Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ammonia decomposition catalysis using non-stoichiometric lithium imide.

ABSTRACT: We demonstrate that non-stoichiometric lithium imide is a highly active catalyst for the production of high-purity hydrogen from ammonia, with superior ammonia decomposition activity to a number of other catalyst materials. Neutron powder diffraction measurements reveal that the catalyst deviates from pure imide stoichiometry under ammonia flow, with active catalytic behaviour observed across a range of stoichiometry values near the imide. These measurements also show that hydrogen from the ammonia is exchanged with, and incorporated into, the bulk catalyst material, in a significant departure from existing ammonia decomposition catalysts. The efficacy of the lithium imide-amide system not only represents a more promising catalyst system, but also broadens the range of candidates for amide-based ammonia decomposition to include those that form imides.

SUBMITTER: Makepeace JW

PROVIDER: S-EPMC5707451 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Ammonia decomposition catalysis using non-stoichiometric lithium imide.

Makepeace Joshua W JW Wood Thomas J TJ Hunter Hazel M A HMA Jones Martin O MO David William I F WIF

Chemical science 20150507 7

We demonstrate that non-stoichiometric lithium imide is a highly active catalyst for the production of high-purity hydrogen from ammonia, with superior ammonia decomposition activity to a number of other catalyst materials. Neutron powder diffraction measurements reveal that the catalyst deviates from pure imide stoichiometry under ammonia flow, with active catalytic behaviour observed across a range of stoichiometry values near the imide. These measurements also show that hydrogen from the ammo ...[more]

PMID: 29218150

Similar Datasets

Highly efficient decomposition of ammonia using high-entropy alloy catalysts.

Project description:Ammonia represents a promising liquid fuel for hydrogen storage, but its large-scale application is limited by the need for precious metal ruthenium (Ru) as catalyst. Here we report on highly efficient ammonia decomposition using novel high-entropy alloy (HEA) catalysts made of earth abundant elements. Quinary CoMoFeNiCu nanoparticles are synthesized in a single solid-solution phase with robust control over the Co/Mo atomic ratio, including those ratios considered to be immiscible according to the Co-Mo bimetallic phase diagram. These HEA nanoparticles demonstrate substantially enhanced catalytic activity and stability for ammonia decomposition, with improvement factors achieving >20 versus Ru catalysts. Catalytic activity of HEA nanoparticles is robustly tunable by varying the Co/Mo ratio, allowing for the optimization of surface property to maximize the reactivity under different reaction conditions. Our work highlights the great potential of HEAs for catalyzing chemical transformation and energy conversion reactions.

| S-EPMC6728353 | biostudies-literature

A Crosslinked Polyethyleneglycol Solid Electrolyte Dissolving Lithium Bis(trifluoromethylsulfonyl)imide for Rechargeable Lithium Batteries.

Project description:Replacing liquid electrolytes with solid ones can provide advantages in safety, and all-solid-state batteries with solid electrolytes are proposed to solve the issue of the formation of lithium dendrites. In this study, a crosslinked polymer composite solid electrolyte was presented, which enabled the construction of lithium batteries with outstanding electrochemical behavior over long-term cycling. The crosslinked polymeric host was synthesized through polymerization of the terminal amines of O,O-bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol and terminal epoxy groups of bisphenol A diglycidyl ether at 90 °C and provided an amorphous matrix for Li+ dissolution. This composite solid electrolyte containing Li+ salt and garnet filler exhibited high flexibility, which supported the formation of favorable interfaces with the active materials, and possessed enough mechanical strength to suppress the penetration of lithium dendrites. Ionic conductivities higher than 5.0×10-4 S cm-1 above 45 °C were obtained as well as a wide electrochemical stability window (>4.51 V vs. Li/Li+ ) and a high Li+ diffusion coefficient (≈16.6×10-13 m2 s-1 ). High cycling stability (>500 cycles or 1000 h) was demonstrated.

| S-EPMC6856689 | biostudies-literature

Cobalt-based Catalysts for Ammonia Decomposition.

