A5005186532- Ammonia Synthesis and Nitrogen Reduction
- Hydrogen Storage and Materials
- Electrocatalysts for Energy Conversion
- Electrochemical Analysis and Applications
- Advanced Photocatalysis Techniques
- Caching and Content Delivery
- Fuel Cells and Related Materials
- CO2 Reduction Techniques and Catalysts
- Muon and positron interactions and applications
- Semiconductor materials and devices
- Chemical Synthesis and Characterization
- Spectroscopy and Quantum Chemical Studies
- Machine Learning in Materials Science
- Innovative Microfluidic and Catalytic Techniques Innovation
- Advanced battery technologies research
Technical University of Denmark
2020-2023
Technical University of Munich
2023
Danish Geotechnical Society
2020
Owing to the worrying increase in carbon dioxide concentrations atmosphere, there is a need electrify fossil-fuel–powered chemical processes such as Haber-Bosch ammonia synthesis. Lithium-mediated electrochemical nitrogen reduction has shown preliminary promise but still lacks sufficient faradaic efficiency and formation rate be industrially relevant. Here, we show that oxygen, previously believed hinder reaction, actually greatly improves stability of lithium-mediated when added reaction...
Novel cycling method that significantly increases stability and efficiency of the lithium-mediated electrochemical nitrogen reduction process.
The lithium-mediated ammonia synthesis is so far the only proven electrochemical way to produce with promising faradaic efficiencies (FEs). However, make this process commercially competitive, formation rates per geometric surface area need be increased significantly. In study, we current density by synthesizing high Cu electrodes through hydrogen bubbling templating (HBT) on Ni foam substrates. With these electrodes, achieved of 46.0 ± 6.8 nmol s–1 cmgeo–2, at a −100 mA/cmgeo–2 20 bar...
Lithium-mediated electrochemical ammonia synthesis (LiMEAS) in non-aqueous media is a promising technique for efficient and green synthesis. Compared to the widely used Haber-Bosch process, method reduces CO2 emissions zero due application of hydrogen. However, medium encounters alkali metal lithium organic components at high negative potentials electrolysis, which leads formation byproducts. To assess environmental risk this method, standardized analytical methods towards understanding...
Ammonia is one of the most produced chemicals worldwide and currently synthesized by Haber-Bosch process, which a thermally catalyzed method that requires high pressures temperatures. These harsh conditions, in addition to prerequisite steam reforming leads about 1 % annual energy consumption 1.4 global CO 2 emission. One way mitigate some process produce ammonia electrochemically, utilizing renewable sources. The electrochemical synthesis faces several big issues. being selectivity, since...
Li-mediated electrochemical ammonia synthesis (LiMEAS), a potential alternative to conventional thermochemical synthesis, is enabled by non-aqueous electrolytes with precisely controlled proton activity. However, the effects of generating anode reactions, such as hydrogen or electrolyte oxidation, unknown but crucially important for enabling steady-state LiMEAS without need sacrificial sources. By employing cyclic voltammetry on platinum electrode, we demonstrate that protons are generated...
Pulsed electrolysis has shown promise to improve CO(2) reduction activity and steer selectivity by potential pulsing. Nevertheless, a detailed mechanistic understanding of the transient upon pulsing is still lacking. Utilizing electrochemical mass spectrometry, we demonstrate highly active but short-lived methane hydrogen transients for pulsed CO in phosphate buffer. Compared with absence borate buffer, conclude that arise from an initial presence local depletion ions, acting as facile...
Abstract In this work the successful operando detection of synthesized ammonia from nitrogen reduction in non‐aqueous electrolytes with an electron‐ionization mass spectrometer was reported. Using selective ionization at 22 eV together a highly sensitive micro‐chip‐based electrochemistry spectrometry set‐up, quantitative produced down to few pmol s −1 as well aqueous demonstrated. The well‐defined electrochemical and transport environment thin‐layer cell allowed for fundamental studies...
Electrochemistry–mass spectrometry is a versatile and reliable tool to study the interfacial reaction rates of Faradaic processes with high temporal resolutions. However, measured mass spectrometric signals typically do not directly correspond partial current density toward analyte due transport effects. Here, we introduce mathematical framework, grounded on model, obtain quantitative truly dynamic from spectrometer signal by means deconvolution. Furthermore, it shown that time resolution...
Abstract In this study, ex situ and operando X‐ray absorption spectroscopy (XAS) is employed to shed light on structure degradation mechanism of Fe‐based catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Ex XAS pristine Fe 0.07 Zr 0.93 O 2‐δ /C catalyst confirms incorporation 3+ ZrO 2 clearly exclude any significant presence Fe−N−C‐type structures. The edge shift data in‐house aged samples demonstrates a mixed oxidation state (Fe 2+ ),...
Abstract We present a highly sensitive and versatile Si-based μ -reactor for photocatalytic experiments. The can be operated in front side (through borosilicate window) as well backside the catalyst support) illumination. is sealed by compressing microchip, parafilm gasket supported four screws. This design allows fast reliable assembly of microchip re-usable several independent experiments, making presented ideal screening studies. analyze volatile reactants on-line connecting to...
Up to date copper is the only electrocatalyst with relevant activity for reduction of CO 2 and value added hydrocarbons alcohols 1 . However, studies over nanostructured catalysts, which are believed have a high abundancy active sites, were hindered by coppers instability in alkaline conditions. This makes Cu-based catalysts prone dissolution during immersion into electrolyte. Recently, we reported on an experimental methodology immersing under potential control reactors generally used...