Browse
Submit Data
Databases
API
Help

Dataset Information

31 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

In-situ abiogenic methane synthesis from diamond and graphite under geologically relevant conditions

ABSTRACT: Diamond and graphite are fundamental sources of carbon in the upper mantle, and their reactivity with H2-rich fluids present at these depths may represent the key to unravelling deep abiotic hydrocarbon formation. We demonstrate an unexpected high reactivity between carbons’ most common allotropes, diamond and graphite, with hydrogen at conditions comparable with those in the Earth’s upper mantle along subduction zone thermal gradients. Between 0.5-3 GPa and at temperatures as low as 300 °C, carbon reacts readily with H2 yielding methane (CH4), whilst at higher temperatures (500 °C and above), additional light hydrocarbons such as ethane (C2H6) emerge. These results suggest that the interaction between deep H2-rich fluids and reduced carbon minerals may be an efficient mechanism for producing abiotic hydrocarbons at the upper mantle. Using diamond anvil cell and high temperature experiments, this work proves that the interaction between deep hydrogen rich fluids and reduced carbon minerals may be an efficient mechanism for producing abiotic hydrocarbons at the upper mantle’s pressures and temperatures.

SUBMITTER: Pena-Alvarez M

PROVIDER: S-EPMC8569197 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Diamond formation from methane hydrate under the internal conditions of giant icy planets.

Project description:Hydrocarbon chemistry in the C-O-H system at high pressure and high temperature is important for modelling the internal structure and evolution of giant icy planets, such as Uranus and Neptune, as their interiors are thought to be mainly composed of water and methane. In particular, the formation of diamond from the simplest hydrocarbon, i.e., methane, under the internal conditions of these planets has been discussed for nearly 40 years. Here, we demonstrate the formation of diamond from methane hydrate up to 3800 K and 45 GPa using a CO2 laser-heated diamond anvil cell combined with synchrotron X-ray diffraction, Raman spectroscopy, and scanning electron microscopy observations. The results show that the process of dissociation and polymerisation of methane molecules to produce heavier hydrocarbons while releasing hydrogen to ultimately form diamond proceeds at milder temperatures (~ 1600 K) and pressures (13-45 GPa) in the C-O-H system than in the C-H system due to the influence of water. Our findings suggest that diamond formation can also occur in the upper parts of the icy mantles of giant icy planets.

| S-EPMC8047023 | biostudies-literature

Development of a Reduced Methane-Hydrogen-Polyoxymethylene Dimethyl Ether Mechanism under Engine-Relevant Conditions.

Project description:Polyoxymethylene dimethyl ethers (PODE n ) have a high cetane number and a high oxygen content, which can effectively reduce the soot emission. In this study, PODE3, methane, and hydrogen were used as the characterization fuel. First, the detailed reaction mechanism of PODE3 and GRI-Mech 3.0 was reduced under engine-relevant conditions by using the reduced methods of the direct relation graph, the directed relation graph with error propagation, the sensitivity analysis, and the reaction pathway analysis. Then, the simplified PODE3 and methane-hydrogen mechanism were coupled and optimized. Finally, the simplified chemical kinetics mechanism of methane-hydrogen-PODE3 (67 species, 260 reactions) was developed. After that, the methane-hydrogen-PODE3 mechanism for methane/hydrogen/PODE3 blend combustion was established, and experimental verification was performed against ignition delay times, laminar flame speeds, and premixed flame species profiles, which showed a good agreement between the predicted and experimental data. Finally, the current mechanism was found to have high reliability and can be coupled to computational fluid dynamics.

| S-EPMC8637598 | biostudies-literature

Synthesis of Highly Crystalline Graphite from Spontaneous Ignition of In Situ Derived Acetylene and Chlorine at Ambient Conditions.

Project description:We exploited a classic chemistry demonstration experiment based on the reaction of acetylene with chlorine to obtain highly crystalline graphite at ambient conditions. Acetylene and chlorine were generated in-situ by the addition of calcium carbide (CaC2) in a concentrated HCl solution, followed by the quick addition of domestic bleach (NaClO). The released gases reacted spontaneously, giving bursts of yellow flame, leaving highly crystalline graphite deposits in the aqueous phase. This was a rather benign alternative towards synthetic graphite, the latter usually being prepared at high temperatures. The synthetic graphite was further utilized to obtain graphene or conductive inks.

| S-EPMC7024288 | biostudies-literature

Synthesis of diamond-like phase from graphite by ultrafast laser driven dynamical compression.

Project description:Rapid variations of the environmental energy caused by ultrashort laser pulses have induced phase transitions in carbon allotropes, therefore bringing the promise of revealing new carbon phases. Here, by exposing polycrystalline graphite to 25 fs laser pulses at 4 J/cm(2) fluence under standard air atmosphere, we demonstrated the synthesis of translucent micrometer-sized structures carrying diamond-like and onion-like carbon phases. Texturized domains of the diamond phase were also identified. Concerning different synthesized carbon forms, pulse superposition and singularities of the thermodynamical process, we pinpoint the synthesis mechanism by the laser-induced subsequent products energetically evolving to attain the diamond-like phase.

| S-EPMC4493556 | biostudies-literature

In Situ X-ray Microscopy Reveals Particle Dynamics in a NiCo Dry Methane Reforming Catalyst under Operating Conditions.

