bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrocatalytic Synthesis of Ammonia and Urea
Authors: Costa Figueiredo Marta 
Published: November 2022

Many industrial chemical processes involve a high-energy demand (often still derived from fossil fuels), toxic reactants, and the production of high amounts of waste. A good example is the production of ammonia and urea via the Haber-Bosh and Bosch-Meiser processes, respectively. These two nitrogen-containing compounds are mostly used in the fertilizer industry and with the increase in the world population, their production is expected to increase. Additionally, NH3 itself is responsible for 2% of the annual world energy consumption and has a carbon footprint of 1.5 tons of CO2 per ton of NH3 [1]. Therefore, the development of more efficient, less hazardous technologies that are based on renewable energies to produce valuable N- containing compounds, has become one of the most challenging topics for chemical synthesis. By using electrochemical methods for the synthesis of ammonia and urea, toxic and dangerous chemicals can be replaced with clean electrons. Furthermore, the efficiency and selectivity of the reactions can be tuned by the applied potential, and more importantly, the energy used can come from renewable sources like wind or solar [2].
In this talk, I will show the recent advances from our group in the development of catalysts for the electrocatalytic synthesis of ammonia and urea (as for example Cu2O and CuRh) and the reaction mechanism when using nitrate as a substrate [3].

References:

[1] S. Giddey, et al, Int. J. Hydrogen Energy, 38 (2013) 14576–14594
[2] Frontana-Uribe, B. A. et al; Green Chem. 2010, 12 (12) 2099– 2119
[3] D. Anastasiadou, Y. van Beek, M. C. Figueiredo, in preparation.
Figure 1: SEM images of two electrodeposited electrocatalysts used for ammonia and urea electrosynthesis from nitrates: a) CuRh and b) CuO.

Figure 1
Tunning Copper Sulfide Nanocatalysts for an Efficient Electrochemical Nitrogen Reduction
Authors: Jin Haneul , Choi Jihyun , Kim Seung-hoon , Park Hyun S. , Yoo Sung Jong 
Published: November 2022

Electrocatalytic performance depends on the surface characteristics of catalysts. Understanding the determinants for adsorption of the reactants and desorption of the products is essential for efficient electrocatalyst design. Electrochemical nitrogen reduction (eNRR) is initiated by nitrogen adsorption and is progressed by hydrogenation to produce ammonia. Despite the intensive development of eNRR catalysts, optimum catalyst design for eNRR is barely understood. Here, we report a designer approach study for investigating the relationship between catalyst surface features (surface geometry and composition) and eNRR performances. To test our idea, facet-controlled copper sulfide hexagonal nanoprisms which only expose two types of facets, {100} and {010}, were deliberately prepared. We studied exposed facet density-dependent eNRR performances by controlling aspect ratios of the Cu1.81S nanoprisms. Thereafter, we tested surface dopant effects on eNRR activity and stability by introducing heteroatoms on the Cu1.81S nanoprisms. Physical and electrochemical properties of the catalysts were investigated by TEM, CV, and DFT analyses and it is discovered that protruded surfaces are active for the eNRR and dopant enhances the eNRR performances.
References

Zhao, X.; Hu, G.; Chen, G. F.; Zhang, H.; Zhang, S.; and Wang, H., Mater, 33, 2007650 (2021).

Kim, H. S.; Choi, J.; Kong, J.; Kim, H.; Yoo, S. J.; and Park, H. S., ACS Catal. 11, 435 (2020).
Electrochemical Synthesis of Ammonia from Nitrogen and Nitric Oxide at Room Temperature over Nanostructured Transition Metal Catalysts
Authors: Shanmugam Sangaraju , Markandaraj Sridhar Sethuram 
Published: November 2022

