bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Electric-Field Driven Selective Electrocatalytic CO2 Conversion
Authors: Kwon Youngkook 
Published: December 2020

The efficient electrochemical conversion of CO2 to fuels or stock chemicals with high-energy density would be a major step forward in the introduction of a carbon neutral energy cycle. Especially, understanding the role of electrocatalysts, supports, and electrolytes that can efficiently reduce CO2 to fuels with high selectivity is a subject of significant interest.
One of the achievements in electrochemical CO2 reduction is the clarification of the catalysts toward two-electron involved products such as CO and formate. For instance, CO is selectively generated on Au, Ag, and single-atom catalysts and formate has been selective on Hg, Pb, Sn or alloy catalysts. Interestingly, from our recent work, CO/formate ratio can be selectively controlled on formate selective catalyst by tuning the interfacial electric field.[1] On copper catalyst, the selection of alkali cations has direct influence on activity and product selectivity; increasing the size of mono-valent cations can increase the activity and selectivity toward C-C coupled products by modulating the interaction energy between adsorbates and electric fields at the interface.[2] In addition, copper catalyst with a specific atomic-scale gap accelerates the reaction kinetics and selectivity to C2+ products.[3] Therefore, understanding the roles of catalyst, support and electrolyte offers the design of efficient, yet cheap electrochemical CO2 reduction systems.
[1] Y. Kwon et al., ACS Sustain. Chem. Eng.
2020, 8, 2117.
[2] Y. Kwon et al., J. Am. Chem. Soc.
2016, 138, 13006.
[3] Y. Kwon et al., Adv. Energy Mater.
2020, 1903423.
Virtual Analysis of Gas-Diffusion-Electrode CO2 Electrolyzers
Authors: Weng Lien-Chun , Bui Justin C. , Romiluyi Oyinkansola , Bell Alexis T. , Weber Adam Z. 
Published: December 2020

The electrochemical reduction of CO2 (CO2R) to value-added products is an attractive technology for tackling the rising atmospheric CO2 levels and storing intermittent renewable energy into chemical bonds. Fundamental understanding of CO2R has progressed significantly in recent years and is critical in the development of CO2R to liquid-fuel electrolyzers, where gas-diffusion electrodes (GDEs) have been shown to be key enabling architectures. Various designs have been proposed and studied in the literature to enhance overall selectivity, rates, and maximize the conversion of CO2, the latter of which is only now being recognized as a critical issue. In this respect, there is a need to explore the governing phenomena inherent in these architectures to enable optimization. Mathematical modeling is ideally suited to tackle and explore these multiphysics interactions and provide virtual design analysis.
In this talk, we discuss modeling methodologies and physics inherent in these devices and present our recent modeling of GDEs for CO2 reduction. We specifically examine the impacts of multiphase flow and related phenomena on overall cell performance. We then explore the performance and limitations of various cell designs guided by simulation results and examine potential methods for improving water management and tuning catalyst selectivity including the use of different anion-exchange and bipolar membranes. Finally, we discuss the disparities in local environments between aqueous and GDE devices and propose strategies to reduce the gap in knowledge between the two systems.
Acknowledgements
This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993.
Electrochemical Reduction of CO2 Using Carbon-Based Materials Modified with 3d-Metal Atoms As Electrocatalysts
Authors: Kamiya Kazuhide , Nakanishi Shuji 
Published: December 2020

For the reductive CO2 fixation using solar energy, photo-generated electrons and/or holes must be captured and utilized for chemical reactions that generate products beneficial to humans. To construct the artificial photosynthesis systems, electron transfer catalysts designed to promote electrochemical CO2 reduction reactions (CO2RR) are a critical requirement. Previous studies have shown that precise tuning of adsorption energies of key intermediates is critical for obtaining high activity and reaction selectivity. There are two important factors that determine the adsorption energy of the intermediate on electrocatalysts. First, the metal species in the catalyst, i.e., the transition metals at the active sites with a higher number of d-electrons, tend to reduce the adsorption energy. Previous works have investigated the effects of metal species on the CO2RR using organometallic complexes as platforms to support various metals via coordination bonds. For example, cobalt-modified tetraphenylporphyrin (TPP) is known to exhibit efficient CO2RR activity due to its proper binding strength to COOH*, whereas nickel (Ni) and copper (Cu) modified TPP are known to have low catalytic activity due to the low binding energy of COOH*. The second critical factor is the coordination structure of the metal. First-principles calculations have revealed that a decrease in the coordination number of Pt and Cu in the bulk increases the bond strength of CO* and affects the activity of the CO2RR. Thus, it can be expected that the coordination number can be a control parameter to improve the performance of metal species that were previously thought to have no CO2RR activity. We have investigated the effects of metal species and the coordination structure on CO2RR using graphene and covalent triazine frameworks (CTF)[1,2]. CTF consisting of microporous conjugated polymers with 1,3,5-triazine linker units, are suitable for investigating the above issue due to the high design flexibility. Through the studies, we have revealed that Ni-modified graphene and CTF can work as efficient electrocatalysts for CO2RR due to the unsaturation nature of the Ni atoms on the substrate. In this talk, we report our systematic studies on CO2RR using carbon-based materials with 3d metal atoms, focusing on the effects of metal species and coordination structures.
[1] P. Su, K. Iwase, S. Nakanishi, K. Hashimoto, K. Kamiya, Small, 12, 6083-6089 (2016).
[2] P. Su, K. Iwase, T. Harada, K. Kamiya, S. Nakanishi, Chem. Sci., 9, 3941-3947 (2018).

