bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Understanding the Electrocatalytic Mechanisms of Oxygen and Carbon Dioxide Reduction Reactions
Authors: Liu Di-Jia 
Published: July 2022

Oxygen reduction reaction (ORR) is one of the most important reactions in the field of electrocatalysis today. ORR represents a key cathodic reaction in hydrogen fuel cell, which typically needs to be promoted by the platinum group metals (PGMs), particularly Pt. The high cost of Pt adds significant barrier to the widespread implementation of the fuel cell technology. During the last two decades, substantially amount of effort has been invested in searching for low-cost replacements, or PGM-free catalysts for ORR. Although significant progress has been made, such catalysts still face major challenge in durability. By adding small amount of Pt over PGM-free catalytic substrate, we have found that both activity and stability will be significantly improved through synergistic interaction. [1] To better define synergistic effect in ORR catalysis, however, requires a carefully designed experiment that can separates multiple factors during the catalyst synthesis that can potentially influence the overall activity. In this report, we will discuss our recent study in understanding of the ORR catalysis synergy between Pt/PGM-free components in rationally designed catalyst systems.
Another fast developing area of electrocatalysis is CO2 reduction reaction (CO2RR), which promises to electrochemically convert CO2 to fuels and chemicals using renewable electricity. While CO2RR via 2-electron transfer, such as the conversion to CO or formate, has been proven high selective with fast kinetics, conversions to C2+ chemicals require significantly stronger binding between the catalytic site and CO2 to complete multiple electron transfers (8 to 16) and C-C bond coupling steps, therefore are more challenging. More recently, we develop a new amalgamated lithium metal (ALM) synthesis method to preparing highly selective and active CO2RR catalyst for C2+ chemicals such as ethanol production. [2] In this presentation, we will discuss the hypothesis driven CO2RR catalyst design, combined with the mechanistic study for preparing effective catalysts. We will also share some critical insight on CO2RR mechanism through advanced structural characterization and computational modelling.

Acknowledgement: This work is supported by U. S. Department of Energy, Hydrogen and Fuel Cell Technologies Office through Office of Energy Efficiency and Renewable Energy and by Office of Science, U.S. Department of Energy under Contract DE-AC02-06CH11357.
[1] L. Chong, J. Wen, J. Kubal, F. G. Sen, J. Zou, J. Greeley, M. Chan, H. Barkholtz, W. Ding, and D.-J. Liu, “Ultralow-loading Platinum-Cobalt Fuel Cell Catalysts Derived from Imidazolate Frameworks,” Science (2018) 362, 1276
[2] “Highly selective electrocatalytic CO2 reduction to ethanol by metallic clusters dynamically formed from atomically dispersed copper” Haiping Xu, Dominic Rebollar, Haiying He, Lina Chong, Yuzi Liu, Cong Liu, Cheng-Jun Sun, Tao Li, John V. Muntean, Randall E. Winans, Di-Jia Liu and Tao Xu, (2020) Nature Energy, 5, 623–632
Performance Prediction of Alkaline Fuel Cell Via Gradient Boosting Algorithm
Authors: Park Jihyeon , Lee Jaeyoung 
Published: July 2022