Transition metals have been recognized as excellent and efficient catalysts for transforming gaseous molecules into value-added chemicals. Electrochemical ammonia synthesis through the atmospheric reduction of nitrogen and nitrogen oxide is a promising method for sustainable fertilizer and carbon-free hydrogen energy carriers. However, it is a great challenge to main the activity and stability of the catalyst due to its corrosive nature and vigorous reaction conditions involved in the electrochemical transformations.
We report stable core-shell electrocatalysts that utilize transition metal nanoparticles in the core and nitrogen-doped porous carbon architecture in the shell for the efficient electroreduction of N2 and NO to ammonia (NH3). The carbon shell prevents the dissolution of Ni nanoparticles. It ensures the long-term stability of the catalyst, whereas the Ni nanoparticles involve in the catalytic reduction of NO to NH3 during electrolysis. The catalyst images reveal a core-shell structure composed of dark metallic spherical particles at the core and layered carbon as a shell surrounding the nanoparticles (Fig. 1a). A broad particle size distribution of 15 nm to 50 nm was observed, and the core-shell particles were interconnected by a smooth carbon matrix. The heteroatom content and the shell thickness strongly influence the catalytic activity. A high faradaic efficiency (FE) of 72.3% at 0.16 VRHE is achieved (Fig. 1b). Moreover, the full-cell electrolyzer was constructed by coupling developed cathodes and commercial RuO2 as anode for oxygen evolution reaction, which delivered a stable performance over several cycles at 1.5 V. Further, we demonstrate the solar to fuel transformation by integrating with a PV-electrolyzer cell, it presented an appreciable FE of >50%.
Fig. 1. (a) TEM image of core-shell catalyst, (b) comparison of FE and NH3 yields on various electrocatalysts for the nitric oxide reduction reaction.

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Electrocatalytic Conversion of Methane to Ethylene Utilizing Highly Durable Barium Niobate Perovskites
Authors: Denoyer Luke H , Benavidez Angelica , Garzon Fernando H. , Ramaiyan Kannan 
Published: November 2022

Pursuing efficient conversion of methane to value-added products such as olefins and aromatics is a prospective use of natural methane feedstocks. The demand for on-site methane conversion has further increased due to the recent discoveries of shale gas reserves. Electrochemical methane conversion provides a means to control the surface oxide ion concentration, aiming to eliminate the over-oxidation of methane while also aiding in methane activation via applied potential. High temperature electrolysis processes provide improved reaction kinetics. Unfortunately, high temperature operation also leads to material degradation via sintering, crystal structure disproportion to thermodynamically more stable phases, and interfacial reactions that reduce performance. We demonstrated that the Sr2Fe1.5Mo0.5O6-
d (SFMO) perovskite which was reported with desirable methane activation properties had poor chemical and electrochemical stability as it formed carbonates and coke under methane rich environments.[1][2] Here we present an exciting class of barium niobate perovskite materials with varying levels of Mg and Fe co-doping that show promising catalytic activity towards methane activation in the electrochemical and conventional heterogeneous oxidative coupling environment. The perovskite material was prepared by conventional solid-state methods and by microwave synthesis methods to compare the role of surface area. Thermogravimetric analysis and temperature programmed reaction measurements under methane show superior chemical stability in comparison to SFMO perovskites. These catalysts’ electrochemical properties are evaluated by cyclic voltammetry, impedance spectroscopy, and chronoamperometric measurements coupled with mass spectra analysis that demonstrate durable operation for five continuous days. A maximum ethylene production of 277 mmolcm-2h-1 with a faradaic efficiency of 20% at 1V was obtained. Stability determinations of our perovskite oxide electrocatalysts for EC-OCM offer an excellent example of our approach towards evaluation of materials durability under the highly carburizing environments. These perovskite materials could also serve as a support for a wide variety of catalyst materials for high temperature applications thus opening new possibilities.

References

[1] K. P. Ramaiyan, L. H. Denoyer, A. Benavidez, and F. H. Garzon, “Selective electrochemical oxidative coupling of methane mediated by Sr2Fe1.5Mo0.5O6-δ and its chemical stability,” Commun. Chem., vol. 4, no. 1, p. 139, 2021, doi: 10.1038/s42004-021-00568-1.
[2] C. Zhu, S. Hou, X. Hu, J. Lu, F. Chen, and K. Xie, “Electrochemical conversion of methane to ethylene in a solid oxide electrolyzer,” Nat. Commun., vol. 10, no. 1, p. 1173, 2019, doi: 10.1038/s41467-019-09083-3.

