bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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).
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.