bluuebunny/crossref_metadata_2025 huggingface dataset:
PGM-Based Ammonia Oxidation Catalysts for Anion-Exchange Membrane Direct Ammonia Fuel Cells
Authors: Li Yi , Wu Gang
Published: September 2023

Low-temperature direct ammonia fuel cells (DAFCs) use carbon-neutral ammonia as a fuel, which has attracted increasing attention recently due to ammonia's low source-to-tank energy cost, easy transport and storage, and wide availability. However, current DAFC technologies are greatly limited by the kinetically sluggish ammonia oxidation reaction (AOR) at the anode. Herein, we report an AOR catalyst, in which ternary PtIrZn nanoparticles with an average size of 2.3 ± 0.2 nm were highly dispersed on a binary composite support comprising cerium oxide (CeO2) and zeolitic imidazolate framework-8 (ZIF-8)-derived carbon (PtIrZn/CeO2-ZIF-8) through a sonochemical-assisted synthesis method. The PtIrZn alloy, with the aid of abundant OHad provided by CeO2 and uniform particle dispersibility contributed by porous ZIF-8 carbon (surface area: ∼600 m2 g−1), has shown highly efficient catalytic activity for the AOR in alkaline media, superior to that of commercial PtIr/C. The rotating disk electrode (RDE) results indicate a lower onset potential (0.35 vs. 0.43 V), relative to the reversible hydrogen electrode at room temperature, and a decreased activation energy (∼36.7 vs. 50.8 kJ mol−1) relative to the PtIr/C catalyst. Notably, the PtIrZn/CeO2-ZIF-8 catalyst was assembled with a high-performance hydroxide anion-exchange membrane to fabricate an alkaline DAFC, reaching a peak power density of 91 mW cm−2. Unlike in aqueous electrolytes, supports play a critical role in improving uniform ionomer distribution and mass transport in the anode. PtIrZn nanoparticles on silicon dioxide (SiO2) integrated with carboxyl-functionalized carbon nanotubes (CNT–COOH) were further studied as the anode in a DAFC. A significantly enhanced peak power density of 314 mW cm−2 was achieved. Density functional theory calculations elucidated that Zn atoms in the PtIr alloy can reduce the theoretical limiting potential of *NH2 dehydrogenation to *NH by ∼0.1 V, which can be attributed to a Zn-modulated upshift of the Pt–Ir d-band that facilitates the N–H bond breakage.
Mechanistic Studies on CO2 Electroreduction on Ni{M}x-YSZ and Ce{M}Ox-YSZ
Authors: Kamboj Vipin , Raychowdury Soham , Ranjan Chinmoy
Published: September 2023

The conversion of CO2 to fuels via electroreduction can be instrumental in reducing dependence on fossil fuels and contributes to the global targets of CO2 reduction. The electrochemical reduction of CO2 to hydrocarbons, however, is kinetically limited by the fact that it is a multi-step process, with each step requiring the transfer of multiple electrons. On the other hand, the high temperature electrochemical reduction of CO2 to CO using a solid oxide electrolysis cell (SOEC) provides a route that is both energy efficient and cost effective. The CO thus produced can act as a value added product, as it can be directly used as a fuel, or it can be reduced into hydrocarbons via the well-known Fischer-Tropsch process. Ni/YSZ based electrodes are fairly ubiquitous in the field of solid oxide technologies. We have proposed the infiltration of Cu into Ni/YSZ to generate Ni{Cu}x-YSZ type cathodes, which exhibit improved performance for CO2 electroreduction at high temperature (~800 oC). The electrodes are prepared on commercial standard YSZ supports using Ni{Cu}x-YSZ mixtures for cathode and LSM-YSZ mixture for anode.

Most of the existing studies on high temperature reduction of CO2 on Ni/YSZ have been in the presence of safe gases, such as H2 or CO. The presence of H2 in the inlet stream created a reducing atmosphere on the electrode surface, and the reduction of CO2 proceeded through a thermochemical reverse water gas shift (RWGS) mechanism. (CO2 + H2 à CO + H2O). The presence of CO could lead to catalyst deactivation by Carbon deposition through Boudouard reaction (2CO à CO2 + C). Observations from such experiments led to the belief that metallic Ni in Ni/YSZ acts as the active species for CO2 reduction; and that the oxidation of the Ni to NiO leads to deactivation of the catalyst. By using operando Raman spectroscopy and online mass spectrometry, we have countered this idea and demonstrated that the electroreduction of CO2 on Ni-YSZ is mediated by a layer of NiOx on the electrode surface, which is the actual active species. CeOx is a well-known cathodic material for pure CO2 electroreduction. We have attempted to study the mechanistic aspects associated with CO2 electroreduction on Ce{M}Ox based systems as well.

Figure 1
Effects of Acid Leaching Post-Treatment Process on the Structural Stability of Pt-Based Intermetallic Catalysts for Fuel Cell Applications
Authors: Yang HyunWoo , Lee KwangHo , Cho EunAe
Published: September 2023

Accelerating the commercialization of polymer electrolyte membrane fuel cells (PEMFCs) requires urgent improvement of a catalyst for oxygen reduction reaction (ORR) that uses expensive precious metals. It is also important to consider the durability of the catalyst, which can affect its performance even after long-term use.

