bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalt Nanoparticles Supported Graphitic Carbon Nitride Electrocatalyst for Oxygen Reduction
Authors: Zabielaite Ausrine , Balciunaite Aldona , Upskuviene Daina , Vaiciuniene Jurate , Jasulaitiene Vitalija , Tamasauskaite-Tamasiunaite Loreta , Norkus Eugenijus 
Published: July 2022

This study is focused on the fabrication of cobalt nanoparticles supported graphitic carbon nitride (CoNPs-g-C3N4) by microwave synthesis and their application for oxygen reduction reaction (ORR). X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) were employed to characterize the prepared catalysts. The electrocatalytic activity of CoNPs-g-C3N4 for ORR was investigated using the rotating disk electrode technique in 0.1 M KOH solution.
It has been determined that the g-C3N4, prepared by annealing melamine at a temperature of 520 oC for two h, had a high nitrogen content of 67.92 at.%. The data of the oxygen reduction on the CoNPs-g-C3N4 catalysts with different Co loadings and under various conditions are presented. Compared to the metal-free g-C3N4, the doping of g-C3N4 with CoNPs enhances the electrocatalytic activity and the selectivity towards the 4e- reduction reaction of O2 to H2O.
Acknowledgment
This project has received funding from European Social Fund (project No. 09.3.3-LMT-K-712-23-0188) under a grant agreement with the Research Council of Lithuania (LMTLT).
Electrocatalytic Activity of Platinum-Nickel Layers Deposited on Nickel Foam for Formic Acid Oxidation in Acidic and Alkaline Media
Authors: Nacys Antanas , Simkunaite Dijana , Sebeka Benjaminas , Upskuviene Daina , Balciunaite Aldona , Zabielaite Ausrine , Jasulaitiene Vitalija , Tamasiunaite Loreta , Norkus Eugenijus 
Published: July 2022

The performance of direct formic acid fuel cells (DFAFCs) is greatly determined by the catalyst materials. Pt nanoparticles-based heterogeneous structures are among the most important substances for the oxidation of formic acid (FAO). In this study, Ni foam catalyst layered with platinum has been investigated as the catalyst for the oxidation of FAO in acidic and alkaline media. The catalyst has been fabricated via a two-step procedure involving the electroless deposition of the Ni layer using sodium hypophosphite as a reducing agent and subsequent electrodeposition of the platinum layer. In this work, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, and X-ray Diffraction have been used to characterize the morphology, structure, and composition of the prepared catalysts. The electrochemical behavior of the bare Pt, Ni/Ni foam, and PtNi/Ni foam electrodes towards the oxidation of formic acid in acidic and alkaline media was evaluated using cyclic voltammetry.
It was found that the PtNi/Ni foam catalyst has a significantly higher electrochemically active surface area of Pt equal to ca. 71 cm2 than pure Pt. Moreover, the PtNi/Ni foam catalyst shows an enhanced electrocatalytic activity towards the FAO via direct pathway in both acidic and alkaline medium compared to those of Ni/Ni and pure Pt electrodes. Furthermore, the prepared PtNi/Ni foam catalyst exhibits greater tolerance of CO than the single-metal Pt in acid solution. Concomitantly, the PtNi/Ni foam catalyst is tolerant to CO poisoning n alkaline media demonstrating high poison removal ability. The PtNi/Ni foam catalyst seems to be a promising future anode material for DFAFCs.
(Digital Presentation) Oxygen Reduction Activity, Durability and Structural Transformation of Pt-Ni Nanowires in the Presence and Absence of Pt-Ni Nanoparticles
Authors: Kato Masaru , Iguchi Yoshimi , Kato Yuta , Li Tianchi , Zhuang Yu , Yagi Ichizo 
Published: July 2022

