bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition Metal Doped Cannabis Catalysts for the Oxygen Reduction Reaction in Hydrogen Fuel Cells
Authors: Rana Zahra Imran , Feng Jingyu , Magliocca Emanuele , McAlernon Patricia , Miller Thomas Samuel , Titirici Magda , Brett Dan 
Published: July 2022

The global climate crisis demands a rapid uptake of alternatives to fossil fuels to alleviate further damage to the planet. To this end, supercapacitors, batteries and fuel cells have been identified as critical enabling technologies to overhaul the current energy system. As the demand for these energy storage and conversion devices increases, so does the need to produce sustainable, low-cost and high-performing components for them.
Currently, platinum is used to catalyse the sluggish oxygen reduction reaction (ORR) in hydrogen fuel cells. It is generally deposited on a carbon support and forms an electrode that is vital in determining electrochemical performance (namely activity and durability); however, this presents a two-pronged challenge. Traditionally, the carbon used is synthesised via energy-intensive and time-consuming processes involving the incomplete combustion of heavy petroleum products or coal. Secondly, platinum scarcity lends to issues of high cost, which is often ascribed to being the largest hindrance in large-scale commercialisation of this technology. To mitigate these issues, an electrocatalyst based on transition metals and a biomass precursor can be effectively used instead.1

A very promising biomass precursor is hemp. Also known as industrial hemp, it is one of two strains of the cannabis plant. It is one of the oldest domesticated crops in the world, known for its sustainability, high yield and ability to grow on marginal land with low water and pesticide requirements. It is carbon-negative, low-cost and biodegradable - making it the ideal choice in the current climate crisis. Through thermal carbonisation and activation, it yields 3-dimensional hierarchical structures with high conductivity, surface area and porosity.2

Here we report on using nitrogen, iron and cobalt together with cannabis-derived carbon to produce a high functioning and low-cost electrocatalyst to replace Pt/C at the cathode, as shown by a suite of characterisation and electrochemical techniques. With a uniform mesoporous texture and good distribution of metal species, the material displays properties beneficial to catalysing the ORR with a much lower environmental and monetary cost than traditional Pt/C. This forms an excellent basis for further work in this field to achieve the overarching goals of high performance coupled with environmental sustainability.

Borghei M., Lehtonen J., Liu L. and Rojas O. J. 2018 Advanced Biomass-Derived Electrocatalysts for the Oxygen Reduction Reaction. Adv. Mater.
30 1703691

Rana Z. I., Shah A. R., Llewellyn A. V., Mazloomian K., McAlernon P., Miller T. S., Cullen P. L., Shearing P.R. and Brett D. J. L. B. 2022 A new high: Cannabis as a budding source of carbon-based materials for electrochemical power sources. Curr. Opin. Electrochem.
31 100860
Large-Scale Synthesis of Photocatalytic TiO2 Nanotube Layers
Authors: Sopha Hanna , Baudys Michal , Krysa Josef , Macak Jan M. 
Published: July 2022

Self-organized TiO2 nanotube layers have attracted considerable scientific and technological interest over the past 15 years motivated for their wide range of applications including (photo-) catalysis, hydrogen generation and biomedical uses [1,2]. The synthesis of the 1D TiO2 nanotube layers is carried out by a conventional electrochemical anodization of valve Ti metal sheets in various electrolytes.
By now, the synthesis of TiO2 nanotube layers with different nanotube dimensions (diameter, length) and the application of these nanotube layers is well established on the laboratory scale. However, for real applications outside the laboratory scale, such as photocatalysis [3], TiO2 nanotube layers of much larger size are necessary. To date, just a few efforts were carried out to scale up the size of the nanotube layers to more than a few cm2 [3-7] due to the difficulty of controlling the parameters of the anodization process on a larger scale. The main challenge is the huge current received during the anodization of large substrates. This, in turn, leads to an increase in the electrolyte temperature that may result in dielectric breakdown of the growing nanotube layers.
In this presentation, the preparation of TiO2 nanotube layers on larger area titanium substrates (dozens of cm2) will be discussed, taking into account the control of the anodization parameters. The TiO2 nanotube layers with different thicknesses and nanotube diameters were employed for gas phase photocatalysis, following the ISO standards [3,8]. Experimental details and photocatalytic results will be presented and discussed.
References
[1] J.M. Macak, H. Tsuchiya, A. Ghicov, K. Yasuda, R. Hahn, S. Bauer, P. Schmuki, Curr. Opin. Solid State Mater., 11 (2007) 3.
[2] K. Lee, A. Mazare, P. Schmuki, Chem. Rev., 114 (2014) 9385.
[3] H. Sopha, M. Baudys, M. Krbal, R. Zazpe, J. Prikryl, J. Krysa, J.M. Macak, Electrochem. Commun., 97 (2018) 91.
[4] S. Franz, D. Perego, O. Marchese, M. Bestetti, J. Water Chem. Tech., 37 (2015) 108.
[5] H.-I. Kim, D. Kim, W. Kim, Y.-C. Ha, S.-J. Sim, S. Kim, W. Choi, Appl. Catal. A: Gen., 521 (2016) 174.
[6] J.P. Ghosh, G. Achari, C.H. Langford, Water Environ. Res., 88 (2016) 785.
[7] C. Xiang, L. Sun, Y. Wang, G. Wang, X. Zhao, S. Zhang, J. Phys. Chem. C 121 (2017) 15448.
[8] H.Sopha, M. Baudys, J. Krýsa, J. M. Macak, Ms in preparation.
Intrinsic Cu Nanoparticle Decoration of TiO2 Nanotubes: A Platform for Efficient Noble Metal Free Photocatalytic H2 Production
Authors: Hejazi Sina , Mohajernia Shiva , Kilian Manuela 
Published: July 2022