In this study, we synthesized a platinum-cobalt (Pt-Co) catalyst with a platinum (Pt) shell and an intermetallic inner core through the acid-leaching post-treatment process. By introducing a transition metal, we greatly improved the ORR activity, while controlling the intermetallic and core-shell structure greatly improved the catalyst's structural stability and durability. We confirmed through X-ray diffraction (XRD) that the Pt-Co compound was aligned in an intermetallic structure, and that the structure was maintained even after the acid leaching post-treatment. In the half-cell test, L10-PtCo@Pt/C, exposed to 0.5 M sulfuric acid solution for 6 hours, exhibited a 3.9-fold increase in mass activity and a 3.3-fold increase in specific activity compared to commercial Pt/C. Additionally, the electrochemical active surface area (ECSA) of L10-PtCo@Pt/C remained stable even after 30,000 cycles, with an insignificant change of 8% or less, while commercial Pt/C decreased by 30% or more. Nevertheless, when acid treatment was applied for longer than this condition, the increase in performance and its retention were significantly reduced. This is due to the fact that with longer acid leaching times, the Pt shell of the catalyst becomes thicker, resulting in a limitation of the alloying effect of the internal intermetallic core.

Our study proposes an optimal combination of Pt-Co intermetallic core and Pt shell through precise control of acid leaching post-treatment process. Pt-Co catalysts with well-aligned intermetallic core and the moderate thickness of Pt shell structure can offer a promising solution for improving the performance and durability of PEMFCs, thereby paving the way for their widespread commercialization.
Enhancing the Cathodic Performance of LSM Via Nanostructured Surface Decoration with Infiltrated Sm0.5Sr0.5CoO3-Δ
Authors: Baek Yun Jeong , Shin Tae Ho
Published: September 2023

The Solid Oxide Fuel Cell (SOFC) is getting attention from next-generation electrochemical energy conversion devices with high efficiency and low pollutant emission. But the high operating temperature in SOFC can lead to problems like high cost, difficult sealing, and fast degradation. To alleviate this problem, Intermediate temperature SOFC (IT-SOFC) has become an adequate alternative. But, as the operating temperature decreased, the Oxygen reduction reaction (ORR) also decreased, contributing to performance degradation and efficiency loss. The infiltration method, effectively improving the performance of the SOFC electrode, is one of the most effective ways. However, this method has been limited due to the multi-step process and instability of long-term operation. In this study, we suggest a new process that combines the infiltration and spray method with co-sintering to diminish the multi-step. We fabricated a cathode in which the LSM and Sm0.5Sr0.5CoO3-δ infiltration solvent coated simultaneously by the spray process and co-sintered. And we measured the cell performance and stability. Consequently, when applied as electrolyte-supported cells at 1073K, performance is measured by exhibiting a maximum power density of 0.986W cm-2 in fuel cell mode and electrolysis performance of 0.878A cm-2 at 1.3V. The result of this study was 0.724W higher than that of the bare LSM electrode.

Figure 1
Pt Single-Atom Catalysts Neighbouring Pt Nanoparticles with Synergistic Kinetics for Highly-Efficient Oxygen Reduction Reaction
Authors: Roh JeongHan , Cho Ara , Kim Minjun , Lee SangJae , Lee KwangHo , Liu Jing , Bak Junu , Lee Kug-Seung , Han Jeong Woo , Cho EunAe
Published: September 2023

Herein, we investigated the potential of downsizing Pt nanoparticles to single atom scale as a strategy to improve Pt utilization efficiency in electrocatalysts. We focused on Pt single atom catalysts anchored on high-surface area N-doped carbon[1-3], which have shown higher oxygen reduction reaction (ORR) activity than Pt nano-catalysts in fuel cell applications. However, the contribution of Pt nanoparticles in achieving these results has been questioned, and the selectivity of Pt SACs for ORR is still controversial. We prepared different types of carbon-supported Pt catalysts and used electrochemical measurements including rotating-ring disk electrode (RRDE) and hydrogen peroxide reduction reaction (HPRR) tests to elucidate the role of Pt SACs in carbon-supported Pt nano-catalysts. Additionally, we proposed a novel ORR mechanism based on in-situ X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations.

References

[1] Nat. Commun. 2017, 8, 15938

[2] Angew. Chem. 2019, 131, 1175

[3] ACS Catal. 2021, 11, 1, 466

Figure 1
Investigations of Biochar Steam Gasification for Integration with Proton Ceramic Fuel Cells
Authors: Muretta Julie E , McCurdy Thea , Kirtley John David
Published: September 2023

Typical anode materials used in proton ceramic fuel cells (PCFCs) are known to be resistant to both coking and sulfur poisoning, setting these devices apart from the more mature solid oxide fuel cells which still suffer from degradation issues. Thus, PCFCs may offer improved flexibility to operate with typically problematic bio-derived fuels such as sulfur-laden synthesis gas and methane. Steam gasification of biomass and biochar promises a viable option to generate synthesis gas fuel for use in fuel cells, but the fate of sulfur naturally present in these feedstocks is not fully known, and ppm-levels of gaseous sulfur in synthesis gas could prove problematic even for PCFCs. To investigate the potential for biochar gasification for production of low-sulfur, hydrogen-rich syngas, ground P. trichocarpa feedstock was pyrolyzed to 450° C and 700° C and subsequently gasified in 3%(vol.) steam at 700 ˚C. Water-leaching and CaCO3 coating of biomass prior to pyrolysis were additionally investigated as non-toxic, facile means of removing or reacting with (respectively) sulfates before those species could be converted to problematic organosulfur and gaseous sulfur (SO2, H2S, etc.) during pyrolysis and gasification. Gasification products from an updraft packed bed gasification reactor were tracked by quadrupole mass spectrometer, and solids before and after gasification were evaluated using Raman spectroscopy, SEM, and/or XRD. Preliminary results indicate that gasification in 3% (vol. in UHP Ar) steam can produce hydrogen- and methane-rich fuels low in H2S and SO2. Inorganics content and pyrolysis temperature suggest a synergistic effect on the production of H2, CO, CH4 and CO2 as well as H2S.