Carbon-supported Pt-M (M=Ni or Co) nanoparticles (NPs) have been intensively studied as oxygen reduction reaction (ORR) catalysts for the cathode of polymer electrolyte fuel cells. Under electrocatalytic conditions, these catalysts are known to degrade involving particle detachment, agglomeration and metal dissolution. To develop highly durable ORR electrocatalysts, these phenomena can be suppressed by strong metal/support interactions[1,2] or even utilized as self-healing or sacrificial processes.
We present the ORR activity, durability and structural transformation of carbon-supported Pt-Ni nanowires (NWs) in the presence and absence of NPs.[3] In the presence of NPs, NPs were dissolved, and NWs were converted to form branched nanostructures during potential cycles. Because the similar structural transformation of NWs occurred even in the absence of NPs, the structural transformation is an intrinsic phenomenon during potential cycles. Interestingly, the ORR activity increased and the Pt dissolution was suppressed during potential cycles in the co-presence of Pt-Ni NWs and NPs. The electronic and surface structures are also changed before and after potential cycles and will be discussed based on physicochemical measurements including in situ Pt L
3-edge X-ray absorption spectroscopy.
This work was supported by NEDO.
References
[1] M. Kato, K. Ogura, S. Nakagawa, S. Tokuda, K. Takahashi, T. Nakamura, I. Yagi, ACS Omega, 3, 9052–9059 (2018).
[2] M. Kato, R. Nakahoshiba, K. Ogura, S. Tokuda, S. Yasuda, K. Higashi, T. Uruga, Y. Uemura, I. Yagi, ACS Appl. Energy Mater., 3, 6768-6774 (2020).
[3] M. Kato, Y. Iguchi, T. Li, Y. Kato, Y. Zhuang, K. Higashi, T. Uruga, T. Saida, K. Miyabayashi, I. Yagi, ACS Catal., 12, 259-264 (2022).
(Invited) Photoelectrochemical Glycerol Oxidation to Value-Added Commodity Chemicals Using BiVO4-Based Photoanodes
Authors: Hilbrands Adam , Choi Kyoung-Shin 
Published: July 2022

To create a functional photoelectrochemical cell (PEC) for solar fuels production, a cathode and anode reaction must both be chosen and optimized. In order to generate clean energy, a renewable resource such as water, nitrogen, or biomass, is typically reduced at the photocathode to generate H2, ammonia, or carbon-based fuel. In aqueous media, the anode reaction is typically water oxidation, as water is renewable and available in the cell. However, the product of water oxidation, O2, is not very valuable. As such, in recent years attention has been directed to finding a more attractive oxidation reaction that forms a value-added product that can be paired with reduction reactions of interest. Ideally, this reaction would consist of renewable, abundant, and affordable feedstock, such as biomass, that can be readily oxidized to a more valuable compound.
The photoelectrochemical oxidation of glycerol to value-added commodity chemicals fits these criteria. Glycerol is the main byproduct of biodiesel production, and as such is cheap and abundant. As investment in clean fuels increases, the production of biodiesel will continue to increase, leading to an overabundance of glycerol, which can create storage and environmental issues. Developing systems to valorize glycerol will ensure sustainable biodiesel production and advance the transition to renewable fuels. Glycerol consists of three alcohol groups, and many oxidation pathways are possible, with the most profitable being the selective oxidation of the secondary alcohol to a ketone to make dihydroxyacetone (DHA). This conversion yields an over 200-fold value increase from $0.66 to $150 per kilogram. Thus, photoelectrochemical DHA production can provide an opportunity to make PEC operation more profitable while improving the sustainability of the biodiesel industry.
BiVO4 is a good candidate for photoelectrochemical glycerol oxidation as it has a favorable band gap (2.4eV), excellent charge separation, and low water oxidation selectivity. In this presentation, we report our recent results obtained for photoelectrochemical glycerol oxidation using a BiVO4 photoanode. We will discuss various surface modifications of BiVO4 that we employed to elucidate the reaction mechanisms and to maximize the efficiency and selectivity for DHA production.
(Invited) Dye-Sensitized Photoelectrochemical Cells with Hydrogen-Atom Transfer Co-Catalyst for Oxidative Lignin Decomposition
Authors: Lee Jae-Joon 
Published: July 2022

