Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Making ammonia from nitrogen and water microdroplets.

ABSTRACT: Water (H₂O) microdroplets are sprayed onto a magnetic iron oxide (Fe₃O₄) and Nafion-coated graphite mesh using compressed N₂ or air as the nebulizing gas. The resulting splash of microdroplets enters a mass spectrometer and is found to contain ammonia (NH₃). This gas-liquid-solid heterogeneous catalytic system synthesizes ammonia in 0.2 ms. The conversion rate reaches 32.9 ± 1.38 nmol s^-1 cm^-2 at room temperature without application of an external electric potential and without irradiation. Water microdroplets are the hydrogen source for N₂ in contact with Fe₃O₄. Hydrazine (H₂NNH₂) is also observed as a by-product and is suspected to be an intermediate in the formation of ammonia. This one-step nitrogen-fixation strategy to produce ammonia is eco-friendly and low cost, which converts widely available starting materials into a value-added product.

SUBMITTER: Song X

PROVIDER: S-EPMC10120050 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Making ammonia from nitrogen and water microdroplets.

Song Xiaowei X Basheer Chanbasha C Zare Richard N RN

Proceedings of the National Academy of Sciences of the United States of America 20230410 16

Water (H2O) microdroplets are sprayed onto a magnetic iron oxide (Fe3O4) and Nafion-coated graphite mesh using compressed N2 or air as the nebulizing gas. The resulting splash of microdroplets enters a mass spectrometer and is found to contain ammonia (NH3). This gas-liquid-solid heterogeneous catalytic system synthesizes ammonia in 0.2 ms. The conversion rate reaches 32.9 ± 1.38 nmol s-1 cm-2 at room temperature withou ...[more]

PMID: 37036968

Similar Datasets

Radiocatalytic ammonia synthesis from nitrogen and water.

Project description:The development of alternative methods to the Haber-Bosch process for ammonia (NH3) synthesis is a pressing and formidable challenge. Nuclear energy represents a low-carbon, efficient and stable source of power. The harnessing of nuclear energy to drive nitrogen (N2) reduction not only allows 'green' NH3 synthesis, but also offers the potential for the storage of nuclear energy as a readily transportable zero-carbon fuel. Herein, we explore radiocatalytic N2 fixation to NH3 induced by γ-ray radiation. Hydrated electrons (e- aq) that are generated from water radiolysis enable N2 reduction to produce NH3. Ru-based catalysts synthesized by using γ-ray radiation with excellent radiation stability substantially improve NH3 production in which the B5 sites of Ru particles may play an important role in the activation of N2. By benefitting from the remarkable penetrating power of γ-ray radiation, radiocatalytic NH3 synthesis can proceed in an autoclave under appropriate pressure conditions, resulting in an NH3 concentration of ≤5.1 mM. The energy conversion efficiency of the reaction is as high as 563.7 mgNH3·MJ-1. This radiocatalytic chemistry broadens the research scope of catalytic N2 fixation while offering promising opportunities for converting nuclear energy into chemical energy.

| S-EPMC11493089 | biostudies-literature

Continuous ammonia synthesis from water and nitrogen via contact electrification.

Project description:We synthesized ammonia (NH3) by bubbling nitrogen (N2) gas into bulk liquid water (200 mL) containing 50 mg polytetrafluoroethylene (PTFE) particles (~5 µm in diameter) suspended with the help of a surfactant (Tween 20, ~0.05 vol.%) at room temperature (25 °C). Electron spin resonance spectroscopy and density functional theory calculations reveal that water acts as the proton donor for the reduction of N2. Moreover, isotopic labeling of the N2 gas shows that it is the source of nitrogen in the ammonia. We propose a mechanism for ammonia generation based on the activation of N2 caused by electron transfer and reduction processes driven by contact electrification. We optimized the pH of the PTFE suspension at 6.5 to 7.0 and employed ultrasonic mixing. We found an ammonia production rate of ~420 μmol L-1 h-1 per gram of PTFE particles for the conditions described above. This rate did not change more than 10% over an 8-h period of sustained reaction.

| S-EPMC10823170 | biostudies-literature

Onsite ammonia synthesis from water vapor and nitrogen in the air.

