignments seen in situ for electrode materials. Ex situ mass spectrometry and exhaust gas FTIR absorption measurements are combined with in situ results to further characterize and quantify carbon monoxide and syn-gas production. These studies serve as benchmark data for better understanding the processes during CO2 electrolysis in real working conditions.
Fouling Behavior of Multivalent Cations to Cation Exchange Membranes in Reverse Electrodialysis
Authors: Kim Da-Eun , Oh Yoontaek , Choi Jang-Uk , Song Chan-Ho , Chae Soryong , Kim Chan-Soo , Jeong Nam-Jo , Kang Moon-Sung , Park Jin-Soo 
Published: February 2020

Reverse electrodialysis (RED) represents an energy conversion technology from the salinity difference of concentrated salt solutions (e.g., sea water) and diluted salt solutions (e.g., river water). The RED stack is comprised of an alternating arrangement of cation- and anion-exchange membranes between two electrodes that selectively transfer anions and cations. However, the sea water used for the RED may contain the divalent cations (i.e., Ca2+ and Mg2+). Thus, electrostatic characteristics of divalent cations may lead to membrane surface fouling. The membrane fouling cause increase electrical resistance and the increase of maintenance cost, and a significant decrease in operating performance. In this study, the influence of membrane fouling in RED by divalent cations such as Ca2+ and Mg2+ was investigated experimentally, and equilibrium tests, open circuit voltage, stack resistance, and power density were measured at different operation conditions. Commercially available cation exchange membranes were used. As a result, the divalent ions behaved a reversible foulant to cation exchange membranes caused an increase in resistance. Calcium ion exchanged cation exchange membranes showed higher resistance than magnesium ion exchanged ones. It is also concluded that the number of hydration attached to cations greatly influenced resistance.
Acknowledgements
This work was supported by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, and Republic of Korea (No. 20143030071240).
(Invited) Printable Paper-Based Wearable Diaper-Type and Adhesive Bandage-Type Biofuel Cells for Urine Sugar and Sweat Lactate Monitoring
Authors: Shitanda Isao 
Published: February 2020

Printable Electrochemistry has attracted attention for the development field of a disposable biosensor and biofuel cell. A printable paper-based biofuel cell (PBFC) is useful for energy harvesting power sources in the Internet of Things (IoT) field [1-3]. In addition, PBFC is suitable for an application as a self-powered wearable sensor. In the present study, I introduce two paper-based wearable biofuel cells fabricated by screen-printing technique (Fig. 1). One is used as a self-powered diaper sensor (right side in Fig. 1). The biofuel cell can generate electric power from glucose in urine. The maximum output power increase along with increase of glucose concentration. Thus, we can monitor the glucose concentration by measuring the maximum output power. The paper-based biofuel cell exhibited a maximum power density of 0.7 mW in 100 mM glucose solution. Our group also developed an adhesive bandage-type biofuel cell, which get a power from lactate in sweat (left side in Fig. 1). In the present study, we discuss the characteristics of the wearable biofuel cells in detail.
Acknowledgement
This work was supported by JST-ASTEP Grant Number AS272S004a.
References
[1] I. Shitanda, S. Kato, Y. Hoshi, M. Itagaki, S. Tsujimura, Chem. Commun. 49 (2013) 11110.
[2] Claudia W. Narváez Villarrubia et al., Electrochem. Commun, 45 (2014) 44.
[3] Carolin Lau et al., Int. J. Hydrogen. Energy, 42 (2015) 14661.

Figure 1
Electrochemistry Based Platform for the Highly Sensitive Detection of Human Parathyroid Hormone Using Au Electrode with MoS2/Graphene Matrix
Authors: Lee Min-Ho , Kim Hye Youn , Lee Kook-Nyung , Seo Youngtai 
Published: February 2020

A self-assembled novel nanocomposite composed of MoS2-Graphene(MoS2-Gr) composites were electrostatically formed on top of gold (Au) electrode and their biochemical amplification responses were reported. The properties of the MoS2-Gr were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Fourier transform infrared spectrometer (FT-IR). Cyclic voltammetry was performed in the presence of Parathyroid Hormone (PTH) and its linearity was obtained by measuring the anodic current signals coming from interactions between MoS2-Gr-Ab and different concentrations of PTH with the aid of substrate and enzyme conjugated secondary antibodies. With this complex and Au as working electrode, we have developed a portable biosensing platform which shows good sensitivity in detecting PTH as low as 10 pg/mL and high reproducibility
Elasticity Measurement of High-Metastatic Breast Cancer Cells That Highly Express Intermediate Filament Protein Nestin
Authors: Yamagishi Ayana , Takano Yuta , Mishima Mari , Imaizumi Miku , Okada Tomoko , Nakamura Chikashi 
Published: February 2020

