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- ItemResearch Data in Chemistry – Results of the first NFDI4Chem Community Survey(Weinheim : Wiley-VCH, 2020) Herres‐Pawlis, Sonja; Liermann, Johannes C.; Koepler, OliverGood research data management (RDM) requires a constant endeavour of the researchers but – first and foremost – user-friendly infrastructure and well accepted standards need to be developed for the researchers. The national research data infrastructure initiative for chemistry in Germany NFDI4Chem sets out to embrace the challenge of creating a general research data management portal and hereby connecting already existing infrastructure as well as to foster the cultural change in chemistry towards digitalization by developing general minimum information standards for all methods used and teaching RDM principles to the community. In order to serve the needs of the chemical community at its best, NFDI4Chem accomplishes regular community surveys. The first survey has been performed in 2019 and the results were condensed into the NFDI4Chem proposal. This article summarizes the design of the study and its results. With regard to the project development, this first national survey serves as zero-point of all upcoming efforts in research data management.
- ItemToward Continuous Electrochemical Synthesis of Ferrate(Weinheim : Wiley-VCH, 2024) Kupec, Robin; Plischka, Wenzel; Duman, Ediz; Schneider, Selina; Weidlich, Claudia; Wessling, Matthias; Keller, Robert; Stöckl, MarkusFerrate (Fe(VI)) is of great interest in energy storage solutions, organic synthesis, and wastewater treatment due to its decent oxidation potential and non-toxic end-product formation, making it a green oxidizer. The electrochemical generation of ferrate in NaOH at current densities of j ≥ 100 mA cm−2 is presented using low-cost sacrificial iron anodes, mild steel, and spheroidal graphite cast iron (ductile iron). Under optimized reaction parameters with 40 wt.% (14 m) NaOH and a ZrO2-based diaphragm, spheroidal graphite cast iron shows no signs of passivation in 5 h experiments even at j = 150 mA cm−2. The results are used in a novel electrolysis cell with a combined geometric anode surface area of 230 cm2, incorporated in a mini-plant suitable for continuous synthesis. This setup produces a peak ferrate concentration of 10.1 g L−1 (84 mm) after 5 h in 1.6 L anolyte volume, resulting in a total ferrate mass of 16.2 g. Optimal electrolysis temperatures are between 35 and 50 °C. The highest current efficiency is 63.0%, and the lowest specific energy consumption is 9.2 kWh kg−1 ferrate. The presented work is an essential step toward the continuous electrochemical synthesis of ferrate using sacrificial anodes under basic conditions.
- ItemAll Electrochemical Synthesis of Performic Acid Starting from CO2, O2, and H2O(Weinheim : Wiley-VCH, 2025) Dinges, Ida; Pyschik, Markus; Schütz, Julian; Schneider, Selina; Klemm, Elias; Waldvogel, Siegfried R.; Stöckl, MarkusDriven by anthropogenic climate change, innovative approaches to defossilize the chemical industry are required. Herein, the first all-electrochemical feasibility study for the complete electrosynthesis of the strong oxidizer and effective disinfectant performic acid is presented. Its synthesis is achieved solely from CO2, O2, and H2O in a two-step process. Initially, CO2 is electrochemically reduced to formate employing Bi2O3-based gas diffusion electrodes in a phosphate-buffered electrolyte. Thereby, high formate concentration (500.7 ± 0.6 mmol L−1) and high Faradaic efficiency (86.3 ± 0.3%) are achieved at technically relevant current density (150 mA cm−2). Subsequently, the formate acts as (storable) feed electrolyte for the second electrolysis step. Employing carbon-based gas diffusion electrodes, O2 is reduced to H2O2 and performic acid is directly formed in situ. As before, high H2O2 concentration (1.27 ± 0.06 mol L−1) and high Faradaic efficiency (85.3 ± 5.4%) are achieved. Furthermore, performic acid concentration suitable for disinfection is obtained (82 ± 11 mmol L−1). In summary, this innovative feasibility study highlights the potential of combining electrochemical CO2 reduction with H2O2 electrosynthesis, which could provide sustainable access to performic acid in the future.
- ItemCoupling of CO2 Electrolysis with Parallel and Semi- Automated Biopolymer Synthesis – Ex-Cell and without Downstream Processing(Weinheim : Wiley-VCH, 2024) Dinges, Ida; Depentori, Ina; Gans, Lisa; Holtmann, Dirk; Waldvogel, Siegfried R.; Stöckl, MarkusImportant improvements have been achieved in developing the coupling of electrochemical CO2 reduction to formate with its subsequent microbial conversion to polyhydroxybutyrate (PHB) by Cupriavidus necator. The CO2 based formate electrosynthesis was optimised by electrolysis parameter adjustment and application of Sn based gas diffusion electrodes reaching almost 80 % Faradaic efficiency at 150 mA cm−2. Thereby, catholyte with the high formate concentration of 441±9 mmol L−1 was generated as feedstock without intermediate downstream processing for semi-automated formate feeding into a fed-batch reactor system. Moreover, microbial formate conversion to PHB was studied further, optimised, and successfully scaled from shake flasks to semi-automated bioreactors. Therein, a PHB per formate ratio of 16.5±4.0 mg g−1 and a PHB synthesis rate of 8.4±2.1 mg L−1 OD−1 h−1 were achieved. By this process combination, an almost doubled overall process yield of 22.3±5.5 % was achieved compared to previous reports. The findings allow a detailed evaluation of the overall CO2 to PHB conversion, providing the basis for potential technical exploitation.
- ItemGeopolymer Based Electrodes as New Class of Material for Electrochemical CO2 Reduction(Weinheim : Wiley-VCH, 2023) Schuster, Jürgen; Ukrainczyk, Neven; Koenders, Eddie; Stöckl, MarkusTo achieve a successful transition to a sustainable carbon and energy management, it is essential to both reduce CO2 emissions and develop new technologies that utilize CO2 as a starting substrate. In this study, we demonstrate for the first-time the functionalization of geopolymer binder (GP) with Sn for electrochemical CO2 reduction (eCO2RR) to formate. By substituting cement with Sn-GP, we have merged CO2 utilisation and emission reduction. Using a simple mixing procedure, we were able to obtain a pourable mortar containing 5 vol. % Sn-powder. After hardening, the Sn-GP electrodes were characterized for their mechanical and CO2 electrolysis performance. In 10 h electrolyses, formate concentrations were as high as 22.7±0.9 mmol L−1 with a corresponding current efficiency of 14.0±0.5 % at a current density of 20 mA cm−2. Our study demonstrates the successful design of GP-electrodes as a new class of hybrid materials that connect eCO2RR and construction materials.