The use of titanium dioxide (TiO2) for photocatalytic applications has been intensively investigated for years due to appropriate electronic properties, chemical and photocorrosion resistance, as well as the low cost of the material [1]. Although TiO2 has a suitable conduction band position for the photocatalytic H2 formation reaction, the hydrogen evolution reaction from water on a TiO2 surface is kinetically hampered. To tackle this problem, typically decoration with noble metals such as Pt, Pd, Au that act as a co-catalyst is employed. However, these noble metals are costly and a variety of pathways for replacing these elements have been explored. One of the promising substitutes for noble metals are copper and copper-compounds. The fabrication of copper co-catalyst loaded TiO2 nanotubes is conventionally carried out by chemical methods such as hydrothermal, impregnation, photo-deposition and electrochemical deposition [2]. However, a most straightforward and unique method to modify anodic TiO2 nanotube properties is employing, instead of pure Ti metallic substrate, a Ti‐X alloy in the anodization process, were X is another metal. During anodizing the second metal can be simultaneously oxidized and doped into the TiO2 lattice (in substitutional or interstitial position), giving the nanotubes a specific functionality [3–5]. A number of such intrinsically doped nanotube arrays have been reported, namely using Nb, Ta, Ru and etc., alloyed in Ti [3–5].
In this work, we grow intrinsically Cu doped TiO2 nanotubes (TiNTs) by self-organizing anodization of Ti-Cu binary alloys. We demonstrate that up to a copper concentration of 1.5 at.% in the alloy, self-ordered Cu2+-doped nanotubes can be grown. Under UV illumination the Cu2+ ion-doped oxide structures can be converted to nanotubes that carry metallic nanoparticles (NPs) uniformly decorated TiNTs. We investigate the formation of these metallic nanoparticles under UV illumination by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). The resulting intrinsic copper doped and decorated TiNTs provide a strongly enhanced photocatalytic activity for H2 evolution in comparison to pristine TiNTs. Key is the light induced conversion of the intrinsic Cu doping to metallic copper nanoparticles that act as a stable co-catalyst for H2 generation.
[1] K. Lee, A. Mazare, P. Schmuki, Chem. Rev.
2014, 114, 9385–9454.
[2] M. Janczarek, E. Kowalska, Catalysts.
2017,
7, 317-324.
[3] P. Roy, C. Das, K. Lee, R. Hahn, T. Ruff, M. Moll, P. Schmuki, J. Am. Chem. Soc.
2011,
133, 5629–5631.
[4] M. Altomare, K. Lee, M.S. Killian, E. Selli, P. Schmuki, Chem. - A Eur. J.
2013, 19, 5841–5844.
[5] C. Das, P. Roy, M. Yang, H. Jha, P. Schmuki, Nanoscale. 2011, 3, 3094–3096.

