bluuebunny/crossref_metadata_2025_split huggingface dataset:
What Is Needed for Industrial Carbon-Dioxide Electroreduction: From Electrode Development to Process Optimization
Authors: Janaky Csaba 
Published: February 2024

Electrochemical reduction of CO2 is a promising method for converting a greenhouse gas into value-added products, utilizing renewable energy. Novel catalysts, electrode assemblies, and cell configurations are all necessary to achieve economically appealing performance. In this talk, I am going to present a zero gap electrolyzer cell, which converts gas phase CO2 to products without the need for any liquid catholyte. This is the first report of a CO2 electrolyzer cell, where multiple cells are connected into a stack, thus scaling up the electrolysis process. I will show how proper cell components and operational conditions result in unprecedentedly high partial current densities in zero-gap cells. I will demonstrate the role of each component of the membrane electrode assembly, such as the catalysts, the porous transport layers, the membrane, and the ionomers.
In the second part of my talk, I will show that while precipitate formation in the cathode gas diffusion electrode is detrimental for the long-term stability, the presence of alkali metal cations at the cathode improves performance. To overcome this contradiction, I will present different approaches which help to extend the lifetime of the electrolyzer cell. As an outlook, I will present a complex machine learning based approach, through which we aim to find the optimal operating conditions of such CO2 electrolyzer cells.
References:

Janáky et. al.: Multilayer Electrolyzer Stack Converts Carbon Dioxide to Gas Products at High Pressure with High Efficiency, ACS Energy Letters 4 (2019) 1770-1777

Janáky et. al.:High carbonate ion conductance of PiperION membrane allows industrial current density and conversion in zero-gap carbon dioxide electrolyzer cell Energy & Environ. Science, 13 (2020) 4098-4105

Janáky et. al. : Operando cathode activation with alkali metal cations allows high current density operation of water-fed zero-gap carbon dioxide electrolyzers, Nature Energy, 6, (2021) 439–448

Janáky et. al.: Coupling electrochemical CO2 conversion with value-added anode processes: an emerging paradigm, Current Opinion in Electrochemistry, 25 (2021) 100621

Janáky et. al.:Local Chemical Environment Governs Anode Processes in CO2 Electrolyzers ACS Energy Letters, 6 (2021) 3801-3808

Janáky et. al.:Systematic screening of gas diffusion layers for high performance CO2 electrolysis, Communications Chemistry, 6 (2023) 41

Janáky et. al.:Membrane Electrode Assembly for Electrocatalytic CO2 Reduction: Principle and Application, Angewandte Chemistry International Edition, in press, DOI: 10.1002/ange.202302789
Low-Cost and Scalable Electrodes for Anodic Production of Hydrogen Peroxide Via 2e- Water Oxidation
Authors: Pangotra Dhananjai , Vieira Luciana , Roth Arne 
Published: February 2024

Hydrogen peroxide (H2O2) is a crucial chemical that is widely utilized in various industrial processes. The conventional anthraquinone process for H2O2 production has limitations in terms of energy consumption, high costs, and waste generation [1]. An alternative, greener and more sustainable approach is the electrochemical production of H2O2 from oxygen and water using renewable energy. Our research group has been extensively investigating the two electron (2e-) water oxidation reaction (WOR) for production of H2O2 using various electrode materials, including metal oxides, commercial carbon materials, and boron-doped diamond (BDD) [2, 3]. We also investigated the role of carbonate ions (HCO3
- and CO3
2-) in the process of water oxidation to H2O2. The enhancing effect e of CO3
2- ions on anodic H2O2 production was studied in a continuous flow reactor, where the optimal flow rate, process configuration and cell design, and chemical stabilizer were determined. Among other parameters, chemical composition and pH regime of the electrolyte were found to be crucial.
Recently, we explored the use of graphite bipolar plates (BPP) as a low-cost alternative to BDD electrodes for anodic H2O2 generation [4]. Three different commercial BPPs with varying fluoropolymer content were examined, and a correlation was found between fluoropolymer content and H2O2 generation. In that study we found that a BPP sample with high fluoropolymer content resulted in a stable H2O2 production for up to 100 hours at a current density of 200 mA cm–2, with a constant faradaic efficiency of 40%. The results demonstrate that low-cost commercial carbon electrode materials can selectively oxidize water to H2O2, enabling economically viable technical applications of anodic H2O2 production.