This research was sponsored by the Combat Capabilities Development Command Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-20-2-0163. The views and conclusions contained in this document are those of the authors, and should not be interpreted as representing the official policies, either expressed or implied, of the Combat Capabilities Development Command Army Research Laboratory or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.
Ternary Oxide Semiconductors and Alloys: Hope and Reality
Authors: Rajeshwar Krishnan
Published: September 2023

This perspective talk focuses on the history and status of new materials with targeted application in solar energy conversion. Specifically, photoelectrochemical energy conversion/solar water splitting and wide bandgap oxide semiconductors and alloys for solar windows and displays are the two targeted application areas. The Cu-M-V-O family of oxide semiconductors will be discussed in this poster. Both synthetic aspects and chemical composition-property-performance correlations will be presented.

Acknowledgements. This work was primarily supported by the National Science Foundation UTA/NU Partnership for Research and Education in Materials (NSF DMR-2122128).
Enhanced Durability of Nickel-Based Electrocatalysts for Oxygen Evolution Reaction (OER) at High Current Densities Using External Stimulation
Authors: Troy Lyra , Castro Raymond , Diaz-Abad Sergio , Chavez Luis A
Published: September 2023

Hydrogen (H2) is one of the most promising energy carriers for future clean energy production. The cleanest method to produce H2 is by water electrolysis using renewable electricity. Among electrolysis technologies, alkaline water electrolysis (AWE) is significantly cheaper than other techniques. While AWE is cost effective, it suffers from low power densities due to limited electrochemical stability at high current densities. Most stability challenges arise from anode degradation, where the oxygen evolution reaction (OER) occurs. The OER is key to achieve economic viability of AWE and current state-of-the-art electrocatalysts for OER are costly and scarce. Nickel-based catalysts are inexpensive, earth-abundant, and exhibit high OER performance but still exhibit durability challenges under high current densities. While several approaches have been reported to enhance durability of these catalysts, they are often complicated and time-consuming. We present a novel and simple method through which external stimulation can be used to enhance the durability of single metal catalysts. In this work, the durability of nickel-based electrocatalysts for OER under alkaline conditions (1 M NaOH) at high current densities was evaluated as a function of external stimulation in a chemically stable custom electrochemical cell. This cell was fabricated using additive manufacturing (AM), which enabled the direct application of external stimulation onto nickel-based materials in the cell. In addition, the performance of the electrocatalysts at high OER current densities for extended periods of time was measured as a function of various external stimulation parameters.

Acknowledgements

Financial support from the Los Alamos National Laboratory, Laboratory-Directed Research and Development (LDRD) is gratefully acknowledged. The authors would also like to thank the NNSA Minority Serving Institutes Partnership Program and LANL: Under-Represented Minority Partnership Program for their funding support.

References

Vij, Varun, et al. "Nickel-based electrocatalysts for energy-related applications: oxygen reduction, oxygen evolution, and hydrogen evolution reactions." Acs Catalysis10 (2017): 7196-7225.

Foroughi, Faranak, et al. "Understanding the Effects of Ultrasound (408 kHz) on the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) on Raney-Ni in Alkaline Media." Ultrasonics Sonochemistry 84 (2022): 105979.

Foroughi, Faranak, et al. "Sonoactivated polycrystalline Ni electrodes for alkaline oxygen evolution reaction." Ultrasonics Sonochemistry 86 (2022): 106013.
The Implementation of a Highly Efficient Hydrogen Generation System Producing High Purity Hydrogen in a Solid Oxide Electrolyser.
Authors: Pawlak Sylwia , Wijtiwiak Janusz
Published: September 2023

Solid Oxide Electrolyzer Cells (SOECs) stand out as one of the most efficient energy conversion technologies (i.e. enabling production of hydrogen fuel from surplus electrical energy), which is particularly well-suited for application in the distributed systems. While definitely very promising, until now SOEC technology is still not widespread, with the key technical limiting issues being i.a. high costs and deterioration of the operation parameters during prolonged operation. However, recently another major problem has become very urgent. Although most of the developed oxygen electrode materials are Co-based, there are strong reasons to mitigate the dependence on cobalt: deposits of Co ore are limited, and known commercial-level sources are localized in regions with volatile economic and unstable political situation; cobalt is classified as carcinogenic, and this fact leads to severe problems with public health especially at the mining sites; there are many examples of violations of the ecological standards in cobalt processing. In this work we propose modification of the bulk properties of the typical perovskite-type oxygen electrode material, La0.6Sr0.4Co0.2Fe0.8O3-δ, via chemical doping with Ni and Cu in order to limit usage of Co, while at the same time enhance properties of the materials to obtain excellent electrocatalytic activity.
(Digital Presentation) Ethanol Electro-Oxidation Kinetics Using Activated Carbon-Supported Pt-Ag Catalysts in Alkaline Media
Authors: Baruah Sarmistha , Kumar Akshai , Peela Nageswara Rao
Published: September 2023