Figure 1
(Invited, Digital Presentation) Photo-Electrochemical Water and CO2 Reduction Devices Operating Under Concentrated Radiation
Authors: Haussener Sophia , Patel Mahendra , Boutin Etienne 
Published: July 2022

Achieving high current densities while maintaining a high energy conversion efficiency is one of the main challenges for enhancing the economic competitiveness of solar fuel producing photo-electrochemical devices [1]. I will discuss two device implementations utilizing concentrated irradiation to achieve high current density operation. The water-splitting device is utilizing thermal integration to sustain high performance while dealing with high current density and the corresponding overpotentials [2]. I will quantify the theoretical increase in the maximum efficiencies at given current densities of photoelectrochemical devices resulting from thermal synergies. I will then discuss device implementation of such an approach and show how more realistic device models (multi-dimensional, multi-scale, multi-physics) can be used to support the device implementation and its operational understanding [3]. I will then show how the design principles developed for water splitting can be translated to CO2 reduction devices and discuss a corresponding device implementation.
[1] M. Dumortier, S. Tembhurne, S. Haussener, Energy Environmental Science, 8: 3614-3628, 2015.
[2] S. Tembhurne, F. Nandjou, S. Haussener, Nature Energy, 4: 399-407, 2019.
[3] S. Tembhurne, S. Haussener, Journal of The Electrochemical Society, 163: H1008-H1018, 2016.
Capping-Ligand Density on Cu Nanoparticles Determining Multi-Carbon Product Selectivity in Electrochemical CO2 Reduction
Authors: Oh Yusik , Byon Hye Ryung 
Published: July 2022

Carbon dioxide (CO2) emission from the combustion of fossil fuel causes global warming and climate change. Much attention has been paid for recycling of CO2 gas, namely converting this greenhouse gas to high-value fuels such as multi-carbon products (ethylene, ethanol, propanol, etc.). In particular, electrochemical CO2 reduction reaction (CO2RR) is one of the promising methods operated at ambient pressure and room temperature. By using gold and silver catalysts, carbon monoxide (CO) is successfully yielded with >80% Faradaic efficiency. In contrast, it is still challenging to produce multi-carbon (i.e., C2+) products. Copper (Cu) is known as the sole catalyst to yield C2+ products by affording the suitable binding energy to the intermediate of *CO (the asterisk denotes the surface adsorption). Although various synthetic methods for the preparation of Cu nanoparticles (NPs) have been developed to increase the surface area and design of the preferred facets for the CO2 reduction, the highly sensitive Cu surface in air and from contaminants resulted in variable Faradaic efficiencies for C2+ production. In particular, the capping ligands, which coat the Cu surface to stabilize the designed nanostructures, should significantly influence the catalytic efficiency and stability. However, their effects have been little studied.
Here, we show the enhanced catalytic activity and stability of Cu NPs for the C2+ yield by eliminating the capping ligands.[1] The pristine Cu NPs with ~8 nm of diameter were prepared by using a capping ligand of tetradecylphosphonate (TDP). After UV-ozone treatment, the TDP ligands were eliminated in part; The phosphorous signal was attenuated, and the Cu surface was oxidized in X-ray photoelectron spectra. In addition, the carbonyl oxygen (O=C) emerged from the damaged TDP. In contrast, the carbon substrate and the surface roughness of the Cu were insignificantly changed. These UV-ozone-treated Cu NPs showed ~50% Faradaic efficiency of the C2+ conversion (FEC2+) at –0.98 V vs. RHE, which was twice as high as that of the pristine Cu NPs (~25%). In particular, the FEC2+ gradually increased as the remaining capping ligands were removed, indicating the increased catalytic sites for 3 h CO2RR. In sharp contrast, the FEC2+ from the pristine Cu NPs was consistently low despite the partial stripping of the capping ligands, suggesting the negligible formation of the C2+ active sites. For prolonged chronoamperometry tests for 20 h, these FEC2+ values were retained for both catalysts, while the size and shape of Cu catalysts were differently changed. The UV-ozone-treated ones proceeded little agglomeration and contained many grain boundaries. In contrast, the pristine Cu NPs were transformed to the cubic particles with ~100 nm size. The distinct alternations of Cu structures are closely related to the yield of the C2+ active sites, which I will discuss in this presentation.
[1] J. Mater. Chem. A, 9, 11210 (2021)

Figure 1
(Digital Presentation) Electrochemical-Mechanical Coupling between Single-Ion Conducting Electrolytes and Metal Electrodes
Authors: Carmona Eric A , Song Yueming , Albertus Paul 
Published: July 2022