Project description:An innovative method for onsite ammonia synthesis under ambient conditions has been developed using a catalyst mesh composed of magnetite (Fe3O4) and Nafion polymer. We pass air through the catalyst, which condenses microdroplets from atmospheric water vapor and uses nitrogen from the air, resulting in ammonia concentrations ranging from 25 to 120 μM in 1 hour, depending on local relative humidity. Operated at room temperature and atmospheric pressure, this technique eliminates the need for additional electricity or radiation, thereby substantially reducing carbon dioxide emissions compared to the traditional Haber-Bosch process. In laboratory experiments, we further optimized the reaction conditions and scaled up the process. After 2 hours of spraying, the ammonia concentration increased to 270.2 ± 25.1 μM. In addition, we present a portable device designed for onsite ammonia production which consistently produces an ammonia concentration that is adequate for some agricultural irrigation purposes.

| S-EPMC11640998 | biostudies-literature

Water flooding behavior in flow cells for ammonia production via electrocatalytic nitrogen reduction.

Project description:The green production of ammonia, in an electrochemical flow cell under ambient conditions, is a promising way to replace the energy-intensive Haber-Bosch process. In the operation of this flow cell with an alkaline electrolyte, water is produced at the anode but also required as an essential reactant at the cathode for nitrogen reduction. Hence, water from the anode is expected to diffuse through the membrane to the cathode to compensate for the water needed for nitrogen reduction. Excessive water permeation, however, tends to increase the possibility of water flooding, which would not only create a large barrier for nitrogen delivery and availability, but also lead to severe hydrogen evolution as side reaction, and thus significantly lower the ammonia production rate and Faradaic efficiency. In this work, the water flooding phenomenon in flow cells for ammonia production via electrocatalytic nitrogen reduction is verified via the visualization approach and the electrochemical cell performance. In addition, the effects of the nitrogen flow rate, applied current density, and membrane thickness on the water crossover flux and ammonia production rate are comprehensively studied. The underlying mechanism of water transport through the membrane, including diffusion and electro-osmotic drag, is precisely examined and specified to provide more insight on water flooding behavior in the flow cell.

| S-EPMC11197710 | biostudies-literature

Size-dependent charge transfer between water microdroplets.

Project description:Contact electrification (CE) in water has attracted much attention, owing to its potential impacts on the chemical reactions, such as the recent discovery of spontaneous generation of hydrogen peroxide (H2O2) in water microdroplets. However, current studies focus on the CE of bulk water, the measurement of CE between micrometer-size water droplets is a challenge and its mechanism still remains ambiguous. Here, a method for quantifying the amount of charge carried by the water microdroplets produced by ultrasonic atomization is proposed. In the method, the motions of water microdroplets in a uniform electric field are observed and the electrostatic forces on the microdroplets are calculated based on the moving speed of the microdroplets. It is revealed that the charge transfer between water microdroplets is size-dependent. The large microdroplets tend to be positively charged while the small microdroplets tend to receive negative charges, implying that the negative charges transfer from large microdroplets to the small microdroplets during ultrasonic atomization. Further, a theoretical model for microdroplets charging is proposed, in which the curvature-induced surface potential/energy difference is suggested to be responsible for the charge transfer between microdroplets. The findings show that the electric field strength between two microdroplets with opposite charges during separation is strong enough to convert OH‒ to OH*, providing evidence for the CE-induced spontaneous generation of H2O2 in water microdroplets.

| S-EPMC10401017 | biostudies-literature

On the formation of hydrogen peroxide in water microdroplets.

Project description:Recent reports on the formation of hydrogen peroxide (H2O2) in water microdroplets produced via pneumatic spraying or capillary condensation have garnered significant attention. How covalent bonds in water could break under such mild conditions challenges our textbook understanding of physical chemistry and water. While there is no definitive answer, it has been speculated that ultrahigh electric fields at the air-water interface are responsible for this chemical transformation. Here, we report on our comprehensive experimental investigation of H2O2 formation in (i) water microdroplets sprayed over a range of liquid flow-rates, (shearing) air flow rates, and air composition, and (ii) water microdroplets condensed on hydrophobic substrates formed via hot water or humidifier under controlled air composition. Specifically, we assessed the contributions of the evaporative concentration and shock waves in sprays and the effects of trace O3(g) on the H2O2 formation. Glovebox experiments revealed that the H2O2 formation in water microdroplets was most sensitive to the air-borne ozone (O3) concentration. In the absence of O3(g), we could not detect H2O2(aq) in sprays or condensates (detection limit ≥250 nM). In contrast, microdroplets exposed to atmospherically relevant O3(g) concentration (10-100 ppb) formed 2-30 µM H2O2(aq), increasing with the gas-liquid surface area, mixing, and contact duration. Thus, the water surface area facilitates the O3(g) mass transfer, which is followed by the chemical transformation of O3(aq) into H2O2(aq). These findings should also help us understand the implications of this chemistry in natural and applied contexts.

| S-EPMC8890092 | biostudies-literature

Acid Catalysis with Alkane/Water Microdroplets in Ionic Liquids.