The lack of selectivity of oxidative-cleavage is one of prime issues for decomposition of lignin, because of the harsh reaction environments, such as high temperature and high pressure, in general. Dye-sensitized photoelectrochemical cells with a homogenous hydrogen-atom transfer co-catalyst with Ruthenium-complex based sensitizer as a photocatalyst (e.g. RuC ((bis-2,2′-bipyridine)(2,2′-bipyridine-4,4′-dicarboxylic acid)Ru(II)) (HAT-DSPEC), was suggested as an alternative and this system exhibited the conversion efficiency of over 90% at 24 hour illumination (AM 1.5G) although these metal-complex based sensitizers, having relatively low values of absorption coefficient, generally are not cost-effective and stable enough.
In this study, for highly stable HAT-DSPEC process, metal complex sensitizer was replaced by organic dye(5-[4-(diphenylamino)phenyl]thiophene-2-cyanoacrylic acid, L1) which has high stability and molar absorption coefficient. Also three kinds of organic nitroxyl mediators (HAT) was used such as 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), 4-Acetamido-TEMPO (ACT) and 9-azabicyclo[3,3,1]nonan-3-one-9-oxyl (Keto-ABNO). Each HATs (TEMPO, ACT and keto-ABNO) showed different reactivity and conversion efficiency (about 65%, 60% and 88%). In HAT-ODSPEC(organic dye-sesitized photo-electrochemical cell), Keto-ABNO showed highest conversion efficiency with 2-ol(S,G). This HAT-ODSPEC process provides a unique foundation to perform selective C−C bond cleavage for real lignin conversion technologies.
Single-Atom Photocatalysis: Surface-Defect Engineered TiO2 Anatase As a Tunable Platform for Hosting Co-Catalysts Atoms
Authors: Mohajernia Shiva , Hejazi Sina , Kilian Manuela 
Published: July 2022

Single‐atom (SA) or single‐site catalysis (SACs) has over the past years become an increasingly fascinating topic in the catalysis field. SACs have allowed new approaches in heterogeneous catalysis, minimized the use of precious metals, and enabled an unprecedented control over atomistic effects, resulting in improved active sites, and at the same time enabled the design of metal–support interfaces with a high level of structural and chemical control [1,2]. A diverse range of supports and features is known to stabilize isolated metal atoms, notably through pinning at electronic and/or structural defects associated with coordinatively unsaturated sites. However, it is still difficult to create a high density of thermally stable support sites, and hence the fabrication and control of high SA loading remains a challenge [1,2].
In this work, an atomic‐scale defect engineering approach to form and control traps for SA sites as co‐catalyst for photocatalytic H2 generation is described. The control over defect types and density can be monitored by electron paramagnetic resonance spectroscopy (EPR) as the most precise method to study atomic scale defects [3]. Thin sputtered TiO2 layers are used as a model photocatalyst, and compared to the more frequently used (001) anatase sheets. To form stable SA co-catalysts, the TiO2 layers are reduced in Ar/H2 under different conditions (leading to different but defined Ti3+‐Ov surface defects), followed by immersion in a dilute solution containing Pt ion in this study. HAADF‐STEM results show that only on the thin‐film substrate can the density of SA sites be successfully controlled by the degree of reduction by annealing. An optimized SA‐Pt decoration can enhance the normalized photocatalytic activity of a TiO2 sputtered sample by a great extent in comparison to a conventional nanoparticle‐decorated TiO2 surface. Most interestingly, in the follow up work based on DFT calculations and experimental data we show that Pd single atom outperforms Pt as the most active co-catalyst for photocatalytic H2 evolution [4]. HAADF‐STEM, XPS, and EPR investigation jointly confirm the atomic nature of the decorated Pt and Pd on TiO2. Importantly, the density of the relevant surface exposed defect centers—thus the density of SA sites, which play the key role in photocatalytic activity—can be precisely optimized.
[1] Sh. Mohajernia et al. Adv. Mater. 2020, 32 (16).
[2] A. Wang, J. Li, and T. Zhang, Nat. Rev. Chem., 2(6).
[3] Sh. Mohajernia et al. J. Mater. Chem. A, 2020, 8(1432)
[4] G. Cha et al. iScience, 2021, 8 (24).

Figure 1
Operando Studies on High-Temperature CO2 Electrolysis to Fuels
Authors: Kamboj Vipin , Ranjan Chinmoy 
Published: July 2022