Solid-state metal batteries provide increased gravimetric and volumetric energy density compared to conventional Li-ion batteries and their development is essential for meeting performance and cost targets for consumer applications. Conventional liquid electrolytes exhibit reactivity with pure Li and undergo significant dendrite formation, thus single-ion conducting solid electrolytes have been explored to prevent and mitigate dendrite formation as they possess high modulus, high room temperature ionic conductivity, and the potential to improve safety compared to organic liquid electrolytes. Unfortunately, ceramic single-ion conducting electrolytes such as LLZO have been demonstrated to form dendrites above critical current densities. Understanding the electrochemical-mechanical coupling between the electrolyte and electrode can help elucidate the mechanisms of dendrite formation and propagation in solid-state metal batteries as well as methods for prevention and mitigation. Mechanical stresses arise during battery operation due to external stack pressure, expansion and contraction of intercalation electrodes, and the deposition and stripping of metal electrodes. As we demonstrated in a previous work1, the thermodynamic state of the electrode is affected by its mechanical state, therefore, applied stresses alter the equilibrium potential of metal electrodes. Additionally, the mechanical state of the electrode can influence the metal electrode plating and stripping kinetics. Previous studies in the literature have examined the effect of mechanics on the current distribution; however, careful attention is required when coupling electrochemistry and mechanics as well as consideration as to the importance of the mechanical state of the electrolyte. This talk will focus on the effects of mechanical stresses on the current distribution at the metal electrode/single-ion conducting electrolyte interface and the implications on dendrite formation and mitigation.
References:
(1) Carmona, E. A.; Wang, M. J.; Song, Y.; Sakamoto, J.; Albertus, P. The Effect of Mechanical State on the Equilibrium Potential of Alkali Metal/Ceramic Single-Ion Conductor Systems. Advanced Energy Materials
2021, 11 (29), 2101355. https://doi.org/10.1002/AENM.202101355.
Investigation of the Hydrogen Mass Fraction Distribution in a Polymer Electrolyte Fuel Cell through Experimentally Validated Simulation
Authors: Bodner Merit , Penga Željko , Hacker Viktor 
Published: July 2022

During the start-up of a fuel cell, but also during transient operation, the availability of hydrogen at any location of the active surface of the fuel cell anode is crucial for its safe and reliable operation. When neglecting water vapor, inlet hydrogen mass fractions below one may occur when inert gases or air are flushed out during start-up or as a result of nitrogen accumulation due to fuel recirculation in fuel-efficiency driven system operation [1], [2]. Therefore, in a combined experimental and simulation-based approach, the hydrogen mass fraction distribution over the active area of a 25 cm2 single cell was investigated and the impact of it on known degradation mechanisms such as the corrosion of carbon-based anode catalyst support was determined through off-gas analysis. With a new approach to time-resolved computational fluid dynamic simulation (based on an existing model by Penga et al. [3]) the progression of local conditions during current ramp up were visualized [4].
References
[1] B. Wang, H. Deng, and K. Jiao, “Purge strategy optimization of proton exchange membrane fuel cell with anode recirculation,” Appl. Energy, vol. 225, no. May, pp. 1–13, 2018, doi: 10.1016/j.apenergy.2018.04.058.
[2] K. Kocher, S. Kolar, W. Ladreiter, and V. Hacker, “Cold start behavior and freeze characteristics of a polymer electrolyte membrane fuel cell,” Fuel Cells, vol. 21, no. 4, pp. 363–372, 2021, doi: 10.1002/fuce.202000106.
[3] Ž. Penga, C. Bergbreiter, F. Barbir, and J. Scholta, “Numerical and experimental analysis of liquid water distribution in PEM fuel cells,” Energy Convers. Manag., vol. 189, pp. 167–183, Jun. 2019, doi: 10.1016/j.enconman.2019.03.082.
[4] M. Bodner, Ž. Penga, W. Ladreiter, M. Heidinger, and V. Hacker, “Simulation-Assisted Determination of the Start-Up Time of a Polymer Electrolyte Fuel Cell,” Energies, vol. 14, no. 23, p. 7929, Nov. 2021, doi: 10.3390/en14237929.
(Invited, Digital Presentation) Infiltrated Electrodes for High Temperature Energy Conversion, Electrolysis, and Chemical Synthesis
Authors: Tucker Mike C , Hu Boxun , Welander Martha M , Shen Fengyu , Lau Grace Y. 
Published: July 2022