Due to scarcity of fossil fuels and their severe environmental consequences, the development of high efficiency energy conversion devices such as fuel cells (FCs) have gained considerable attention. The specific energy conversion efficiency of FC is highly influenced by the activity of the electrocatalysts. The Pt is widely used as an electrocatalyst due to its high activity and stability, but its high cost and depletion of resources hinder its commercialization. One of the workable strategies for the practical application of Pt is to reduce its content by alloying with some non-precious metals and simultaneously maintain its electrochemical performance. In this context, we developed a low Pt-loaded Pt-Ag/C alloy electrocatalyst via a gradual reduction process. The electrochemical performance of the as-synthesized catalyst was investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) using the three-electrode electrochemical workstation at room temperature. The electrocatalytic investigations reveal that the resultant alloy has an activity of 32.7 mA cm-2, which is significantly higher than that of Pt/C (17.6 mA cm-2) in an alkaline electrolyte and makes it a very efficient electrocatalyst for the ethanol oxidation reaction (EOR). The partial electron transfer from Ag to Pt in Pt-Ag alloy, which weakens the CO binding and poisoning effect on the surface, may be partly responsible for the enhanced catalytic activity of Pt-Ag/C. The activated carbon support also favors charge transport by transferring charge from catalytic active sites to external circuits. The stability and durability studies reveal that Pt-Ag/C performs significantly better than Pt/C, making it a viable electrocatalyst for EOR.

Keywords: Direct Ethanol Fuel Cell, Electrochemical Impedance Spectroscopy, Cyclic Voltammetry, Alloy.
UV-Controlled Nitrene Crosslinking in Poly(phenylene oxide) Anion Exchange Membranes
Authors: Clemens Auston L. , Ceron Maira Raquel , Yassa Magi Mettry , Ferron Thomas , Barnett Adam , Hammons Joshua Aaron , Jayathilake Buddhinie , Molinero Valeria , Karnes John Joseph , Oakdale James Spencer
Published: September 2023

Anion exchange membranes (AEMs) promise significant capital cost saving associated with enabling use of Pt-group-free electrodes and components in alkaline fuel cells and electrolyzer devices. However, AEMs often lack the chemical and mechanical stability required for widespread commercial adoption. Crosslinking has proven to be an effective method to permit increased ion exchange capacity (IEC) while preventing exponential water uptake and retaining both conductivity and mechanical strength. In this work, we leverage molecular dynamics simulations to explore crosslinking methodologies in silico. We present a reproducible and quantitative UV-based nitrene chemistry that utilizes a mobile crosslinker that is straightforward to synthesize and implement. This crosslinking strategy significantly mitigates excess water uptake and improves alkaline stability without sacrificing IEC during the cure process. Additionally, we characterize electrochemically fielded AEMs by small angle X-ray scattering, mechanical strength testing, and other post-mortem analyses. The operational lifetime of crosslinked AEMs prepared in this work is 5 times greater than corresponding untreated AEMs.

This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 within the LDRD program 21-ERD-013. LLNL-ABS-848147.
(Digital Presentation) Kinetic Control of Angstrom-Scale Porosity in 2D Lattices for Direct Scalable Synthesis of Atomically Thin Proton Exchange Membranes
Authors: Kidambi Piran
Published: September 2023

Angstrom-scale pores introduced into atomically thin 2D materials offer transformative advances for proton exchange membranes in several energy applications. Here, we show that facile kinetic control of scalable chemical vapor deposition (CVD) can allow for direct formation of angstrom-scale proton-selective pores in monolayer graphene with significant hindrance to even small, hydrated ions (K+ diameter ∼6.6 Å) and gas molecules (H2 kinetic diameter ∼2.9 Å). We demonstrate centimeter-scale Nafion|Graphene|Nafion membranes with proton conductance ∼3.3–3.8 S cm–2 (graphene ∼12.7–24.6 S cm–2) and H+/K+ selectivity ∼6.2–44.2 with liquid electrolytes. The same membranes show proton conductance ∼4.6–4.8 S cm–2 (graphene ∼39.9–57.5 S cm–2) and extremely low H2 crossover ∼1.7 × 10–1 – 2.2 × 10–1 mA cm–2 (∼0.4 V, ∼25 °C) with H2 gas feed. We rationalize our findings via a resistance-based transport model and introduce a stacking approach that leverages combinatorial effects of interdefect distance and interlayer transport to allow for Nafion|Graphene|Graphene|Nafion membranes with H+/K+ selectivity ∼86.1 (at 1 M) and record low H2 crossover current density ∼2.5 × 10–2 mA cm–2, up to ∼90% lower than state-of-the-art ionomer Nafion membranes ∼2.7 × 10–1 mA cm–2 under identical conditions, while still maintaining proton conductance ∼4.2 S cm–2 (graphene stack ∼20.8 S cm–2) comparable to that for Nafion of ∼5.2 S cm–2. Our experimental insights enable functional atomically thin high flux proton exchange membranes with minimal crossover.

References:

1. Moehring N. K. et al. ACS Nano 2022, 16, 10, 16003–16018
Professor Petr Zuman: Life and Legacy
Authors: Krishnan Sadagopan , Rusling James
Published: September 2023

This lecture will address Prof. Zuman’s legacy and influence through the experiences of one of his scientific sons and one of his scientific grandsons. Petr was born and raised in the city of Prague during the rather tumultuous events of World War II. Early academic achievements after the war included a PhD in Physical Chemistry from Charles University in 1950, under future Nobel laureate Prof. J. Heyrovsky, who invited him to join the new Polarographic Institute in Prague in 1950. Shortly afterwards, Petr was appointed head of the Organic Electrochemistry Division of the Polarographic Institute and launched his research career in organic electrochemistry. He was both originator and major innovator in this area, which he focused on for the rest of his life. In 1967, he was awarded Dr. Science, Czech Acad. Sci. Also in this year, his influential monograph P. Zuman, Substituent Effects in Organic Polarography, was published.