With the DFT theory at the forefront, non-PGM catalysts have begun to develop, and in much literature, results have shown that the performance of non-PGM catalysts is comparable to that of PGM catalysts. Jing et. al. synthesized Fe-Co dual sites on nitrogen-doped carbon for oxygen reduction reaction (ORR). (FeCo)/N-C had almost equal half-wave potential to commercial Pt/C.[1] Hanguang et. al. achieved high ORR-activated Fe-N-C catalysts by tuning the doped Fe content and active sites.[2] However, if both (FeCo)/N-C and Fe-N-C were applied to PEMFC, they were not comparable to PGM catalysts unlike in the results of the half-cell test. This discrepancy means that numerous factors should be considered and optimized in a practical system like a fuel cell. Besides, it is indicated that even if the DFT theory and deep-learning combine to suggest catalysts with high performance, it may not produce as much performance in the actual fuel cell system as expected.
In this respect, the combination of fuel cell systems (not catalysts) and artificial intelligence (AI) seems more reasonable. Without human judgment or intervention, machine learning sets priorities between each index by learning from many databases.
Herein, we newly developed an optimization model for alkaline liquid fuel cell (Hydrazine fuel cell) using gradient boosting algorithm (XGBoost) which is one of machine learning algorithms. We operated fuel cells in various conditions by changing humidity of cathode, back pressure of cathode, cell temperature, stoichiometric factor (air/fuel), and concentration of the fuel. And then, we categorized and classified with the specific algorithm. Finally, we re-organized and set as a function of weight which effects on fuel cell operation. We hope that these approach will help improve fuel cell performance by controlling a number of factors without human intervention.
[1] J. Wang, Z. Huang, W. Liu, C. Chang, H. Tang, Z. Li, W. Chen, C. Jia, T. Yao, S. Wei, Y. Wu, Y. Li, J. Am. Chem. Soc. 139 (2017) 17281–17284.
[2] H. Zhang, H.T. Chung, D.A. Cullen, S. Wagner, U.I. Kramm, K.L. More, P. Zelenay, G. Wu, Energy Environ. Sci. 12 (2019) 2548–2558.
Lignin-Based N-Doped Nanocarbons for the ORR
Authors: Kaare Kätlin , Kruusenberg Ivar , Volperts Aleksandrs , Dobele Galina , Zhurinsh Aivars 
Published: July 2022

Fuel cells (FC) are one of the most viable energy conversion devices that could replace fossil-fuel based energy production in the future. As the oxygen reduction reaction (ORR) happening at the cathode side has slow kinetics, the usage of catalysts that speed up the process is inevitable. Most of the studied catalyst materials include precious metals or their alloys. Lately, the conversion of biomass to carbon nanomaterials and the usage of biomass-based carbons in different energy conversion systems has grown enormously [1].
Lignin among the major components of lignocellulosic biomass, which is mainly produced in the pulp and paper industry or in biorefineries. To fully unlock the potential of biorefineries, the components of lignocellulosic biomass (e.g. lignin, hemicellulose, cellulose) must be fractionated and valorized [2]. Currently, lignin is used to produce electricity and heat in factories or landfilled. Since the main component of lignin is carbon, it is possible to synthesize lignin-based carbon nanomaterials.
In this work, lignin from a local Estonian biorefinery was used to produce high specific surface area nanocarbons that were studied as catalysts for the ORR. Different ways (two-step or one-step) and temperatures (700 or 800 °C) were used to carry out the carbonization and activation processes. In the second step, dicyandiamide was used to carry out the nitrogen doping at 800 °C. Electrochemical characterization of the N-doped industrial lignin-based carbon catalysts were carried out by employing rotating disc electrode method. We show that a simultaneous carbonization and activation process in the presence of NaOH is the most effective towards creating the best catalyst precursor for the ORR, as the lignin-derived nanocarbon shows higher electrochemical activity towards the ORR than commercial N-doped graphene (Fig 1).

References

[1] J. Deng, M. Li, Y. Wang, Green Chem. 18 (2016) 4824–4854.
[2] D.S. Bajwa, G. Pourhashem, A.H. Ullah, S.G. Bajwa, Ind. Crops Prod. 139 (2019) 111526.

Figure 1
(Invited, Digital Presentation) Design, Preparation and Characterization of Photofunctional Materials Based on Energy-Resolved Distribution of Electron Traps
Authors: Ohtani Bunsho 
Published: July 2022