Project description:Ionic liquids are composed of an organic cation and a highly delocalized perfluorinated anion, which remain tight to each other and neutral across the extended liquid framework. Here we show that n-alkanes in millimolar amounts enable a sufficient ion charge separation to release the innate acidity of the ionic liquid and catalyze the industrially relevant alkylation of phenol, after generating homogeneous, self-stabilized, and surfactant-free microdroplets (1-5 μm). This extremely mild and simple protocol circumvents any external additive or potential ionic liquid degradation and can be extended to water, which spontaneously generates microdroplets (ca. 3 μm) and catalyzes Brönsted rather than Lewis acid reactions. These results open new avenues not only in the use of ionic liquids as acid catalysts/solvents but also in the preparation of surfactant-free, well-defined ionic liquid microemulsions.

| S-EPMC8243323 | biostudies-literature

Characterization of laser-driven proton acceleration from water microdroplets.

Project description:We report on a proton acceleration experiment in which high-intensity laser pulses with a wavelength of 0.4 μm and with varying temporal intensity contrast have been used to irradiate water droplets of 20 μm diameter. Such droplets are a reliable and easy-to-implement type of target for proton acceleration experiments with the potential to be used at very high repetition rates. We have investigated the influence of the laser's angle of incidence by moving the droplet along the laser polarization axis. This position, which is coupled with the angle of incidence, has a crucial impact on the maximum proton energy. Central irradiation leads to an inefficient coupling of the laser energy into hot electrons, resulting in a low maximum proton energy. The introduction of a controlled pre-pulse produces an enhancement of hot electron generation in this geometry and therefore higher proton energies. However, two-dimensional particle-in-cell simulations support our experimental results confirming, that even slightly higher proton energies are achieved under grazing laser incidence when no additional pre-plasma is present. Illuminating a droplet under grazing incidence generates a stream of hot electrons that flows along the droplet's surface due to self-generated electric and magnetic fields and ultimately generates a strong electric field responsible for proton acceleration. The interaction conditions were monitored with the help of an ultra-short optical probe laser, with which the plasma expansion could be observed.

| S-EPMC6868211 | biostudies-literature

Dynamics of microdroplets over the surface of hot water.

Project description:When drinking a cup of coffee under the morning sunshine, you may notice white membranes of steam floating on the surface of the hot water. They stay notably close to the surface and appear to almost stick to it. Although the membranes whiffle because of the air flow of rising steam, peculiarly fast splitting events occasionally occur. They resemble cracking to open slits approximately 1 mm wide in the membranes, and leave curious patterns. We studied this phenomenon using a microscope with a high-speed video camera and found intriguing details: i) the white membranes consist of fairly monodispersed small droplets of the order of 10 μm; ii) they levitate above the water surface by 10 ~ 100 μm; iii) the splitting events are a collective disappearance of the droplets, which propagates as a wave front of the surface wave with a speed of 1 ~ 2 m/s; and iv) these events are triggered by a surface disturbance, which results from the disappearance of a single droplet.

| S-EPMC4306967 | biostudies-literature

Catalyst-free, highly selective synthesis of ammonia from nitrogen and water by a plasma electrolytic system.

Project description:There is a growing need for scalable ammonia synthesis at ambient conditions that relies on renewable sources of energy and feedstocks to replace the Haber-Bosch process. Electrically driven approaches are an ideal strategy for the reduction of nitrogen to ammonia but, to date, have suffered from low selectivity associated with the catalyst. Here, we present a hybrid electrolytic system characterized by a gaseous plasma electrode that facilitates the study of ammonia formation in the absence of any material surface. We find record-high faradaic efficiency (up to 100%) for ammonia from nitrogen and water at atmospheric pressure and temperature with this system. Ammonia measurements under varying reaction conditions in combination with scavengers reveal that the unprecedented selectivity is achieved by solvated electrons produced at the plasma-water interface, which react favorably with protons to produce the key hydrogen radical intermediate. Our results demonstrate that limitations in selectivity can be circumvented by using catalyst-free solvated electron chemistry. In the absence of adsorption steps, the importance of controlling proton concentration and transport is also revealed.

| S-EPMC6357762 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data