In 1966 Petr took up to a guest professorship at University of Birmingham in the UK. In 1970, he moved to Clarkson University as Professor of Chemistry. In 1991, he retired as Distinguished Emeritus Research Professor, but kept active in research into his 90’s. Over his long career, Petr published nearly 500 papers and dozens of books, and mentored 100s of undergrads, grad students, and postdocs and other researchers. He was the ultimate pioneer in development of the field of Organic Electrochemistry, which is now gaining renewed popularity. This talk will also illustrate Petr’s influence on the research efforts of the authors.
Halogen Mediated Electrochemical Synthesis: Facial Accesses to Dibenzothiophenes and Spirooxindoles
Authors: Suga Seiji , Mitsudo Koichi , Sato Eisuke , Tachibana Yuri , Kangawa Sae
Published: September 2023

Electrochemical oxidative transformations using a halide as an oxidative mediator are useful for facial accesses to a variety of important organic compounds in the material and biological research fields. We have revealed the unique mediatory ability of anodically generated bromonium ion equivalent in the electrochemical synthesis of the thienoacenes [1].

In this presentation we will report two types of transformation using the mediatory system, which enable the formation of a series of crucial compounds. The first one is electrochemical synthesis of dibenzothiophene derivatives, one of the most important frameworks in the field of material science and pharmaceuticals. Several bis(biaryl) disulfides are efficiently converted to dibenzothiophenes by the electrochemical oxidation [2]. The second is the semi-pinacol rearrangement of tetrahydro-β-carbolines affording 3-spirooxindoles, which have unique three-dimensional structures and potent bioactivity [3]. In these reactions, the anodically generated bromonium ion equivalent as a halogen mediator was essential and efficiently promoted the transformation.

[1] Mitsudo, K.; Matsuo, R.; Yonezawa, T.; Inoue, H.; Mandai, H.; Suga, S: Angew. Chem. Int. Ed. 2020, 59, 7803−7807.

[2] Mitsudo, K.; Tachibana, Y.; Sato, E.; Suga, S: Org. Lett. 2022, 24, 8547−8552.

[3] Sato, E.; Kangawa, S.; Mitsudo, K.; Suga, S. Chem. Lett. 2022, 51, 1067–1069.
Cathodic Oxidation of Alkanes Using Molecular Oxygen
Authors: Waldvogel Siegfried R
Published: September 2023

The electrochemical conversion of less activated substrates provides an attractive approach to convert such substances into valuable intermediates. Electrosynthesis represents a future technology, which is characterized by its outstanding sustainability.[1]

A new way is presented to electrochemically convert alkanes and alkenes into the oxygenated species by cathodically activated molecular oxygen. This method allows the use to side streams in industry and substitutes conventional techniques which rely on the use of fuming nitric acid. Consequently, electrosynthesis will contribute to less climate damaging processes.[2]

By detailed mechanistic studies, the electrosynthetic concourse could be elucidated and will be discussed in detail.

References:

[1] D. Pollok, S. R. Waldvogel, Chem. Sci.
2020, 11, 12375–12592.

[2] J. Nikl, K. Hofman, S. Mossazghi, I. C. Möller, D. M. Mondeshki, F. Weinelt, F. Baumann 2022, submitted.
Structure and Reactivity of Metal-Oxide-Supported Noble Metal Nanoparticles: Electrooxidation of Simple Organic Molecules
Authors: Kulesza Pawel J. , Rutkowska Iwona A.
Published: September 2023

There has been growing interest in utilizing small (simple) organic molecules, as alternative fuels to hydrogen, in electrochemical energy conversion systems. In addition to ethanol (biofuel), that can be ideally oxidized to carbon dioxide thus delivering twelve electrons, recent important systems include dimethyl ether as well. But realistically the respective reaction is rather slow at ambient conditions. Obviously, there is a need to develop novel electrocatalytic materials.

Platinum has been recognized as the most active catalytic metal towards oxidation of ethanol at low and moderate temperatures. But Pt anodes are readily poisoned by the strongly adsorbed intermediates, namely by CO-type species, requiring fairly high overpotentials for their removal. To enhance activity of Pt catalysts towards methanol and ethanol oxidation, additional metals including ruthenium, tin, molybdenum, tungsten or rhodium are usually introduced as the alloying component. More recently it has been demonstrated that catalytic activity of platinum-based nanoparticles towards electrooxidation of ethanol has been significantly enhanced through interfacial modification with ultra-thin monolayer-type films of metal oxo species of tungsten, titanium or zirconium.