References

[1] S.C. Perry, D. Pangotra, L. Vieira, L.-I. Csepei, V. Sieber, L. Wang, C. Ponce de León, F.C. Walsh, Electrochemical synthesis of hydrogen peroxide from water and oxygen, Nature Reviews Chemistry, 3 (2019) 442-458.
[2] D. Pangotra, L.-I. Csepei, A. Roth, C. Ponce de León, V. Sieber, L. Vieira, Anodic production of hydrogen peroxide using commercial carbon materials, Applied Catalysis B: Environmental, 303 (2022) 120848.
[3] D. Pangotra, L.-I. Csepei, A. Roth, V. Sieber, L. Vieira, Anodic generation of hydrogen peroxide in continuous flow, Green Chemistry, 24 (2022) 7931-7940.
[4] D. Pangotra, A. Roth, V. Sieber, L. Vieira, Electrochemical Water Oxidation to Hydrogen Peroxide on Bipolar Plates, ACS Sustainable Chemistry & Engineering, 11 (2023) 2680-2685.
Zincate Replacement, an Economical a Sustainable Alternative for the Metal-Coating of Aluminum
Authors: Walter Anke , Tomin Bogdan , Kohlmann Lars , Krause Carsten , Brunner Heiko 
Published: February 2024

Aluminum parts are of great value for many industries as they are cost-effective, very lightweight combined with a good mechanical strength. However, when parts are exposed to corrosive and abrasive conditions it is preferred to protect them with anodizing, powder coating, or for technical critical applications with nickel-phosphorus (NiP) coatings. Most preferred for functional parts such as scroll compressors, connectors,... is electroless NiP (EN) as it is has a low thickness variation in the final deposit and does not need the application of current like galvanic NiP coatings.
Depositing an adherent layer of electroless NiP onto aluminum needs an alloy-specific pre-treatment. The largest challenge in pre-treatment lies in the very fast formation of Al2O3 oxide under neutral pH conditions of 4 - 9. For decades a very effective way to inhibit the re-oxidation of aluminum is the use of alkaline zinc as interim coatings that dissolve in the electroless NiP electrolyte before NiP deposition starts. Commercial solutions are optimized to produce an as thin and homogenous as possible zinc deposit to minimize the drag-in of zinc into the NiP electrolyte. At levels of 80 - 200 mg/l zinc starts to lower the adhesion and plating rate of deposited EN coatings. As results the nickel process needs to be discarded before nickel deposition capacity of electrolyte is fully reached (~ 40 g/l plated Ni). The impact of Zn contamination is most critical as lower the thickness of the EN layer is. At very thin thicknesses below 4 µm the increase of zinc is very large, and electrolytes need to be discarded at 6-12 g/l plated nickel creating higher chemical waste, maintenance effort, and cost. Due to technical changes in many applications, different and more parts will be composed of aluminum. In contrast to established applications NiP that exhibit EN layers > 5 µm new applications arise with the upcoming EV and Battery market that request thinner NiP layers. The most extreme case is reel-to-reel plating of thin (< 50 µm) foils with NiP deposits below 4 µm.
In the present work, the application of a new chemical concept of aluminum pre-treatment for low-thickness EN coatings will be presented that reduces the number of needed process steps compared to double zincate by at least 2 steps (excl. rinses) without the need for special equipment such as pulse plating and others. Differences in the initiation of electroless NiP deposition and the correlated adhesion will be evaluated. As a model case, the application of thin NiP layers (< 4 µm) on pure Aluminum foils will be shown and discussed.

Figure 1
A Scalable Furnace Technique to Grow Silicon Nanoparticles for High-Performance Li-Ion Battery Anodes
Authors: Patil Rohan , Phadatare Manisha , Örtegren Jonas , Hummelgård Magnus , Blomquist Nicklas , Olin Håkan , Limaye Santosh , Bäckström Joakim , Zanghellini Ezio , Brandell Daniel , Hernández Guiomar 
Published: February 2024