Figure 1
Development of Highly-Efficient CO2 Electrolysis Cell Stacks
Authors: Kiyota Yasuhiro , Kofuji Yusuke , Ono Akihiko , Mikoshiba Satoshi , Kitagawa Ryota 
Published: November 2022

Low-temperature CO2 electrolysis technology, which converts CO2 into valuable products, has attracted attention for its potential to mitigate climate change caused by global warming. Various products, such as CO and ethylene glycol, can be obtained from electrochemical reactions [1,2]. CO, a useful raw material for hydrocarbons, is a particularly simple product. In order to implement an industrial-scale low-temperature CO2 electrolysis system, we must further reinforce the properties of the CO2 electrolysis cell: namely, energetic (energy conversion) efficiency, CO2 conversion rate (current density and scaling) and durability. For realizing high energetic efficiency, decreasing ohmic resistance and overvoltage is required. Therefore, a zero-gap electrolysis cell, which has short electrodes distance leading to lower ohmic resistance, has been adopted. The zero-gap configuration contains a membrane electrode assembly (MEA) constructed from cathode and anode electrodes and a diaphragm. Anion exchange membranes (AEMs) have been mainly used in past research as the diaphragm, however, the AEMs have several shortcomings for practical use as the diaphragm, e.g., low thermal stability, weak mechanical strength and high cost.
In this work, we have focused on porous membranes as a novel diaphragm which is more suitable for overcoming those instabilities and costs. We have achieved an increase in energetic efficiency of the zero-gap CO2 electrolysis cell using the porous membrane when compared to that of AEMs. We have experimentally revealed higher ion permeability, lower ohmic resistance and lower overvoltage when using the porous membrane, resulting in improvement of the energetic efficiency. Regarding CO2 conversion rate and durability, we have developed a large-scale cell stack constructed with ten layers of a 100 cm2 size cell and demonstrated durable operation over one month.
This work is partially supported by the Ministry of the Environment, Government of Japan.
[1] Y. Kofuji, A. Ono, Y. Sugano, A. Motoshige, Y. Kudo, M. Yamagiwa, J. Tamura, S. Mikoshiba and R. Kitagawa, Chem. Lett.
50, 482 (2021).
[2] J. Tamura, A. Ono, Y. Sugano, C. Huang, N. Hideyuki, and S. Mikoshiba, Phys. Chem. Chem. Phys.
17, 26072 (2015).
Anode Catalysts for Solid Oxide Fuel Cells That Run Directly on Hydrocarbon Fuels
Authors: Zhang Weilin , Zhou Yucun , Luo Zheyu , Nam Gyutae , Liu Meilin 
Published: November 2022

Solid oxide fuel cells (SOFCs) can efficiently generate electricity from a wide variety of fuels, offering unique advantages over the conventional power generation systems based on combustion. In particular, SOFCs can directly use low-cost and readily available hydrocarbon fuels as the energy source. To be commercially competitive, however, breakthroughs in materials development is required. For instance, a durable and electro-catalytically active anode material or catalyst is needed that can facilitate hydrocarbon reforming and avoiding carbon deposition (coking) for SOFCs to operate stably on hydrocarbon fuels, including natural gas, ethanol, and iso-octane.
Hydrocarbon fuels, especially liquid ones, have several advantages over hydrogen fuel: low-cost, high volumetric energy density, and ease for transportation and storage. Currently, direct-hydrocarbon SOFCs suffer from severe performance degradation due to carbon deposition. In this presentation, we report a promising anode catalyst for SOFCs operated on various hydrocarbon fuels, from methane to ethanol and iso-octane. The catalyst has been successfully applied to both small button cells and tubular cells with an effective area of about 38 cm2. For both cases, our cells demonstrate stable performance for continuous operation of >1,000 hours.
Advanced Electrochemical Impedance Analysis Using Distribution of Relaxation Times for in Operando Mechanistic Insights of Fuel Cell and Water Electrolyzer Designs
Authors: Giesbrecht Patrick K , Freund Michael S 
Published: November 2022