We pursue a concept of utilization of mixed metal (e.g. zirconium/tungsten or titanium/tungsten) oxide matrices for supporting and activating noble metal nanoparticles (e.g. PtRu) during electrooxidation of methanol, ethanol, formic acid and dimethyl ether. Among important issues is incorporation of Rh nanostructures capable of weakening, or even breaking, the C-C bond in the ethanol molecules. On the other hand, rhodium itself is not directly electrocatalytic toward oxidation of ethanol. The oxides and noble metal nanoparticles have been deposited in a controlled manner using the layer-by-layer method. Remarkable increases of electrocatalytic currents measured under voltammetric and chronoamperometric conditions have been observed. The most likely explanation takes into account possibility of specific interactions of noble metals with transition metal oxide species as well as existence of active hydroxyl groups in the vicinity of catalytic noble metal sites. In addition, formation of “nanoreactors” where ethanol is partitioned (at Rh) to methanolic residues further oxidized at PtRu cannot be excluded.
Electrochemically Generated Platform Oxidizers for Pharmaceutical Production
Authors: Waldvogel Siegfried R
Published: September 2023

Periodates represent one of the most powerful and versatile oxidizers in organic synthesis. Common ways to generate it electrochemically employ lead dioxide anodes. The disintegration of these electrodes cause contaminations which impede sensitive applications.[1] The purification of periodates makes this reagent usually too costly for pharmaceutical applications. With the use of boron-doped diamond anodes, a direct conversion of the inexpensive sodium and potassium iodide within an eight-electron oxidation process renders periodate. The novel process is scalable, heavy metal-free and can be conducted in batch as well as flow electrolyzers.[2] This approach can also be used for the regeneration of periodates from iodates and other iodine sources (waste streams). The process was implemented in a new synthetic approach to levetiracetam, which demonstrates the technical application and recycling of iodates in API synthesis.[3] This reagent can also be employed to make sulfoximines and degrade lignins to elaborated building blocks. [4, 5] The reactor concepts for the efficient preparation of multi-kg quantities will be presented. [6]

References:

[1] D. Pollok, S. R. Waldvogel, Chem. Sci. 11 (2020) 12375–12592.

[2] S. Arndt, D. Weis, K. Donsbach, S. R. Waldvogel, Angew. Chem. Int. Ed.
132
,
(2020) 8112-8118.

[3] S. Arndt, B. Grill, H. Schwab, G. Steinkellner, U. Pogorevčnik, D. Weis, A. M. Nauth, T. Opatz, K. Donsbach, S. R. Waldvogel, M. Winkler, Green Chem. 23 (
2020) 388–395.

[4] M. Klein, S. R. Waldvogel, Angew. Chem. Int. Ed. 60 (2021) 23197–23201.

[5] J. Klein, K. Alt, S. R. Waldvogel, Adv. Sustainable Syst. 6 (2021) 2100391.

[6] S. Arndt, R. Rücker, A. Stenglein, S. R. Waldvogel, Org. Process Res. Dev. 26 (2022) 2447−2455.
Air-Stable Semiconducting Ionic Polymers for Thermoelectric Applications
Authors: Chen Nan , Katz Howard E.
Published: September 2023

Thermoelectric (TE) devices that interconvert heat and electricity are the promising tools to harvest waste heat and solve energy problems. The current TE market is dominated by inorganic materials such as Bi2Te3 due to their excellent TE performance; however, the issues of inorganics that involve material toxicity, rigidity, heavy weight and energy-intensive processing techniques are limiting the wide applications of TE devices. Choosing organic materials that are light weight, mechanically flexible, abundant and require low-temperature processing, as in our research focus, is paving the path to sustainability and opening up opportunities for a variety of applications such as electronic wearables and sensors.

In our study, we aim to design and develop sensors that can detect high electric-field utilizing air-stable ionic polymer TE systems, a novel type of organic semiconductors, via a facile, solution-processing technique. We selected two n-type chloride-based ionic polymers, MADQUAT and PDADMAC as our starting materials because they have relatively low yet reliable ionic conductivities and intrinsically high Seebeck Coefficients under dry condition. The key challenge was that chloride-based polymers were extremely unstable due to their sensitivity to air/moisture and polymer relaxation. We adopted a solution-processable anion exchange technique and successfully created new systems with the same cationic polymer chain but various anions such as tetrafluoroborate (BF4
-) and hexafluorophosphate (PF6
-), that are more hydrophobic, increasing the system stability. Currently, we are investigating our stable ionic polymer TE performance by applying high voltages (500V-2000V) laterally across the samples through a pair of electrodes thermally evaporated on top. The change in TE properties after the high E-field application will help us probe further into the ionic movement of the polymeric systems thermodynamically and kinetically and understand what determines the p/n-type behavior. The thermoelectric sensor for high E-field detection can be incorporated into devices that can detect planetary objects in the outer space as well as microscale biological systems.
Bio-Inspired Polymer Design for Enhanced Microbial Electrocatalysis
Authors: Agee Alec , Furst Ariel L
Published: September 2023

Microbial electrocatalysis is an emerging technology which enables electricity generation directly from organic feedstocks, many of which are otherwise difficult to harness for renewable energy. While microbes possess unique advantages for these applications, their use in practical settings is currently limited by inefficient electron transfer from cells to electrodes. To address this bottleneck, we have developed improved electrode materials that combine principles of conductive polymer design with lessons from enzymatic electron transfer reactions. Our polymer electrodes exhibit superior nanoscale electroactive area and enable concerted two-electron transfer from the electron carrier flavin mononucleotide (FMN) to an abiotic surface, a high efficiency mechanism which was previously restricted to biological contexts. Electroactive microbes exhibited greatly improved current production on polymer electrodes in quantitative agreement with in vitro electrochemical properties. Our findings establish bio-inspired functionalization as a useful paradigm to bridge the gap between microbial metabolism and abiotic electrochemistry.
Unraveling Electrochemical Lignin Degradation in Organic Solvent for Production of Valuable Fuels and Chemicals
Authors: Hasan Mahmudul , Greenlee Lauren F
Published: September 2023