Figure 1
(Invited) The Electrochemical CO2 Reduction Reaction: Understanding the Selectivity of the Cu Catalyst
Authors: Bagger Alexander 
Published: December 2020

Electrochemical CO2 and CO reduction holds the promise to be a cornerstone for sustainable production of fuels and chemicals. However, it is a complex reaction which give multiple different products depending on metal catalyst [1]. The product distributions on the metals catalyst can be understood by ignoring the reaction pathways and grouping the multiple metal catalyst by their product selectivity [2]. It shows that, the unique copper catalyst, as the only metal catalyst has the ability to bind CO* while not having hydrogen under potential deposited (UPD), which results in a high value multiple-carbon product distribution. Furthermore, the exotic product distribution has been shown to be dependent on the exact crystal orientation of the Cu facets for the Cu catalyst [3,4]. Consequently, understanding and improving the product selectivity of the Cu catalyst is a complex property to understand.
In this talk I will discuss the properties of the Cu catalyst: (1) How is the products from the Cu catalyst facets related to each other and how they can be grouped. (2) How can descriptors and models be built to understand and guide the product distribution of the Cu catalyst toward selective high value products [5].
[1] Y. Hori et. al., Journal of the Chemical Society, Faraday Transactions, 1989, 85, 2309-2326.
[2] A. Bagger et. al., ChemPhysChem, 2017, 18, 3266–3273.
[3] Y. Hori et. al., Journal of Molecular Catalysis A: Chemical, 2003, 199, 39-47.
[4] K. J. P. Schouten et. al., Journal of the
American Chemical Society, 2012, 134, 9864-9867.
[5] A. Bagger et. al., ACS Catal.
2019, 9, 9, 7894–7899.
Hybrid Copper Macrocycle/Nickel-Nitrogen Doped Graphite for Aqueous Electrochemical Carbon Dioxide Reduction
Authors: Lee Jack , Asset Tristan , Atanassov Plamen , Minteer Shelley D. 
Published: December 2020

Increasing levels of carbon dioxide in the atmosphere has led to adverse effects on the environment due to climate change. These negative effects have stimulated efforts to develop ways to capture carbon dioxide. The issue is what to do with it when it is captured since its current uses are limited. Therefore, identifying catalysts that can reduce carbon dioxide into useful chemicals is a potential solution to this impending problem. Using electrocatalysis could be even more advantageous as it could allow for the use of renewable energy to directly fix carbon. Depending on the final use of the reduced products, whether as fuels or materials, the net effect on carbon dioxide in the atmosphere would be neutral or negative respectively.
Combining catalysts that can work together to help make carbon dioxide electrolysis products is the strategy employed in this work. A variety of metal/nitrogen-doped graphite electrocatalysts were screened for their activity for carbon dioxide reduction. These carbon-based metal/nitrogen catalysts primarily produce carbon monoxide from carbon dioxide. For this reason, several different metallized porphyrins and phthalocyanines were tested for their ability to reduce carbon monoxide, as they can be easily attached to the graphitic catalysts. Copper phthalocyanine has been shown to be an effective catalyst for both carbon monoxide and carbon dioxide reduction. Nickel/nitrogen doped graphite when used with copper phthalocyanines has shown promise as a way of increasing the relative amount of two carbon products. So far combining the two catalysts has been shown to increase the amount of ethylene relative to the amount of methane by a factor of six, compared to using the copper phthalocyanine by itself.
(Invited) New Ionic Liquids (ILs) for Secondary Batteries: Interplay between Structure, Electrical Response and Conductivity Mechanism
Authors: Vezzu Keti , Pagot Gioele , Negro Enrico , Di Noto Vito 
Published: December 2020