How can we design functional solid materials, such as catalysts and photocatalysts? What is the decisive structural parameters controlling their activities, performance or properties? What is obtained as structural properties by popular conventional analytical methods, such as X-ray diffraction (XRD) or nitrogen-adsorption measurement, is limited to bulk crystalline structure and specific surface area, i.e., no structural characterization on amorphous phases, if present, and surface structure has been made so far. This is because there have been no macroscopic analytical methods to give surface structural information including possibly-present amorphous phases. Recently, we have developed reversed double-beam photoacoustic spectroscopy (RDB-PAS) which enables measure energy-resolved distribution of electron traps (ERDT) for semiconducting materials such as metal oxides [1,2]. Those detected electron traps (ETs) seem to be predominantly located on the surface for almost all the metal oxide particles, and therefore they reflect macroscopic surface structure, including amorphous phases, in ERDT patterns. Using an ERDT pattern with the data of CB bottom position (CBB), i.e., an ERDT/CBB pattern, it has been shown that metal oxide powders, and the other semiconducting materials such as carbon nitride, can be identified without using the other analytical data such as XRD patterns or specific surface area, and similarity/differentness of a pair of metal-oxide samples can be quantitatively evaluated as degree of coincidence of ERDT/CBB patterns. In this talk, an approach of material design based on the ERDT/CBB-pattern analyses is introduced [3].
[1] Nitta, A.; Takase, M.; Takashima, M.; Murakami, N.; Ohtani, B. A Fingerprint of Metal-oxide Powders: Energy-resolved Distribution of Electron Traps. Chem. Commun.
2016, 52, 12096-12099. [2] Nitta, A.; Takashima, M.; Murakami, N.; Takase, M.; Ohtani, B. Reversed double-beam photoacoustic spectroscopy of metal-oxide powders for estimation of their energy-resolved distribution of electron traps and electronic-band structure. Electrochim. Acta
2018, 264, 83-90. [3] Nitta, A.; Takashima, M.; Takase, M.; Ohtani, B. Identification and characterization of titania photocatalyst powders using their energy-resolved distribution of electron traps as a fingerprint. Catal. Today
2019, 321-322, 2-8.
Photoanode Interface and Surface Treatment Effect in Dye-Sensitized Photo Electrochemical Systems on Oxidative Cleavage of Lignin
Authors: Kang Hyeong Cheol , Kim Saerona , Yoo Kicheon , Leem Gyu , Lee Jae-Joon 
Published: July 2022

Traditionally, Dye-sensitized photo electrochemical cells (DSPECs) have been targeted for solar-driven water splitting as production of fuels in aqueous media. Recently, hydrogen atom transfer incorporated dye-sensitized photo electrochemical cell (HAT-DSPEC) which used photocatalyst and homogeneous catalysts incorporating system was suggested for the decomposition process of lignin. This HAT-DSPEC system representing conversion efficiencies over 90% resulted in the formation of the oxidized ketone product from model compounds under simulated solar illumination with an applied bias 0.4 V vs Ag/Ag+
for 24 hrs. However, they have several issues such as long reaction time, low stability and high bias potential.
To overcome these problems, in this study, dye-sensitized photovoltaics’ advanced technic is applied. In HAT-DSPEC system, photo-anode (TiO2@Dye) has important role to produce oxoammonium species by oxidizing HAT mediator. And these oxidized HAT do a catalytic reaction with target materials: lignin model compounds (LMCs). However, in photo-anode, lots of charge recombination and electron back transfer occurs on the FTO and TiO2 surface. So, for effectively producing oxoammonium species from photoelectrode, using blocking layer to passivate FTO surface from electrolytes and applying TiCl4 post-treatment enhances charge transport in TiO2. The photocurrent response of the m-TiO2@Ru470 photoelectrode in a nonaqueous electrolyte was examined with increasing mediators concentration during light on/off cycles under AM 1.5G illumination (100 mW/cm−2), with an applied bias 0.4 V vs Ag/Ag+. Comparing three kinds of condition such as m-TiO2, BL/m-TiO2, BL/m-TiO2/TiCl4 post treatment, showed a significant increase in maximum photocurrent up to approximately 49.3, 101.3, 231.6 μA/cm−2 with 5 mM NHPI/2,6-Lutidine mediator. This result indicates that the blocking layer and TiCl4 post treatment enhanced electron life time and collection efficiency in the photoelectrode, as well as enhancing the capability of producing oxoammonium species.
Large Non-Classical Electrostriction in Aliovalent and Isovalent Doped Ceria
Authors: Varenik Maxim , Wachtel Ellen , Ehre David , Gaver Elad , Lubomirsky Igor 
Published: July 2022