Lithium-ion battery (LIB) technology is one of the key technologies to lower the emission from fossil fuel while maintaining stable supply of energy to the society. One way to increase the capacity of LIBs is to add silicon to the graphite anode, since silicon can store much more lithium ions than graphite. Silicon does however expand and contract during lithiation and delithiation, leading to cracks which deteriorates the performance of the LIB anode. Mechanical cracking can be avoided by using sufficiently small silicon nanoparticles. Several high-performance schemes utilizing silicon nano materials such as nanoparticles, nanotubes, nanorods etc. have been demonstrated but industrial-scale implementation of these solutions still poses a challenge. The Siemens process is one of the most commonly used methods to create silicon nanoparticles and uses chemical vapor deposition (CVD) processes involving silane or silane derivatives as precursors. Due to the flammable and toxic nature of silane, the CVD process requires special handling care and expensive instrumentation. In this work, a novel scalable furnace technique to create silicon nanoparticles attached to graphene flakes LIB anode applications is presented. With this technique, we can avoid the silane precursor. In addition, the instrumentation requirements of the furnace technique are quite simple and inexpensive and the technology is compatible with already established industrial-scale electrode manufacturing techniques.
In the work presented here we demonstrate how silicon nanoparticles are grown from micro sized silicon powder onto graphene flakes using simple thermal treatment. Thermal gravitometry, mass spectrometry and differential scanning calorimetry was used to show how silicon powder and a binder can be converted to silicon nanoparticles by simple pyrolysis. The silicon nanoparticles are grown on top of graphene flakes to create a LIB anode. The anode, when tested in a half cell assembly shows a capacity that is considerably higher than standard graphene/graphite electrodes.
Understanding the Self-Discharge Redox Shuttle Mechanism of Dimethyl Terephthalate in Lithium-Ion Batteries
Authors: Bötticher Tom , Adamson Anu , Buchele Sebastian , Alter Ethan D. , Metzger Michael 
Published: February 2024

Recent studies showed that LFP/graphite cells without additives show higher reversible self-discharge after 500 h of open-circuit voltage (OCV) storage at 40 or 60°C than NMC811/graphite cells.1 Furthermore, cells with lithium hexafluorophosphate (LiPF6), the most commonly used conducting salt in lithium-ion batteries, show higher self-discharge than cells with lithium bis(fluorosulfonyl)imide (LiFSI), an alternative salt with higher temperature stability.2 Recently, dimethyl terephthalate (DMT) was identified as the redox shuttle molecule responsible for the unwanted self-discharge of these lithium-ion batteries.3 In a lithium-ion cell, a reversible shuttle can gain an electron at the negative electrode by reduction, diffuse to the positive electrode, lose the electron by oxidation, and then repeat the process many times (see Figure 1). Adamson et al.4 proved that DMT is created in-situ as a breakdown product of polyethylene terephthalate (PET), which is a surprisingly common polymer for the adhesive tapes found in commercial batteries. The exact redox potential and electrochemical stability of DMT, as well as its shuttling mechanism across electrodes passivated with a solid-electrolyte interphase (SEI) however were not understood.
Based on an optimized coin cell cyclic voltammetry setup, ultra high precision coulometry measurements, OCV storage, and GC-MS experiments, we present new insights on the self-discharge redox shuttle mechanism of DMT in LFP/graphite pouch cells, investigate if this redox shuttle can account for the self-discharge differences in LiPF6 and LiFSI cells, and explore the stability of DMT in pouch cells.

References:

E. R. Logan, A. Eldesoky, E. Eastwood, H. Hebecker, C. P. Aiken, M. Metzger and J. R. Dahn, J Electrochem Soc, 2022, 169, 040560.

E. R. Logan, A. Eldesoky, E. Eastwood, H. Hebecker, C. P. Aiken, M. Metzger and J. R. Dahn, J Electrochem Soc, 2022, 169, 040560.

S. Buechele, A. Adamson, A. Eldesoky, T. Boetticher, L. Hartmann, T. Boulanger, S. Azam, M. B. Johnson, T. Taskovic, E. Logan and M. Metzger, J Electrochem Soc, 2023, 170, 010511.

A. Adamson, T. Bötticher, K. Tuul, M. Garayt, S. Azam and M. Metzger, Manuscript in Preparation, 2023.

Figure 1
(Invited) Recent Progress in Redox Flow Deionization
Authors: Kim Choonsoo , Kim Seonghwan 
Published: February 2024

Recently, redox flow deionization (RFD) has gained great interest in water desalination as a promising electrochemical ion separation process. The RFD system advances the redox flow battery by adapting intervening channels for the water stream. As a unique cell feature, the system is comprised of multi-channels allowing the independent control of the flow streams (e.g., water stream and redox flows). This leads to several advantages compared to the conventional electrochemical ion separation processes such as capacitive deionization and electrodialysis: (1) sustainable redox reaction enables low operational cell voltage and high diversity in the employment of electrode materials, (2) the mild reaction environments allow less byproduct production and less variation in pH as this system facilitating downstream processes, and (3) the stored energy at redox couples provides energy recovery process with a simultaneous ion separation leading to high energy efficiency in water desalination.
In line with the development of RFD, this presentation aims to introduce the basic principle of the RFD system and recent progress, including cell architecture, electrodes, operations, and scale-up strategy. In addition, various applications are addressed such as resource recovery and pollutant control. Finally, we briefly propose the practical challenges and opportunities for future research direction.
Gold Recovery from Thiosulfate Leaching Solution Using Silicon Powder and Electrochemical Monitoring of Its Process
Authors: Yae Shinji , Iwai Yuna , Takashima Yumi , Osaka Takumi , Matsumoto Ayumu 
Published: February 2024