The development of sustainable and carbon-neutral alternative energy frameworks and chemical feedstocks requires rapid production of scalable water electrolyzer designs for hydrogen production.[1] Coupling electrolyzers to renewable energy supplies can provide a ‘green’ hydrogen production pathway, enabling clean production of chemical feedstocks as well as an energy storage framework. Current acid-based electrolyzer designs, however, integrate precious metals for stable operation, where drastic reductions in iridium use and increased cell durability are required for scalable deployment.[2] This requires the ability to monitor changes to the cell in operando for rapid diagnostics during initial and long-term operation under sustained or intermittent profiles. One technique proposed is electrochemical impedance spectroscopy (EIS), which can provide a breakdown of the cell resistances based on the timescale of the process.[3] Further analysis by circuit modeling, however, requires significant insight into the system for accurate interpretations. By coupling conventional EIS methods with distribution of relaxation times (DRT) analysis, the number of processes impacting cell operation can be determined without a priori knowledge of the system.[4] This has improved circuit modeling analysis of Li-ion batteries and solid oxide fuel cells.[5] Here, we demonstrate the power of EIS-coupled DRT analysis by analyzing the operation porous cathode and anode films of Nafion-based electrolyzer cells in half-cell and full cell configuration. Analysis of the electrodes in half-cell configurations provides estimates of kinetic parameters, active area, ionic conductivity, and diffusion coefficients associated with the electrode from a single EIS spectrum that are comparable to values obtained from in situ values.[6] Further analysis of the full cell operation with variable cathode gas composition provides insight as to the effect of the cathode gas composition on both the cathode and anode operation and stability. The work presented here will show the versatility and limitations of DRT-coupled EIS analysis of novel fuel cell and electrolyzer designs as well as present key findings for improving electrolyzer performance and stability.
[1]Ayers, K. et al. Annu. Rev. Chem. Biomolec. Eng.
2019, 10, 219-239.
[2]Pham, C. et al Adv. Energy Mater.
2021, 11, 2101998.
[3]Liu, H. et al. J. Phys. Chem. Lett.
2022, 13, 6520-6531.
[4]Wan, T. et al. Electrochimica Acta
2015, 184, 483-499.
[5]Dierickx, S., Ivers-Tiffee, E. Electrochimica Acta
2020,
355, 136764.
[6]Giesbrecht, P.K., Freund, M.S. J. Phys. Chem. C
2022, 126, 132-150.
Modeling Mechanical Behavior of Membranes in Proton Exchange Membrane Water Electrolysis
Authors: Kink Julian , Ise Martin , Bensmann Boris , Hanke-Rauschenbach Richard 
Published: November 2022

The reliability of a proton exchange membrane water electrolysis (PEMWE) depends significantly on the long-term mechanical stability of the membrane due to its relatively low mechanical robustness. Membrane defects can be caused, for example, by severe mechanical stress in the critical gap between the cell frame and the porous transport layer (PTL). In this work the mechanical stresses and strains are quantified for such scenarios by using a finite element (FE) analysis which is applied to a simplified model setup.
Nafion® is used as a standard material for the membrane and an appropriate material model is implemented into a FE software. The used parameters are based on and validated by experimental data from tensile tests to ensure matching with real PEMWE systems. The validated material model is used in the cell simulation to identify resulting stresses and strains during assembly and operation. In accordance with experimental experience, no critical states were identified. Furthermore, differential pressure up to 10 bar in the model could not cause any significant change compared to deformations resulting from boundary conditions for balanced pressure operation. Varying the gap size between the cell frame and PTL resulted in a buckling in the simulated membrane for sizes of 0.3 mm and more during membrane swelling.
(Digital Presentation) Reactive Magnetron Sputtering Deposition of La1.6Nd0.4NiO4 Coating As Cathode for Solid Oxide Fuel Cell
Authors: Ye Xiaolei , Luo Huan , Fourcade Sébastien , Mauvy Fabrice , Bertrand Pierre , Briois Pascal 
Published: November 2022