High temperature CO2 electroreduction of one of the most promising technologies for converting CO2 to fuels. Electroreduction can typically result in various reduced products but interms of energy efficiency a electrolytic reduction to CO followed by Fischer Tropsch (along with H2) based conversion to hydrocarbon fuels is most preferred. Nickel-Yttria Stabilized Zirconia cermet (Ni/YSZ) is one of the most common electrodes used in solid oxide fuel cells. Lately, various groups have essentially repurposed the same electrode for CO2 electrolysis. However, it suffers from catalyst degradation and poor activity.
Successful operation of these electrodes requires presence of H2 in the CO2 stream. In presence of hydrogen CO2 undergoes reverere water gas shift reaction leading to production of CO (non electrochemically) in combination with electrochemical water splitting. Using operando Raman and online Mass Spectroscopy we have followed the evolution of catalyst from preatreatment in various atmospheres to its performance under conditions of operation.
The mentioned electrodes were operated at current densities between 100-400 mA/cm2. The operando studies show that Ni active sites oxidize to NiOx in the presence of pure CO2. The poor electronic conductivity of NiO adversely affects the activity of the electrode. The failure is rather drastic at higher current densities. Apart from this, mass spectroscopy confirmed the formation of coke during CO2 electrolysis through Bouduard reaction. The absence of any Raman signal for carbon indicated that the reaction only proceeds to a small extent and the primary deactivation occurs through oxidation of Ni.
Small amounts of H2 (~5%) in the mixture prevented the deactivation, but the reaction seemed to proceed through Reverse Water Gas Shift reaction followed by Water electrolysis. Furthermore, we have explored the performance of Ni(Mx)/YSZ type cathodes for CO2 reduction. The electrode performances were compared using three electrode configuration based measurements. Our results indicate that catalysts development in situ is drastically different for mixed metal oxides often resulting in different type of spatial distribution of the metals compared to the pure Ni/YSZ. Many electrodes show promising behavior in terms of both enhanced activity and catalyst stability.

Figure 1
(Invited) Modeling the Defect Chemistry, Transport Properties, and Stability of Anti-Perovskite Materials
Authors: Ciucci Francesco 
Published: July 2022

Solid-state electrolytes with fast lithium conduction are the core of the all-solid-state Li-battery technology. By substituting the organic electrolyte with a piece of non-flammable ceramic material, we can achieve better safety, higher specific capacity, and a higher energy density. To date, the major bottleneck for this technology is the slow Li diffusion in the solid-state electrolyte and the interfacial incompatibility between the electrolyte and electrodes. To resolve these issues, several families of fast ionic conductors have been developed. Understanding Li diffusion in these materials is essential to the development of novel family fast ionic conductors. To this end, atomistic modeling provides us with a unique tool to obtain comprehensive information on atom motion, which is difficult to access with experimental techniques. In this talk, we showcase our group’s atomistic simulations regarding a novel family of superionic conductors, Li-rich antiperovskites (LiRAPs)
LiRAPs are a promising family of solid electrolytes, which exhibit ionic conductivities above 1 mS/cm at room temperature, among the highest reported values to date. Here, we report on the defect chemistry and the associated lithium transport in Li3OCl, a prototypical LiRAP, using DFT calculations and classical MD simulations [1]. We studied these materials’ phase, interfacial, and voltage stability [2,3] with DFT, showing good agreement with experiments, further proposing low-dimensional superionic antiperovskites [3]. In addition, the interfacial properties were studied for both protonated and fluorinated materials [4]. Analogous simulations were also carried out for Na-rich antiperovskites [5].

Acknowledgments

Support from the Research Grants Council of Hong Kong is gratefully acknowledged.

References

[1] Z Lu, C Chen, ZM Baiyee, X Chen, C Niu, F Ciucci. Defect chemistry and lithium transport in Li3OCl antiperovskite superionic conductors. Physical Chemistry Chemical Physics 17 (48), 32547-32555 (2015)
[2] Z Lu, F Ciucci. Antiperovskite cathodes for lithium batteries. Journal of Material Chemistry A, 6, 5185-5192 (2018)
[3] Z Lu, J Liu, F Ciucci. Superionic conduction in low-dimensional-networked antiperovskites. Energy Storage Materials, 28, 146-152 (2020)
[4] M Effat, J Liu, Z Lu, TH Wan, and F Ciucci. Stability, elastic properties, and the Li transport mechanism of the protonated and fluorinated antiperovskite lithium conductors. ACS Applied Materials and Interfaces, 12, 49, 55011-55022 (2020)
[5] TH Wan, Z Lu, F Ciucci. A first principle study of the phase stability, ion transport and substitution strategy for highly ionic conductive sodium antiperovskite as a solid electrolyte for sodium ion batteries. Journal of Power Sources, 390, 61-70 (2018)
(Invited) Ion Conduction and Interface Stability of Sulfide Based Solid State Electrolytes – an Atomistic Perspective
Authors: Banerjee Soumik , Dive Aniruddha Mukund 
Published: July 2022