Gold recycling from Waste Electrical and Electronic Equipment (WEEE) has been actively conducted. We previously reported a noble metal recovery process using aqua regia and electroless displacement deposition onto silicon powder [1,2]. Using silicon powder has such advantages as that noble metals and copper are selectively recovered, and sawdust silicon, that is, industrial waste silicon powder is available to use. Recently, ammonium thiosulfate solution has attracted attention as a safe and low-cost solution for gold leaching [3-6]. In this study, we successfully recovered gold from an ammonium thiosulfate solution by using silicon powder [7,8], and tried to monitor the recovering behavior electrochemically. Since the ammonium thiosulfate leaching solution includes copper ions as oxidizing agent, copper is recovered by silicon powder. Thus, the monitoring was conducted in order to determine the suitable timing for efficiently obtaining pure gold during the process. For experimentation, an ammonium thiosulfate solution containing gold(I) sulfite and copper(II) sulfate was prepared (pH = 13). We immersed a gold wire in the solution and measured the rest potential during the recovery process using silicon powder. The potential of gold wire shifted stepwise toward negative direction at each start and end of gold and copper recovery. The results suggest that the efficient recovery of high-purity gold can be achieved by monitoring the potential of gold.
[1] K. Fukuda, S. Yae, N. Fukumuro, S. Sakamoto, and H. Matsuda, ECS Trans., 53(19), 69 (2013). DOI: 10.1149/05319.0069ecst
[2] K. Fukuda, N. Fukumuro, S. Sakamoto, and S. Yae, ECS Trans., 61(10), 1 (2014). DOI: 10.1149/06110.0001ecst
[3] M.G. Aylmore and D.M. Muir, Miner. Eng., 14, 135 (2001). DOI: 10.1016/s0892-6875(00)00172-2
[4] H. Arima, T. Fujita, and W. Yen, Mater. Trans., 43, 485 (2002). DOI: 10.2320/matertrans.43.485
[5] S. Syed, Hydrometallurgy, 115-116, 30 (2012). DOI: 10.1016/j.hydromet.2011.12.012
[6] B. Xu, W. Kong, Q. Li, Y. Yang, T. Jiang, and X. Liu, Metals, 7, 222 (2017). DOI: 10.3390/met7060222
[7] Y. Iwai, Y. Takashima, A. Matsumoto, and S. Yae, Abst. Interfinish2020 20th world congress, P-E2-001 (2021).
[8] Y. Takashima, A. Matsumoto, Y. Iwai, S. Arita, and S. Yae, J. Surf. Finish. Jpn., 73, 98 (2022). DOI: 10.4139/sfj.73.98
Electrochemical Reduction of Ytterbium in Non-Aqueous Solvents - Towards Production of Pure Medical Lutetium-177
Authors: Aerts Robin , Geboes Bart , Van Hecke Karen , Binnemans Koen , Cardinaels Thomas 
Published: February 2024

In recent years targeted radionuclide therapy has become a topic of great interest as a growing number of cancers can potentially be treated with radionuclides like lutetium-177 and samarium-153. To facilitate this growth and meet the demand, preparation and purification of lutetium-177 is increasing in importance. In the most common production route, enriched ytterbium-176 targets are irradiated and the produced lutetium-177 is separated from the ytterbium target material. This challenging separation is commonly performed using ion exchange resins, a method limited in scalability as the chemical similarity between ytterbium and lutetium results in poor separation at higher concentrations.
An alternative method to aid the separation of lutetium from ytterbium is the electrochemical reduction of ytterbium as a change in oxidation states changes chemical properties significantly. Ytterbium has an accessible divalent state, whereas lutetium has not. However, the very negative value of the Yb(III)/Yb(II) standard reduction potential (E0= -1.04 V vs. SHE) does pose some challenges as it becomes a necessity to work in non-aqueous solvents with a very low water content. Similar research has already been performed in our group, looking into the separation of samarium-153 from europium-154, reducing europium in nitrate media, followed by a separation over TEVA resin. In this study, we investigated the reduction of ytterbium in ethylene glycol, dimethyl sulfoxide, tetrahydrofuran and N,N-dimethyl formamide by cyclic voltammetry, linear sweep voltammetry and electronic impedance spectroscopy. The influence of multiple variables such as moisture content on the reduction kinetics and stability of Yb(II) was determined and a Koutecky-Levich analysis was performed. Our results demonstrate that the reduction of ytterbium in non-aqueous solvents is feasible but attempts to perform bulk electrolysis were not successful yet. Ethylene glycol, dimethyl sulfoxide and N,N-dimethyl formamide demonstrate favorable conditions and in each solvents clear reduction and oxidation peaks were observed. It was found that the solvents do affect the peak separation, reduction potential and sensitivity to passivation.