Solid oxide cell (SOC) infiltrated electrodes typically consist of a ceramic or cermet porous scaffold with the pore walls coated with catalyst particles. The pore size of the scaffold is 1 to 50 mm, whereas the catalyst particles are 10 to 300 nm. This scaffold provides a stable and durable mechanical structure, and the fine catalyst particles provide high surface area for electrochemical and heterogeneous reactions. The scaffold is sintered and bonded to the other layers of the complete cell. After this high temperature processing is finished, catalyst precursor solution is flooded into the scaffold and fired at moderate temperature to form the desired catalyst composition and phase. Because the scaffold is sintered in the absence of catalysts, re-optimization of the fabrication process, ink formulation, deposition process, and sintering protocol is not needed when a new catalyst is introduced to the cell design. Instead, a new precursor solution can be prepared from a stoichiometric mixture of metal salts, with minimal change in processing. This approach makes it straightforward to screen many catalyst compositions in a short period of time, and adapt an existing cell structure for a wide variety of applications.
The Lawrence Berkeley National Laboratory metal-supported solid oxide cell (MS-SOC) design has a thin electrode scaffold of zirconia ceramic co-sintered on a thick porous stainless steel support layer. Both layers are coated with infiltrated catalysts. The catalyst precursor solution is an aqueous mixture of metal nitrate salts. After the solution is flooded into the pores of the scaffold, it is dried and heated in air to convert the nitrate salts to mixed metal oxides. The oxides can then be reduced to metals by firing in reducing atmosphere, if desired. The drying rate, heating rate, conversion temperature, and other processing parameters can have a dramatic impact on the catalyst particle morphology and ultimately on the performance and durability of the electrochemical device.
Depending on the choice of catalyst composition, the MS-SOCs can be configured as fuel cells, electrolysis cells, or chemical conversion reactors. Several examples will be highlighted, including: fuel cell operation with hydrogen, ethanol, and natural gas; steam electrolysis for hydrogen production; and oxidative coupling of methane for valuable chemical synthesis. In each case, technical progress will be presented with a focus on catalyst development and device performance.

Figure 1
Impacts of Manifold Geometry and Flow Configuration on Shunt Current, Current Distributions, and Crossover in an Alkaline Electrolysis Stack
Authors: Lopata Joseph Steven , Kang Sanggyu , Cho Hyun-Seok , Kim Chang-Hee , Shimpalee Sirivatch 
Published: July 2022

Alkaline diaphragm water electrolysis (ADWE) devices have undergone widespread commercialization for about a century to date. Their high resistance relative to polymer electrolyte cells has motivated the employment of ion exchange membranes. However, recent advancements in the zero-gap configuration, in which porous electrodes are in contact with the porous ZrO2/polysulfone diaphragm, hold promise in extending the use of this inexpensive and durable technology by eliminating a portion of resistive losses.
Desired improvements to the technology include reductions in electrode void fraction, crossover, and shunt current. Lower void fractions increase current density by allowing aqueous ions to both migrate and react at a greater portion of the electrode surface. The geometry investigated utilizes a design in which electrolyte feed is injected from the manifolds directly into the porous electrode without an intermediary flow field, which promotes product gas expulsion 1. Crossover is of particular concern because it puts a lower constraint on the practical thickness of the porous separator. Different modes of operation are investigated in this work to understand what provokes gas crossover locally, as previously done 1. Shunt current arises whenever an electrolyte solution is fed to a stack containing multiple electrodes contacted in series, inducing potential gradients in the electrolyte and leading to ion migration. This can lead to local potential gradients in the manifolds that allow undesired corrosion of the current collectors to occur.
This three-dimensional (3-D) computational fluid dynamics model of an ADWE stack of five cells in series aims to gather details of the aforementioned problems, notably how they vary in 3-D space. Void fractions and crossover are compared between simulations of co- and counter-current operation. The locations of potential gradients that threaten the lifespan of the system are identified, and this information is used to suggest strategies to reduce or mitigate high void fraction, high local crossover, and high potential gradients in manifolds. Additionally, as this is a stack model, through-plane current distributions and notes on the fluid flow rates from cell to cell are provided.
References

J. S. Lopata, S-G. Kang, H-S. Cho, C-H. Kim, J. W. Weidner, S. Shimpalee, Electrochim. Acta, 390, 138802 (2021).

Figure 1