Lignin is the second most abundant biopolymer in nature after cellulose. Due to its distinctive aromatic backbone, it is also one of the most unique biopolymers. The aromatic components in lignin provide structural support to plants and comprises about 30% of the plant material. These aromatic groups can be used to produce renewable aromatic compounds. Also, these aromatic compounds can be used to produce biofuels which can be promising alternative to fossil-based fuels and chemicals. Besides, from previous studies it is found that about 40 to 60 million tons of lignin are generated from pulp and paper industry, mostly as wastes. So, developing novel and attractive strategies for fragmentation of lignin is gaining increased interest among scientific community for valorizing this underexploited material. Also, by valorizing lignin the sustainability of biorefinery and paper industry can be enhanced. However, the present technologies used for degradation of lignin generally requires the use of metallic catalysts at high temperatures and harsh reaction conditions. As a result, catalyst recovery and decomposition often become difficult under such harsh conditions and the process becomes impractical. Also, these technologies suffer from poor selectivity and usually produce the desired fragmentation products in low yields. Compared to the thermocatalytic transformation of lignin, electrocatalytic approaches have several advantages like it is environmentally friendly, have mild reaction conditions and the cost is low. Besides, there is a lack of studies incorporating electrocatalytic oxidation and reduction of lignin in organic solvent. In this project, the main goal was to overcome the challenge of using isolated lignin from various industrial processes by electrochemical depolymerization of lignin in organic solvent like tetrahydrofuran. Tetrahydrofuran is mainly used in Co-solvent Enhanced Lignocellulosic Fractionation (CELF) process. So, electrocatalytic degradation of lignin in this solvent is beneficial because the product from CELF process can be directly used here and thus it can work as a secondary treatment process for CELF process. Cyclic voltammetry (CV) and Chronoamperometry (CA) which are important tools for identifying redox reactions happening in the system is used here. In this presentation, for varying concentrations of Lignin, Tetrahydrofuran and sulfuric acid the results found from CV and CA will be discussed with practical significance.

Keywords: Recalcitrant biopolymer, Lignin in organic solvent, controlled electrocatalysis, secondary treatment for CELF process, Cyclic Voltammetry
(Digital Presentation) A Review on the Control of Biofilms by Cold-Plasma Technology
Authors: Abbassi Shanbehbazari Mohammad Sadegh , Abbassi Shanbehbazari Mohammad Kazem , Ostovarpour Farzaneh , Khani Mohammad Reza , Akbartehrani Pouria , Rouhbakhsh Jorshari Ahmad , Rasoul Khomeini Maryam , Shokri Babak
Published: September 2023

Today, biofilm infection is considered a challenge in the field of medicine and biomedical physics and engineering, as it includes 80% of infections worldwide. The complex architecture of the matrix of the extracellular polymeric substance of the biofilm, which houses the microbial cells, is resistant to antimicrobials and detergents. Cold Plasma anti-bio film application is a novel solution to address this challenge. This review study focuses on different parameters and factors affecting the mechanism of plasma-biofilm interaction in two types: direct and indirect processing. The first phase, the direct application of plasma, focuses on the direct processing of biofilms by cold plasma generators. The second phase, the indirect application of plasma is dealt with plasma surface engineering for biomaterial and medical devices which are in contact with the human body. As is known reduction in microbial load and biofilm removal by direct plasma processing is achievable and efficient. This microbial reduction also can happen by plasma surface engineering as an indirect solution, in which the plasma-treated biomaterial surface will gain an antimicrobial property and consequently mitigate biofilm growth. Moreover, the penetration depth of plasma in biofilms and the application of plasma surface pretreatment with 3D printing as a next-generation manufacturing approach have been reviewed. This review study sheds light on the efficient factors in this mechanism. This clarification helps how to optimize the control of biofilms by cold plasma technology.
Electrochemical Oxidation of 4-(Hydroxymethyl)Benzoic Acid
Authors: Qiu Jingjing , Ragan Zachary
Published: September 2023

We have investigated the electrochemical oxidation of 4-(hydroxymethyl)benzoic acid (4-HMBA) on different metallic working electrodes in alkaline electrolytes, including gold (Au), nickel (Ni), and platinum (Pt) metal. Au shows the lowest onset potential for catalyzing the electrooxidation of 4-HMBA among the three metals in base, whereas Pt does not catalyze the electrooxidation of 4-HMBA under alkaline conditions. The products of electrochemical oxidation of 4-HMBA catalyzed on Au working electrode are 4-carboxybenzaldehyde and terephthalic acid analyzed by high-performance liquid chromatography. The electrodeposited Au nanostructures on indium tin oxide (ITO)-coated glass is further utilized as the working electrode and catalyst for the 4-HMBA electrooxidation by introducing the plasmonic effects of the Au nanostructures. With the broad absorption of the Au nanostructures anchored on the ITO substrate in the visible and near-infrared range, we show that they could enhance the electrochemical oxidation of 4-HMBA under green and red LED light illuminations. The plasmonic effects of the Au nanostructures are proposed to contribute to the enhancement of the reaction and the photothermal effect is excluded based on electrolyte-temperature-dependent measurements. A possible reaction mechanism is proposed for the electrochemical oxidation of 4-HMBA on Au working electrodes in an alkaline electrolyte. Ongoing work focuses on investigating the electrochemical oxidation of electronically unique aromatic substituents of 4-HMBA and the plasmonic effects from the Au nanostructure electrodes in assisting other electrochemical reactions.
Transport in Ion-Exchange Membranes with Ternary Solutions of Salt, Water and Alcohol Relevant for (Reverse) Electrodialysis
Authors: Solberg Simon Birger Byremo , Burheim Odne Stokke , Grieg Joachim Willumsen
Published: September 2023