All-solid-state batteries are promising in terms of safety as well as high energy density compared to the conventional organic liquid-based lithium batteries. However, the characteristic low ionic conductivity of solid-state electrolytes is a major challenge towards commercialization of solid-state sodium ion batteries. Sulfide-based electrolytes especially in amorphous form have been reported as promising solid electrolytes owing to their relatively high ionic conductivity at room temperature. However, a fundamental understanding of the local structure of these amorphous electrolytes and its subsequent impact on the ion transport could be instrumental in establishing guidelines for designing novel solid electrolytes. In the present work, we utilize first principles and classical atomistic simulations to characterize the local structure and investigate the ion transport in amorphous sulfide electrolytes. We selected sodium thiosilicate [xNa2S – (1-x) SiS2] and sodium thiophosphate [xNa2S – (1-x) P2S5] based electrolytes as a model system wherein we characterized the local structure, ion conduction mechanism and ultimately calculated the ionic conductivity of these electrolytes. We utilized experimental X-ray and neutron scattering data for model validation. Our theoretical calculations provide fundamental insights into ion conduction mechanisms as well as correlate ionic conductivity with electrolyte structure and composition.
Along with ionic conductivity, interfacial stability is extremely important factor influencing the overall performance of solid-state batteries. Interfacial instability with sulfide electrolytes is detrimental to Li-ion transport, leading to poor cycling performance. Inherent thermodynamic instability of sulfide-based solid electrolytes drives the chemical reaction across the interface leading to formation of undesired secondary phases. The secondary phases are formed dynamically during the cycling and therefore a careful investigation into the dynamics at the electrolyte-cathode interfaces is crucial. To generate fundamental understanding of the interface stability, we utilized ab initio molecular dynamics (AIMD) simulations to carefully investigate the dynamics of secondary phase formation across the Li3PS4 | LiCoO2 interfaces. High-resolution microscopy and spectroscopy studies were used to complement the the first principles simulations methods and unravel the interphases formed under different cycling conditions. These calculations provide crucial insights into formation of secondary phases across the interface, which could be leveraged to evaluate possible avenues to inhibit formation of such undesirable secondary phases.
Planar Anode Supported SOFC Fabricated By Sequential Aqueous Tape Casting, Constrained Cosintering and Screen-Printing
Authors: Parvaix Laura , Lenormand Pascal , Quéré Damien , Rozier Patrick 
Published: July 2022

Hydrogen technologies and especially fuel cells, are promising alternatives to achieve a carbon-free energy and an ecofriendly transition [1]. The SOFC technology (Solid Oxide Fuel Cell) is an energy conversion system composed of a stack of a porous cathode, a dense electrolyte and a porous anode working at a temperature in the [600°C – 1000°C] range to obtain ionic conductivity above 10-2 S/cm.
Nowadays, tape-casting is typically used for mass and low-cost manufacturing of supporting half-cell (8YSZ electrolyte and Ni-YSZ anode) and the cathode layer is commonly deposited by screen-printing [2]. In line with the cost reduction problematic, this presentation will describe the development and optimization of a green sequential tape casting process to obtain the anodic half-cell and screen-printing for the cathode. To target green process, aqueous based slurries are used and only non-toxic organic components are selected. The amount of organic components, ceramic powder and water was optimized to obtain slurries with a shear-thinning behavior while managing the powder dispersion stability. The parameters of the drying heat treatment have been optimized based on Thermal Gravimetric Analysis leading to obtain a multilayer flexible green tape without any bubbles or cracks further annealed to eliminate the organics and co-sinter the stack under a porous YSZ load. The flat anodic half-cell with a thin and dense layer of 8YSZ on a thick and porous layer of NiO-YSZ is completed by screen-printing of La2NiO4+
δ (cathode) based ink followed by a consolidation thermal treatment. The characterization using X-ray diffraction, scanning electron microscopy and operando electrochemical tests of the cell allow validating the efficiency of the sequential tape-casting to fabricate via environmentally friendly process and low cost SOFC.
[1] Rissman, J. et al. (2020) ‘Technologies and policies to decarbonize global industry: Review and assessment of mitigation drivers through 2070’, Applied Energy, 266, p. 114848. doi:10.1016/j.apenergy.2020.114848.
[2] Udomsilp, D. et al. (2021) ‘Performance Benchmark of Planar Solid Oxide Cells Based on Material Development and Design.’, Energy Technology, 9. doi:10.1002/ente.202001062.