Figure 1
Electrochemical Direct Air Capture of Carbon Dioxide by a Redox-Mediated Salt Splitting Process
Authors: George Thomas Young , Mangold Lucie , Wang Cliffton , Schrag Daniel P. , Aziz Michael J. 
Published: February 2024

Direct air capture of carbon dioxide is an important emerging direction for electrochemical separation technology. Carbon dioxide removal has a critical role to play in the coming century as a complement to deep decarbonization efforts, because removal may offset emissions we cannot avoid, such as agriculture for food security. Direct air capture might even be used to decrease the atmospheric carbon dioxide level if the value at which it stabilizes is deemed too high. Electrochemical methods allow us to power a carbon removal device directly by carbon-free electricity. Here, we present a salt splitting process, based on bipolar membrane electrodialysis, which begins with a neutral electrolyte (e.g. KCl), and creates a strong base (e.g., KOH) and a strong acid (e.g., HCl). The base may then be used to absorb carbon dioxide from ambient air; the acid is then used to extract the carbon dioxide by recombining with the base, reversing the salt splitting process. The process is driven by iron(II/III) hexacyanide redox on carbon cloth electrodes, which is kinetically facile and contributes relatively little to the cell voltage.
Energy required for redox-mediated salt splitting depends on contributions from water dissociation in the bipolar membrane, ohmic resistances in ion exchange membranes and electrolyte layers, and electrode reactions. We show that the largest contribution to the energy required comes from the bipolar membrane, motivating further research on bipolar membrane development. We also discuss the role of ion exchange membranes in this system: these membranes must provide high ion conductivity while providing selectivity against leakage of acid and base products. Several commercial membranes were screened for conductivity and water content, and their electrodialysis performance is compared. Finally, we use technoeconomic modeling to assess how electrodialysis operating conditions and electrolyte composition affect energy, land, and water demands of a continuously operating direct air capture process, with redox-mediated salt splitting as the centerpiece.

Figure 1
(Invited) Industrial Relevance of Pulsed Electrochemical Methods
Authors: Hansal Wolfgang , Hansal Selma , Weiß Susanna 
Published: February 2024

Industrial demands are the driving force on any optimization and development process for electrochemical plating processes and coatings. The classical demands focused on the mechanical properties such as wear resistance and hardness as well as the stability against corrosion.
The galvanic coatings were tailored for meeting these requirements, defining the electrochemical systems that are currently standard in galvanic protection of industrial parts.
With the introduction of new applications and production methods over the last 10 to 15 years additional functionality has been seeked by the industry, including chemical stability, bio-compatibility, microstructured surfaces, lubrication effects, magnetic properties and the ability of shock absorbance. Coating had to be adjusted, leading to the industrial realisation of dispersion and compound coatings, alloy deposition on a wider scale and Pulse (reverse) plating. While these, from an industrial perspective, relatively new plating processes already required some major rethinking of the traditional galvanic industry, the industrial requirements got even more demanding over the last few years. Especially with the origin of new industrial production methods, the homogenous treatment and coating of e.g. complex bionical structures became relevant.
In order to follow the changing demands, the transfer from the classical thermodynamically controlled direct current or constant potential based surface treatment towards a kinetically controlled pulsed surface finishing has to be executed.
While pulse plating is the most popular representation of these categories of finishing processes, pulsed electrochemical processes comprise a much larger variety of methods. Among these, pulse anodization, pulsed plasma electrolytic oxidation (PEO), pulsed electropolishing, electrochemical machining (ECM) and the recently introduced Hirtisation process are industrially used.
The presenation will give an overview of possibilities for electrochemical engineering of surfaces for high-end technical applications by pulsed electrochemical techniques.