Project description:An effect of promoters such as calcium, aluminium, and potassium oxides and also addition of chromium and manganese on the structure of cobalt catalysts was examined. Studies of the catalytic ammonia decomposition over the cobalt catalysts are presented. The studies of the ammonia decomposition were carried out for various ammonia-hydrogen mixtures in which ammonia concentration varied in the range from 10% to 100%. Co(0) catalyst, promoted by oxides of aluminium, calcium, and potassium, showed the highest activity in the ammonia decomposition reaction. Contrary to expectations, it was found that chromium and manganese addition into the catalysts decreased their activity.

| S-EPMC5458937 | biostudies-other

Stoichiometric and Non-Stoichiometric Hydrates of Brucine.

Project description:The complex interplay of temperature and water activity (aw) / relative humidity (RH) on the solid form stability and transformation pathways of three hydrates (HyA, HyB and HyC), an isostructural dehydrate (HyAdehy ), an anhydrate (AH) and amorphous brucine has been elucidated and the transformation enthalpies quantified. The dihydrate (HyA) shows a non-stoichimetric (de)hydration behavior at RH < 40% at 25 °C and the removal of the water molecules results in an isomorphic dehydrate structure. The metastable dehydration product converts to AH upon storage at driest conditions or to HyA if exposed to moisture. HyB is a stoichiometric tetrahydrate. The loss of the water molecules causes HyB to collapse to an amorphous phase. Amorphous brucine transforms to AH at RH < 40% RH and a mixture of hydrated phases at higher RH values. The third hyrdate (HyC) is only stable at RH ≥ 55% at 25 °C and contains 3.65 to 3.85 mole equivalent of water. Dehydration of HyC occurs in one step at RH < 55% at 25 °C or upon heating and AH is obtained. The AH is the thermodynamically most stable phase of brucine at RH < 40% at 25 °C. Depending on the conditions, temperature and aw, each of the three hydrates becomes the thermodynamically most stable form. This study demonstrates the importance of applying complimentary analytical techniques and appropriate approaches for understanding the stability ranges and transition behavior between the solid forms of compounds with multiple hydrates.

| S-EPMC5486439 | biostudies-literature

Lithium diisopropylamide-mediated ortholithiations: lithium chloride catalysis.

Project description:Ortholithiations of a range of arenes mediated by lithium diisopropylamide (LDA) in THF at -78 degrees C reveal substantial accelerations by as little as 0.5 mol % of LiCl (relative to LDA). Substrate dependencies suggest a specific range of reactivity within which the LiCl catalysis is optimal. Standard protocols with unpurified commercial samples of n-butyllithium to prepare LDA or commercially available LDA show marked batch-dependent rates--up to 100-fold--that could prove significant to the unwary practitioner. Other lithium salts elicit more modest accelerations. The mechanism is not discussed.

| S-EPMC2765536 | biostudies-other

A Poly(ethylene oxide)/Lithium bis(trifluoromethanesulfonyl)imide-Coated Polypropylene Membrane for a High-Loading Lithium-Sulfur Battery.

Project description:In lithium-sulfur cells, the dissolution and relocation of the liquid-state active material (polysulfides) lead to fast capacity fading and low Coulombic efficiency, resulting in poor long-term electrochemical stability. To solve this problem, we synthesize a composite using a gel polymer electrolyte and a separator as a functional membrane, coated with a layer of poly(ethylene oxide) (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The PEO/LiTFSI-coated polypropylene membrane slows the diffusion of polysulfides and stabilizes the liquid-state active material within the cathode region of the cell, while allowing smooth lithium-ion transfer. The lithium-sulfur cells with the developed membrane demonstrate a high charge-storage capacity of 1212 mA∙h g-1, 981 mA∙h g-1, and 637 mA∙h g-1 at high sulfur loadings of 2 mg cm-2, 4 mg cm-2, and 6 mg cm-2, respectively, and maintains a high reversible capacity of 534 mA∙h g-1 after 200 cycles, proving its ability to block the irreversible diffusion of polysulfides and to maintain the stabilized polysulfides as the catholyte for improved electrochemical utilization and stability. As a comparison, reference and control cells fabricated using a PEO-coated polypropylene membrane and a regular separator, respectively, show a poor capacity of 662 mA∙h g-1 and a short cycle life of 50 cycles.

| S-EPMC7918845 | biostudies-literature

Experimental dataset on electrolyte mixtures containing fluoroethylene carbonate and lithium bis(trifluoromethanesulfonyl)imide.