Ln2NiO4 (Ln=La, Pr, Nd, etc.) materials with K2NiF4 structures are interesting materials for intermediate temperature solid oxide fuel cell (IT-SOFC) due to Mixed Ionic and Electronic Conductivity (MIEC) [1-2]. The present work is focused on the elaboration of La1.6Nd0.4NiO4 coating obtained by Reaction Magnetron Sputtering (RMS). This compound is a promising oxygen electrode able to decrease the operating temperature of SOFC. After a presentation of the deposition operating conditions for obtaining the films, the structural and microstructural characterizations of the coatings were, respectively, determined by XRD and SEM. The electrical properties were studied as a function of temperature by the 4-probe method. Electrochemical properties were investigated in a symmetrical cell electrode / YSZ / electrode by complex impedance spectroscopy. Finally, a complete cell composed of a commercial anode, and YSZ electrolyte made by RMS and the cathode of this study was tested under hydrogen and air in single SOFC cell configuration.
It appeared that the films are amorphous when processed and that they crystallize after an annealing treatment under air. According to this study, a correlation between crystalline structure, morphology and electrical properties will be presented and its last ones are completed by a thermogravimetry analysis.
(Digital Presentation) Fuel Cell Electrode Design - Using a Specially-Modified Force Tensiometer for Gas Bubble Adhesive Force Measurements on Nanostructured Copper Electrodes Submerged in a Liquid
Authors: Fidler Bob , Schaubach Sebastian 
Published: November 2022

Direct liquid-feed fuel cells (DLFCs) have gained attention because of their low-cost, high power densities and clean energy. They have a bright future for both mobile and
stationary applications. DLFCs directly convert chemical energy into electrical energy by the oxidization of liquid fuels. Numerous nanostructured catalysts on the electrodes have been explored to improve the energy conversion efficiency. However, the behavior of the gas products (such as N2 and CO2) on the electrode surfaces received very little attention, which is critical to achieve better performance of the DLFCs especially at high reaction rates. The reason for this is that gas bubbles that accumulate on the surface will not only block the catalyst sites but also cause high pressure in the liquid flow area limiting the fuel crossover. It has been reported that the surface architecture can significantly affect the gas bubble adhesion behavior.
In this work, adhesive forces of the gas bubbles on planar and nanostructured films were measured. Using a force tensiometer outfitted with a video camera and software, adhesion force of the gas bubble on a flat Cu foil was measured. Adhesive forces and submerged liquid contact angle measurements of gas bubbles on planar and nanostructured Cu films are possible. Adhesive forces of liquids in air phase or of gas bubbles under liquid phase can also be analyzed. The special force tensiometer system with video upgrade combines a force measurement to determine the force of adhesion and an optical system to determine the area of contact between the liquid/gas and solid phase for each force that is measured. In such a way, force per area can be determined. The measurement procedure involves a liquid or gas bubble being pushed onto a solid substrate under air or liquid and then pulled off.
(Invited, Digital Presentation) Remembering George Blasse
Authors: Meijerink Andries 
Published: November 2022

The impressive career of George Blasse in the field of luminescence started in 1964. Triggered by the discovery of YVO4:Eu3+ as red phosphor in cathode ray color TVs the management of Philips Research decided to re-establish the luminescence group and George Blasse was asked to lead the group. Very productive years followed in which George discovered many new phosphors, including YAG:Ce3+. In 1970 he made an unusual career switch and accepted the position of professor of Solid State Chemistry at Utrecht University. George Blasse led a highly successful research group for over 25 years and became internationally recognized for his research on luminescent materials. During his career he frequently attended ECS Meetings which has been and continues to be a place where reseaerchers from universities and industry in the field of luminescence materials meet and new phosphors and concepts are presented. I vividly remember attending the ECS meeting in Chicago in 1988 together with George.
George Blasse combined groundbreaking fundamental discoveries with societal relevance. He had a deep and also intuitive understanding of luminescence phenomena and often relied on clever chemical variations in host composition and structure to obtain insight in the underlying physics. Simple guidelines and clear design rules based on systematic and careful research of a wide variety of materials were discovered, explaining spectral variations and trends, for example in thermal quenching of luminescence for Eu3+. The constant energy difference between fd states of different lanthanides was pioneered by George Blasse and later became the basis for the now widely used Dorenbos model. Another area where the work of George Blasse was instrumental involved energy transfer and energy migration phenomena. He was able to translate the somewhat complex theoretical papers as those by Förster and Dexter into simple models and equations to understand and quantify energy transfer processes. George Blasse also made important contributions in understanding of the optical properties of s2 ions like Pb2+, Bi3+, Sb3+ and Sn2+. In recent years this work of George receives increasing attention in the light of extensive work on luminescence of these ions in double perovskites. In this presentation I will share memories and highlight the great contributions of George Blasse to our field.

Figure 1