The main bottleneck towards the development of high-performing “beyond Lithium ion” batteries in the portable electronic, electric automotive, and stationary applications [1] is the lack of electrolytes that are safe, electrochemically stable, and compatible with the electrode materials [2-3].
Recently published papers demonstrated that halo-aluminate ionic liquids (ILs) can provide an appealing alternative to conventional ethereal solvent-based electrolytes due to their low volatility, negligible flammability, and excellent electrochemical performance [4-7].
Following this, an overview on recent advancements on electrolytes for secondary batteries is presented, with a particular reference to imidazolium- and pyrrolidinium-based ILs. Insights on the interplay between thermal properties, structure and conductivity of BF4
-, Cl-/AlCl3, Cl-/TiCl4, and I-/AlI3-based systems are given, thus providing an in-depth understanding of the relation existing between ion speciation, long-range charge transfer mechanism, conductivity mechanisms and electrochemical performance of this very promising class of materials.

References

[1] B. Dunn, H. Kamath, J. M. Tarascon, Science 334 (2011) 928-935.
[2] V. Di Noto, T. A. Zawodzinski, A. M. Herring, G. A. Giffin, E. Negro, S. Lavina, Int. J. Hydrogen Energy 37 (2012) 6120-6131.
[3] B. Scrosati, J. Garche, J. Power Sources 195 (2010) 2419-2430.
[4] F. Bertasi, C. Hettige, F. Sepehr, X. Bogle, G. Pagot, K. Vezzù, E. Negro, S.J. Paddison, S.G. Greenbaum, M. Vittadello, V. Di Noto. ChemSusChem. 8 (2015) 3069-3076.
[5] F. Bertasi, F. Sepehr, G. Pagot, S.J. Paddison, V. Di Noto. Adv. Funct. Mater. 2016, 26, 4860-4865.
[6] F. Bertasi, K. Vezzù, G. Nawn, G. Pagot, V. Di Noto. Electrochim. Acta. 2016, 219, 152-162.
[7] G. Pagot, F. Bertasi, K. Vezzù, F. Sepehr, X. Luo, G. Nawn, E. Negro, S.J. Paddison, V. Di Noto. Electrochim. Acta. 2017, 246, 916-923.
Engineered Electrolyte-Electrocatalyst Nanocomposites for Enhanced CO2 Electroreduction
Authors: Elgammal Ramez A. , Zawodzinski Thomas Anthony 
Published: December 2020

The development of a viable approach to capture, store, and convert carbon dioxide into fuels and chemicals may offer a means to mitigate climate change while also creating value added commodity chemicals. Critical bottlenecks in existing technologies that have impeded commercialization of CO2 electrosynthesis include catalysts with high overpotentials and limited selectivities. Furthermore, current approaches often employ PEM-based electrolyzers that suffer from low CO2 solubility in acidic aqueous solutions, limiting mass transport and reaction rates, or AEM-based systems which have much higher CO2 solubilites in alkaline electrolytes, but have the added problem of membrane poisoning by bicarbonate and carbonate.
We have recently developed an electrochemical reactor that overcomes many of the shortcomings that have limited the above technologies. Our preliminary results suggest that onset potentials for CO2 reduction are more than 200 mV lower than with current densities in excess of 150 mA/cm2 at -1 V vs RHE. The selectivities for CO are in excess of 90% and the electrocatalysts. We have examined several cathode electrocatalysts and some of the most promising include a series of nanostructured mixed and/or doped transition metal and main group metal oxides that also suppress the hydrogen evolution reaction. We will present detailed electrochemical and structural studies and will comment on possible reaction mechanisms as well as the key features of the reactor that enable the enhanced kinetics.
Zinc-Catalyzed Electrocatalytic Hydrogenation of Furfural at Neutral pH
Authors: Dhawan Manali , Yadav Ganapati Dadasaheb , Calabrese Barton Scott 
Published: December 2020