The majority of commonly used electrostrictive ceramics are based on lead manganese niobate. These ceramics display large electrostriction strain coefficients ≈ 10-16 m2/V2 at frequencies up to a few kHz. However, they suffer from major drawbacks: they require high driving currents (dielectric constant >10000), contain toxic elements, and are incompatible with thin film Si-microfabrication techniques.
We have recently reported that ceria ceramics doped with aliovalent cations having crystal radii smaller than that of cerium, display increased high frequency (f >100Hz) longitudinal electrostriction strain coefficients |M|. For instance, with 10 mol% Lu3+ or Yb3+ lanthanide dopants, |M| ~ 10-17 m2/V2 is observed for f >100Hz . Despite Yceria ~200GPa and eceria ~ , these electrostriction strain coefficients are 100-fold larger than estimated on the basis of Newnham’s scaling law for “classical” electrostrictors. Such “non-classical” behavior has been attributed to the formation of highly polarizable, elastic dipoles reorienting under external electric field.
Surprisingly, doping with small isovalent dopants, such as Zr and Hf , produces an increase in |M| to , independent of frequency up to several kHz, as determined by converse electrostriction measurements. The introduction of Zr raises the dielectric constant more than predicted by the Clausius-Mossotti relation. This suggests that the presence of a small dopant creates a highly polarizable unit which may be responsible for the large electrostriction strain coefficient. Our results demonstrate that, by systematically adjusting the composition of ceria-based solid solutions, the possibility exists for development of technologically useful electrostrictive materials which are, at the same time, ecologically sound and fully compatible with Si-microfabrication.
(Invited) Mesoscale Reaction Kinetics Modulated By Structural and Compositional Heterogeneity in Battery Cathode Materials
Authors: Liu Yijin 
Published: July 2022

Doping, coating, and particle engineering for cathode materials are broadly adopted by both academia and industry to improve the battery performance. The lack of an in-depth understanding for the underlying mechanism, however, makes it a largely try-and-error process with unsatisfactory efficiency and effectiveness. This is particularly true for the electrochemical reaction kinetics that is heterogeneous over a broad range of length scales and is determined collectively by the cathode’s electronic structure, lattice configuration, and micro-morphology.
In this presentation, I will talk about the use of advanced synchrotron techniques for imaging the cathode particles with structural, chemical and compositional sensitivities. We will talk about the mutual modulation between the surface chemistry and the bulk charge distribution and mechanical cracking. As an example, we will discuss how a facet-dependent dopant segregation in Zr-modified single-crystal LiNi0.6Co0.2Mn0.2O2 cathode would modulate its mesoscale reaction kinetics. This study suggests that a delicately controlled dopant distribution is a viable strategy for designing the next-generation battery cathode with superior structural and chemical robustness.
(Invited) The Stability and Kinetics of the Li/Solid Electrolyte Interface
Authors: Sakamoto Jeff 
Published: July 2022

Owing to the potential to achieve >1000 Wh/L and >400 Wh/kg while exhibiting a dramatic improvement in safety, Li-metal solid-state batteries (SSBs) are promising technology to accelerate the widespread adoption of EVs. However, their remain gaps in knowledge in understanding the mechanical and electrochemical phenomena that control the stability and kinetics of the Li/solid electrolyte (SE) interface.
It is well known that Li (and Na) can penetrate ceramic and polymer solid electrolytes during charging. The term critical current density (CCD) is frequently used to determine the maximum charging rate before Li filaments penetrate. When normalized to a flat planar interface, CCDs during plating in literature range between 0.1 and 10 mA/cm2. Indeed, there is a broad range CCDs upon charging, moreover the role of pore formation during stripping has shed light on the factors that contribute Li metal penetration. In addition, factors can affect CCD such as charge passed (0.01 to 3 mAh/cm2), temperature (25 to 200 oC), pressure (0 to tens of MPa), and Li thickness (0.1 to 750 microns).
In this presentation, the aspects that collectively contribute to determining the stability and kinetics of the Li/SE will be discussed. The discussion with shift the recent focus on Li penetration during charging to Li void formation at the interface during stripping in cells that use commercially relevant Li thickness (< 20 microns), “anode-free” or in-situ formed Li anodes, LLZO SE. The results of this work can help guide efforts develop Li metal SSB for use in EVs.
Professor Jeff Sakamoto has 20 years of experience studying and translating ceramic materials for electrochemical materials into energy technologies for terrestrial and space applications. He was a senior researcher at the Caltech Jet Propulsion Laboratory (2000-2007), a Professor at Michigan State University (2007-2014), and has been a Professor at the University of Michigan since 2014. The Sakamoto group synthesizes ceramic electrolytes, tests their electrochemical and mechanical properties, and develops manufacturing processes for solid state batteries. Dr. Sakamoto is a Kavli Frontiers of Science Fellow, and was a chair, organizer, speaker, and delegate at the National Academy of Sciences Frontiers of Science and the National Academy of Engineering Frontiers of Engineering Symposia. Dr. Sakamoto received two Major Space Act Awards from the NASA Inventions and Contributions Board, is the primary contributor on 34 patents and received the Teacher-Scholar (2013), and Withrow Excellence in Teaching (2009) Awards at Michigan State University.
(Invited) Developing Barrier Layer Free Oxygen Electrode for Solid Oxide Cells
Authors: Zhang Yongliang , Tang Qiming , Huang Kevin 
Published: July 2022