Project description:These data and analyses support the research article "Low-flammable electrolytes with fluoroethylene carbonate based solvent mixtures and lithium bis(trifluoromethanesulfonyl)-imide (LiTFSI) for lithium-ion batteries" [1]. The data and analyses presented here include fitted data for density measurements, temperature dependence of density and specific volume of the mixtures, detailed viscosity measurements and conductivity data, current density plots with respect to anodic aluminum dissolution, half-cell C-rate capability of mixtures with the additives used in research article as well as the SEM images and EDX data of the full-cell with the electrolyte selected and controlled.

| S-EPMC6373205 | biostudies-literature

Patched bimetallic surfaces are active catalysts for ammonia decomposition.

Project description:Ammonia decomposition is often used as an archetypical reaction for predicting new catalytic materials and understanding the very reason of why some reactions are sensitive on material's structure. Core-shell or surface-segregated bimetallic nanoparticles expose outstanding activity for many heterogeneously catalysed reactions but the reasons remain elusive owing to the difficulties in experimentally characterizing active sites. Here by performing multiscale simulations in ammonia decomposition on various nickel loadings on platinum (111), we show that the very high activity of core-shell structures requires patches of the guest metal to create and sustain dual active sites: nickel terraces catalyse N-H bond breaking and nickel edge sites drive atomic nitrogen association. The structure sensitivity on these active catalysts depends profoundly on reaction conditions due to kinetically competing relevant elementary reaction steps. We expose a remarkable difference in active sites between transient and steady-state studies and provide insights into optimal material design.

| S-EPMC4633960 | biostudies-literature

The Effect of Lithium Doping on the Sintering and Grain Growth of SPS-Processed, Non-Stoichiometric Magnesium Aluminate Spinel.

Project description:The effects of lithium doping on the sintering and grain growth of non-stoichiometric nano-sized magnesium aluminate spinel were studied using a spark plasma sintering (SPS) apparatus. Li-doped nano-MgO·nAl₂O₃ spinel (n = 1.06 and 1.21) powders containing 0, 0.20, 0.50 or 1.00 at. % Li were synthesized by the solution combustion method and dense specimens were processed using a SPS apparatus at 1200 °C and under an applied pressure of 150 MPa. The SPS-processed samples showed mutual dependency on the lithium concentration and the alumina-to-magnesia ratio. For example, the density and hardness values of near-stoichiometry samples (n = 1.06) showed an incline up to 0.51 at. % Li, while in the alumina rich samples (n = 1.21), these values remained constant up to 0.53 at. % Li. Studying grain growth revealed that in the Li-MgO·nAl₂O₃ system, grain growth is limited by Zener pining. The activation energies of undoped, 0.2 and 0.53 at. % Li-MgO·1.21Al₂O₃ samples were 288 ± 40, 670 ± 45 and 543 ± 40 kJ·mol-1, respectively.

| S-EPMC5456799 | biostudies-other

Tuning lithium-peroxide formation and decomposition routes with single-atom catalysts for lithium-oxygen batteries.

Project description:Lithium-oxygen batteries with ultrahigh energy density have received considerable attention as of the future energy storage technologies. The development of effective electrocatalysts and a corresponding working mechanism during cycling are critically important for lithium-oxygen batteries. Here, a single cobalt atom electrocatalyst is synthesized for lithium-oxygen batteries by a polymer encapsulation strategy. The isolated moieties of single atom catalysts can effectively regulate the distribution of active sites to form micrometre-sized flower-like lithium peroxide and promote the decomposition of lithium peroxide by a one-electron pathway. The battery with single cobalt atoms can operate with high round-trip efficiency (86.2%) and long-term stability (218 days), which is superior to a commercial 5?wt% platinum/carbon catalyst. We reveal that the synergy between a single atom and the support endows the catalyst with excellent stability and durability. The promising results provide insights into the design of highly efficient catalysts for lithium-oxygen batteries and greatly expand the scope of future investigation.

| S-EPMC7198606 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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