Electrocatalytic hydrogenation (ECH) of biomass-derived platform chemicals is a sustainable way to produce value added fuels and chemicals as compared to chemo-catalytic hydrogenation pathway [1,2]. In this work, ECH of furfural was carried out to produce furfuryl alcohol (FAL) and 2-methylfuran (MF) which have applications in pharmaceutical, polymer and fuel industries [1-3]. In this work, Zn metal was used as a novel catalyst for the ECH of furfural to study its yield and Faradaic efficiency (FE) for the desired products. The activity of Zn metal was compared to the well-known catalysts such as Cu and Ni. The effect of electrolyte pH was also studied, and it was found to significantly affect FE and product profile. Potentiostatic electrolysis in acidic and basic pH electrolytes suffered from poor product yield and FE, either due to dominant hydrogen evolution reaction (HER) or degradative electrodimerization and polymerization reactions. Electrolysis at neutral pH (pH 6 to 8) exhibited increased yields and FE as compared to acidic and basic pH. We correlate this to optimum proton concentration in neutral electrolytes that would restrict HER in addition to providing a pH atmosphere that would minimize side reactions. At neutral pH, the reaction was more selective towards FAL formation than MF. The best activity of Zn catalyst was obtained with 0.5 M sodium bicarbonate (NaHCO3) electrolyte (pH = 8.4) at -0.7 V/RHE with 77.5 % FE for FAL. The zinc catalyst displayed a total FE of 94 % for the ECH of furfural. At the same reaction conditions, the conversion, yield and FE for ECH with Zn was remarkably higher as compared to Cu and Ni metal electrodes. Zinc oxide precipitates were observed on the wire during electrolysis and were confirmed by EDS. The increased activity of Zn suggests a mechanistic role of adhered ZnO precipitates, possibly enhancing H adsorption and transfer to furfural.

References:

[1] Z. Li, S. Kelkar, C.H. Lam, K. Luczek, J.E. Jackson, D.J. Miller, C.M. Saffron, Aqueous electrocatalytic hydrogenation of furfural using a sacrificial anode, Electrochim. Acta. 64 (2012) 87–93. doi:10.1016/j.electacta.2011.12.105.
[2] X.H. Chadderdon, D.J. Chadderdon, J.E. Matthiesen, Y. Qiu, J.M. Carraher, J.P. Tessonnier, W. Li, Mechanisms of Furfural Reduction on Metal Electrodes: Distinguishing Pathways for Selective Hydrogenation of Bioderived Oxygenates, J. Am. Chem. Soc. 139 (2017) 14120–14128. doi:10.1021/jacs.7b06331.
[3] S. Jung, E.J. Biddinger, Electrocatalytic Hydrogenation and Hydrogenolysis of Furfural and the Impact of Homogeneous Side Reactions of Furanic Compounds in Acidic Electrolytes, ACS Sustain. Chem. Eng. 4 (2016) 6500–6508. doi:10.1021/acssuschemeng.6b01314.

Figure 1
(Invited) Anodic TiO2 Nanostructures for Photoelectrochemical and Photocatalytic Applications
Authors: Lee Kiyoung 
Published: December 2020

Since Zwelling et al. reported on anodized TiO2 nanotubes, many research groups have studied one-dimensional TiO2 nanotubes. This structure property can be controlled by pH, conductivity, fluoride concentration, base solution and applied potential and so on. TiO2 nanotubes are attracted attention owing to their variable function for use wide range applications such as photocatalyst, bio application, template and solar cell, etc. TiO2 nanotubes provide smooth electron pathway, less crystal defect to avoid electron recombination, high surface area for dye adsorption and the ability influence the adsorption and propagation of light.
In this presentation we give an overview of the latest results on TiO2 nanotube and porous structures. We will discuss critical factors to grow highly aligned and high aspect ratio anodic TiO2 nanostructures and the morphological variation by anodization parameters and their advantage for photocatalytic and photoelectrochemical applications.
Oer/ORR Properties of Massively Synthesized Nimos with Solvothermal Method
Authors: Choi Yusong , Ahn Tae-Young , Kim Jiyoun , Cho Janghyeon 
Published: December 2020