High temperature solid oxide cell (SOC) technology is attracting considerable interest in recent decades for clean power generation and hydrogen production (green hydrogen) when combined with low-cost renewable energy. The key driver for such a strong interest is its superior thermodynamic efficiency and high-rate power and hydrogen production. However, the current scale-up and commercialization efforts are hindered by the insufficient durability and high cost, both of which are resulted from the high operating temperature (700-800oC). A further reduction in operation temperature to, e.g. below 700oC, is the best solution to address the durability and cost issues. As the operating temperature is reduced, the resistances of cell components increase correspondingly. To decrease the resistances, one can thin out or use high-conductivity electrolyte membranes, open up microstructure of fuel (or hydrogen) electrodes substrate and employ oxygen electrocatalytically active oxygen electrodes. Unfortunately, a direct use of active oxygen electrodes in SOCs has been proven formidable due to their reaction with electrolytes (ZrO2-based) and very high thermal expansion coefficient. To address the first problem, applying a CeO2-based barrier layer between electrolytes and oxygen electrodes is currently the solution. However, introduction of such a barrier layer considerably increases the ohmic resistance (sometimes as high as 2-3x), thus defeating the purpose of boosting cell performance. To address the second problem, mixing the active oxygen electrode with CeO2-based material or infiltrating it into a thermally compatible skeleton is currently the solution, but CeO2-based barrier layer is still needed.
Therefore, a key development for reduced-temperature ZrO2-based SOCs is to find an active oxygen electrode without the need of a barrier layer. Here we show that a composite consisting of La0.8Sr0.2MnO3 (LSM), an excellent electronic conductor, and (Bi0.75Y0.25)0.93Ce0.07O1.5±δ (BYC), an excellent ionic conductor, is a potential barrier layer free oxygen electrode for reduced-temperature SOCs. We also show fabrication of open structured hydrogen electrode substrate to facilitate H2/H2O diffusion and increase the performance of HE.
(Invited) Membrane Coated Electrocatalysts for Selective and Stable Oxygen Evolution in Seawater
Authors: Baxter Amanda F. , Fraga Alvarez Daniela V. , Kuvar Dhruti , Esposito Daniel V. 
Published: July 2022

Seawater electrolysis has the potential to be a more sustainable means of hydrogen production compared to conventional water electrolysis which relies on highly pure water. This is particularly true for arid coastal regions with access to seawater and ideal conditions for harvesting solar and wind energy, but where fresh water is already scarce.[1] Seawater electrolysis is challenging due to the large concentration of chloride ions, which can be detrimental to electrocatalyst stability. Furthermore, the presence of chloride ions allows the chlorine evolution reaction (CER) to compete with the oxygen evolution reaction (OER) at the anode. Although Cl2 is of industrial value, global hydrogen production already exceeds chlorine production, and demand for hydrogen is projected to grow more rapidly. Additionally, since Cl2 is toxic and harmful to the environment, implementing seawater electrolysis is simplified if pure oxygen is produced and can be safely vented to the atmosphere.
Our group has shown that ultrathin semi permeable oxide overlayers can be designed to selectively transport reactants to the active catalyst at the buried interface.[2-3] Importantly for seawater electrolysis, the oxide overlayer selectively rejected chloride ions while allowing for water transport.[4] Thus, the oxide overlayer acts as a membrane, and the composite material can be referred to as a membrane coated electrocatalyst (MCEC). An additional advantage of the MCEC architecture compared to conventional electrocatalysts is enhanced stability.[5] This makes MCECs particularly attractive for stable and selective OER in seawater. This work describes how MCECs can (i) improve catalyst stability and (ii) enable selectivity for OER over CER by impeding transport of chloride ions to the catalyst at the buried interface. This work explores the fundamental relationships between chloride ion transport through different oxide overlayer materials. This knowledge is then applied to prepare MCECs supported on high surface area porous electrodes.

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