Leaching of Li-ion battery components in sulfuric acid followed by precipitation with ethanol has been proposed as a route for material recycling [1]. Cobalt, copper and lithium were then recovered as sulphate salts. The final mixture of dilute salts, water and ethanol may be further processed using ion-exchange membranes and electrodialysis to separate salts and water from ethanol, with the aim of increasing salt recovery and allowing for the re-use of the spent ethanol. We investigate the effect of alcohol on the transport numbers, resistance and the thermodynamic properties of the membrane and the aqueous solutions of alcohol, water and salt. This has implications for the electrodialysis of alcohol-containing mixtures, as well as for the application of this working fluid to a power-producing reverse electrodialysis system.

[1] S. Aktas, D. J. Fray, O. Burheim, J. Fenstad & E. Açma, Recovery of metallic values from spent Li ion secondary batteries.
Microfluidic-Assisted Alignment of Graphene Nanosheets for Microfiber Formation
Authors: Subedi Vivek , Modi Bindu , Ross Ashley E
Published: September 2023

Recently, our lab developed graphene oxide microfibers for ultrasensitive neurochemical detection with fast-scan cyclic voltammetry (FSCV). Graphene-fiber microelectrodes provide a significant advance over traditional carbon-fiber microelectrodes due to their resistance to detrimental fouling, fast electron transfer kinetics, and frequency independent behavior. Despite our recent advancement, there still exists a gap in our understanding of how specific changes in the carbon chemical structure influences adsorption and interaction of various neurochemicals at the surface. Understanding the extent to which the carbon chemical structure influences electrochemical detection is critical for designing tailor-made electrodes for ultrasensitive analyte detection. From a molecular level point-of-view, the graphene sheet consists of two regions with different structure: i) the basal plane, consisting of conjugated sp2 hybridized carbon atoms, and characterized by an atomic flatness and low defect density; and ii) the edge plane, that forms sp3 sites with a high level of defects and a variety of functional groups and dangling bonds. It is generally believed that the electrochemical properties of the basal and edge plane are significantly different, however, there has been debate concerning the electrochemical activity at the basal and edge plane. The conventional consensus is that electron transfer kinetics is faster on the edge plane in comparison with the basal plane sites, while the opposite barrier of this debate provides evidence for fast electron transfer at pristine basal plane. Moreover, how these factors influence neurochemical detection, particularly at rapid scan rates, is still lacking due to the necessity of using microelectrodes with FSCV. To date, most studies analyzing the influence of basal vs. edge plane surfaces on electrochemical detection have used macroelectrodes like highly ordered pyrolytic graphite (HOPG) which are not amenable to FSCV detection due to the large capacitive currents obtained at macroelectrodes at scan rates consisting of hundreds of volts per second. Therefore, to address this existing knowledge gap in understanding how edge vs. basal planes influence subsecond neurochemical detection, the ability to develop microelectrodes with controlled surfaces is crucial. Here, I will discuss our labs latest effort in developing graphene oxide microfibers with controllable nanosheet alignment to study the influence of basal vs. edge plane availability on neurochemical detection at rapid scan rates. To assist in nanosheet alignment, we use microfluidic channels to assist in fluid-driven control of nanosheet orientation. Using microfluidics to help develop highly controllable electrode materials provides a critical advance in our ability to develop novel carbon surfaces for detection.
Degradation of Solid Oxide Fuel Cell Using Thin Film Electrodes Fueled By Carbon Monoxide-Hydrogen Syngas
Authors: Lee Myung Seok , Cha Suk Won
Published: September 2023

According to the recent development trend of the smart farm industry, solid oxide fuel cells are emerging as a sustainable power source due to their high fuel efficiency and fuel flexibility which includes carbon fuels such as carbon monoxide. This study conducted a series of experiments to secure an operation strategy for a solid oxide fuel cell operating at the intermediate temperature of 650~800C. Although it is known that when a fuel cell is operated using carbon-based fuel at an intermediate temperature under 800C, fatal degradation occurs due to carbon coking, widely used commercial fuel cell stacks were manufactured not to exceed that temperature. To simulate a commercial fuel cell stack, the experiment was conducted in the commercial operating temperature range, and nickel-yttria stabilized zirconia was used as anode material. Additionally, ceria-based anode material was applied, and compared its single-cell performance with that of the yttria-based anode material. Carbon monoxide-hydrogen mixed fuel, which can be produced through torrefaction and fuelization from agricultural by-products, was supplied. To this end, a YSZ-based electrolyte-supported cell using Ni-YSZ/Ni-GDC and LSCF-GDC as anode and cathode materials, respectively, was fabricated by the sputtering method. The cell performance and degradation phenomenon were measured under the two temperature ranges and two fuel supply conditions. For structural analysis, FE-SEM and FIB-SEM methods were conducted, and techniques such as the i-V-P curve, EIS, and DRT were used for their electrochemical analysis. The relationship between the nano-scaled structural change caused by the carbon coking phenomenon and the cell performance was derived. Especially, EDS mapping and XPS analyses were conducted to quantify the carbon coking phenomenon. Through this, the degradation mechanism mainly caused by carbon coking was analyzed when syngas was used as a fuel. The optimal operating condition for durable fuel cell performance was confirmed for the stack-sized operation in the smart farm industry.