The oxygen electrode is the most critical component in lithium-air batteries for oxygen reduction and evolution reaction (ORR/OER) in order to get closer to the theoretical energy density of 11,238 Wh/kg, which is the best among the batteries ever developed. Many carbon materials have been researched as a candidate oxygen electrode for lithium-air batteries such as a carbon black, CNTs, and graphene. Compared to the many research results, there are still many controversies on the optimum oxygen electrode for lithium-air batteries. Besides that, carbon and binder have been known to deteriorate OER/ORR properties for lithium-air batteries by generating Li2CO3 and other bi-product.
Recently, HER and OER properties of heterogeneous MoS2/Ni3S2 have been reported for water splitting. The heterogeneous HER and OER performances of MoS2/Ni3S2 were better than the commercial HER and OER catalysts. Up till now, to my best knowledge, there is no report on ORR properties for homogeneous NiMoS. Therefore, in order to research the ORR properties of homogeneous NiMoS, the homogeneous NiMoS has been synthesized on Ni-foam and Ni-powder by various solvothermal methods such as applying stirring during solvothermal synthesis, increasing the pressure or applying the both. Finally, we successfully synthesized NiMoS massively with stirring at the pressure of 15 bar. Characterization for NiMoSs variously synthesized were conducted with SEM, TEM as well as OER/ORR properties using RRDE (Ring Rotating Disk Electrode).
As a result, homogeneous NiMoSs massively synthesized with stirring as well as high pressure of over 15 bar shows a unique homogeneous structure with sub-micron size. However, NiMoS synthesized under 2~3 bar pressure with no stirring shows the tens of micron size as well as heterogeneous structure. Intriguingly, OER/ORR properties of massively synthesized NiMoS shows much better OER/ORR properties compared to the solvothermally synthesized NiMoS with no-stirring and 2~3 bar pressure. These results show a very positive result for non-precious electrode material for next-generation Li-air battery as well as fuel cell field.
Silicon Microfabricated Preconcentrator Design and Characterization
Authors: Hesketh Peter J. , Struk Daniel , Paik Seung Joon , Navaei Milad , Chang Tzu-Hsuan , Doroshenko Vladimir M. , Dimandja Jean-Marie D. 
Published: December 2020

Abstract

MEMS fabrication technology has been applied to build micro-GC systems for portable analysis and detection of volatile organic compounds for environmental monitoring, medical diagnostics and food safety and security (1). Pioneering work at Sandia National Laboratories developed - these miniature systems (2). Novel designs for pre-concentrators have been developed to provide efficient sample injection into these systems (3). We have integrated a 6m length micro-GC column with an ion trap mass spectrometer (4). To inject the sample into the column, our initial method was to use a syringe injection into a heated septum with Agilent 6890. However, for automated operation and method of sampling, pre-concentration of the volatile organic compounds is required, followed by rapid heating, for sample injection for analysis. A microfabricated pre-concentrator can fulfill this function by providing a high surface area in a compact platform with reduced thermal mass, compared to commercial desorption tubes. The design has an integrated platinum heater and was fabricated using standard photolithography, deep reactive ion etching and wafer bonding. To evaluate the performance, the pre-concentrator is mounted inside a commercial Agilent 6890 GC system. Liquid injections 0.02uL, using a syringe, with a 100:1 split, at a helium flow rate of 0.005 ml/min. The flow rate was increased during the desorption cycle, and the preconcentrator was heated by electrical current of providing approx. 5W to enable rapid heating to 180°C. This miniature pre-concentrator provides a small thermal mass design and was capable of fast desorption of several analytes with detection by FID.

References

[1] M. Akbar, M. Restaino, M. Agah, “Chip-scale gas chromatography: From injection through detection,” Microsystems Nanoengineering, Vol. 1, pg. 15938 (2015).
[2] in J. J. Whiting, E. B. Myers, R. P. Manginell, M. W. Moorman, K. Pfeifer, J. M. Anderson, C. S. Fix, C. Washburn, A. Staton, D. Porter, D. Graf, D. R. Wheeler, J. Richards, K. E. Achuythan, M. Roukes, R. J. Simonson, "μChem Lab: twenty years of developing CBRNE detection systems with low false “μChemLab: twenty years of developing CBRNE detection systems with low false alarm rates”Proceedings of SPIE, Vo.l. 11010, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XX, 1101012 (17 May 2019); doi: 10.1117/12.2518778.
[3] Tian, Wei-Chang, H. K. L. Chan, Chia-Jung Lu, S. W. Pang, E. T. Zellers, “ Multiple-stage microfabricated preconcentrator-focuser for micro gas chromatography system,” J. Microelectromachanical Systems, Vol. 14, No. 3, pp 498-507 (2005).
[4] Tzu-Hsuan Chang, D. Struk, M. Navaei, V. M. Doroshenko; V. Laiko; E. Moskovets; K. Novoselov, J. D. Dimandja, Peter J. Hesketh, “Separation of Volatile Organic Compounds using of MEMS-GC Integrated Heater for Ion Trap Mass Spectrometer,” Sensors and Actuators B, Vol. 307, pg. 127588 (2020).