Nestin is an intermediate filament protein that is used for a neural stem cell marker. Since its high expression was reported in several high-metastatic cancer cells, nestin is considered to be involved in metastasis of cancer cells1. However, relationship between nestin and metastatic mechanism of cancer cells is unknown. Cancer cells are generally softer than benign cells2. Because intermediate filaments contribute to cell mechanical property by binding with other cytoskeletal proteins, nestin expression could affect elastic modulus of cancer cell. Previously, we have obtained a highly metastatic murine breast cancer cell line, SC2 which expressed three-fold nestin of parent strain. In this study, we established nestin-knockout SC2 cell by CRISPR/Cas9-mediated genome editing to evaluate an effect of nestin disruption on the cell.
Intermediate filaments are composed by three domains and rod domain in the N-terminus is necessary to form bundles. In order to disrupt nestin gene, sgRNA was designed to target the rod domain of mouse nestin. Plasmid expressing the sgRNA and Cas9 was transfected into the SC2 cells by lipofection. After transfection, the cells were cultured in RPMI 1640 medium including G418 (500 μg/mL) for 10 days. Obtained clones were confirmed by immunostaining and three clones were found to be disrupted nestin. Analysis of genome sequence revealed that frameshift mutation was occurred by deletion of nucleotides in nestin gene of the obtained clones. These results indicated that nestin knockout succeeded by CRISPR/Cas9-mediated genome editing.
To examine in vivo metastatic activity of nestin knockout cells, the SC2 and knockout cells were intravenously injected into mice. Survival time of mice injected with nestin-knockout cell was significantly prolonged, suggesting that nestin knockout reduced metastatic ability of the SC2 cells. We measured elastic modulus of cell body by using of atomic force microscopy (AFM) and cylindrical-shaped AFM probe with 2.2 μm in diameter. Force curve obtained when the probe was contacted with cell surface was fitted by Herz model and young’s modulus was calculated. Since the young’s modulus of the nestin-knockout cell was significantly higher than that of the SC2, nestin knockout caused increase in mechanical property. In the metastasis process, cancer cells invade surrounding tissue. Thus, expression of nestin reduces the elastic modulus in the cell body and leads high metastatic activity.
(1) Kleeberger, W. et al. Cancer research 67, 9199-9206, 2007.
(2) Cross, E. S. et sl. Nature nanotechnology 2, 780-783, 2007.
(Invited) Diamond Electrodes for Sensitive Electrochemical Detection
Authors: Kondo T. 
Published: February 2020

Boron-doped diamond (BDD) electrodes are known to have excellent electrochemical properties, such as wide potential window and low background current, as well as extreme physical/chemical stability. Based on these properties, the BDD electrodes are expected to be used for sensitive electrochemical detection in various research fields including bioelectrochemistry. Usually, BDD electrodes are prepared by deposition of a polycrystalline BDD thin film on a conductive silicon wafer substrate, and thus obtained as an inflexible macro-electrode. In order to expand application fields of BDD electrodes for sensitive electrochemical detection, we have developed screen-printed BDD electrodes and BDD microring electrodes.
1. Screen-printed BDD electrodes
Screen-printed BDD electrodes were developed as a low-cost, light-weight, flexible, disposable and sensitive electrochemical electrode. An ink containing BDD powder (BDDP, particle size < 1 μm) and polyester (PES) resin binder was prepared and was subjected to screen printing to obtain a polyimide film-based screen-printed BDD electrode. In comparison with conventional carbon-printed electrode, the BDDP-printed electrode was found to show low background current, leading to large signal-to-background (S/B) ratio. Electrochemical properties of the BDDP-printed electrode was changed drastically by the PES/BDDP ratio of the ink. The BDDP-printed electrode showed planar electrode-type behavior at small PES/BDDP ratios. At a BDDP-printed electrode with large PES/BDDP ratios, however, microelectrode-type voltammetric behavior was observed due to the random microelectrode array effect. The S/B ratio for the voltammetric detection of ascorbic acid was found to be in the order BDDP-printed electrode (PES/BDDP = 1.0) > BDDP-printed electrode (PES/BDDP = 0.3) > conventional polycrystalline BDD electrode.
2. BDD microring electrodes
BDD microring electrodes were developed for electrochemical detection at a micrometer-scale local space. A quartz glass rod was pulled to prepare a quartz glass needle with a tip diameter of ca. 200 nm. BDD thin film was deposited on the needle tip to obtain BDD microelectrode. After deposition of an insulating layer on the electrode surface, the tip was cut by focused ion beam to obtain microring electrode. Diameter of the BDD microring electrode was ca. 5 μm. Oxygen reduction reaction current at a platinum microelectrode in the presence of bovine serum albumin (BSA) was found to be reduced by 58% from the current in the absence of BSA. In contrast, the current reduction was found to be 20% at the BDD microring electrode, showing good durability to electrode fouling by the presence of BSA.