Project description:Herein, we report the synthesis of a ?-Al2O3-supported NiCo catalyst for dry methane reforming (DMR) and study the catalyst using in situ scanning transmission X-ray microscopy (STXM) during the reduction (activation step) and under reaction conditions. During the reduction process, the NiCo alloy particles undergo elemental segregation with Co migrating toward the center of the catalyst particles and Ni migrating to the outer surfaces. Under DMR conditions, the segregated structure is maintained, thus hinting at the importance of this structure to optimal catalytic functions. Finally, the formation of Ni-rich branches on the surface of the particles is observed during DMR, suggesting that the loss of Ni from the outer shell may play a role in the reduced stability and hence catalyst deactivation. These findings provide insights into the morphological and electronic structural changes that occur in a NiCo-based catalyst during DMR. Further, this study emphasizes the need to study catalysts under operating conditions in order to elucidate material dynamics during the reaction.

| S-EPMC7295368 | biostudies-literature

Biological methane production under putative Enceladus-like conditions.

Project description:The detection of silica-rich dust particles, as an indication for ongoing hydrothermal activity, and the presence of water and organic molecules in the plume of Enceladus, have made Saturn's icy moon a hot spot in the search for potential extraterrestrial life. Methanogenic archaea are among the organisms that could potentially thrive under the predicted conditions on Enceladus, considering that both molecular hydrogen (H2) and methane (CH4) have been detected in the plume. Here we show that a methanogenic archaeon, Methanothermococcus okinawensis, can produce CH4 under physicochemical conditions extrapolated for Enceladus. Up to 72% carbon dioxide to CH4 conversion is reached at 50?bar in the presence of potential inhibitors. Furthermore, kinetic and thermodynamic computations of low-temperature serpentinization indicate that there may be sufficient H2 gas production to serve as a substrate for CH4 production on Enceladus. We conclude that some of the CH4 detected in the plume of Enceladus might, in principle, be produced by methanogens.

| S-EPMC5829080 | biostudies-literature

Diamond formation in an electric field under deep Earth conditions.

Project description:Most natural diamonds are formed in Earth's lithospheric mantle; however, the exact mechanisms behind their genesis remain debated. Given the occurrence of electrochemical processes in Earth's mantle and the high electrical conductivity of mantle melts and fluids, we have developed a model whereby localized electric fields play a central role in diamond formation. Here, we experimentally demonstrate a diamond crystallization mechanism that operates under lithospheric mantle pressure-temperature conditions (6.3 and 7.5 gigapascals; 1300° to 1600°C) through the action of an electric potential applied across carbonate or carbonate-silicate melts. In this process, the carbonate-rich melt acts as both the carbon source and the crystallization medium for diamond, which forms in assemblage with mantle minerals near the cathode. Our results clearly demonstrate that electric fields should be considered a key additional factor influencing diamond crystallization, mantle mineral-forming processes, carbon isotope fractionation, and the global carbon cycle.

| S-EPMC7817093 | biostudies-literature

Direct laser writing of nanodiamond films from graphite under ambient conditions.

Project description:Synthesis of diamond, a multi-functional material, has been a challenge due to very high activation energy for transforming graphite to diamond, and therefore, has been hindering it from being potentially exploited for novel applications. In this study, we explore a new approach, namely confined pulse laser deposition (CPLD), in which nanosecond laser ablation of graphite within a confinement layer simultaneously activates plasma and effectively confine it to create a favorable condition for nanodiamond formation from graphite. It is noteworthy that due to the local high dense confined plasma created by transparent confinement layer, nanodiamond has been formed at laser intensity as low as 3.7?GW/cm(2), which corresponds to pressure of 4.4?GPa, much lower than the pressure needed to transform graphite to diamond traditionally. By manipulating the laser conditions, semi-transparent carbon films with good conductivity (several k?/Sq) were also obtained by this method. This technique provides a new channel, from confined plasma to solid, to deposit materials that normally need high temperature and high pressure. This technique has several important advantages to allow scalable processing, such as high speed, direct writing without catalyst, selective and flexible processing, low cost without expensive pico/femtosecond laser systems, high temperature/vacuum chambers.

| S-EPMC4202219 | biostudies-other

Carbonate-hosted microbial communities are prolific and pervasive methane oxidizers at geologically diverse marine methane seep sites.

Project description:At marine methane seeps, vast quantities of methane move through the shallow subseafloor, where it is largely consumed by microbial communities. This process plays an important role in global methane dynamics, but we have yet to identify all of the methane sinks in the deep sea. Here, we conducted a continental-scale survey of seven geologically diverse seafloor seeps and found that carbonate rocks from all sites host methane-oxidizing microbial communities with substantial methanotrophic potential. In laboratory-based mesocosm incubations, chimney-like carbonates from the newly described Point Dume seep off the coast of Southern California exhibited the highest rates of anaerobic methane oxidation measured to date. After a thorough analysis of physicochemical, electrical, and biological factors, we attribute this substantial metabolic activity largely to higher cell density, mineral composition, kinetic parameters including an elevated Vmax, and the presence of specific microbial lineages. Our data also suggest that other features, such as electrical conductance, rock particle size, and microbial community alpha diversity, may influence a sample's methanotrophic potential, but these factors did not demonstrate clear patterns with respect to methane oxidation rates. Based on the apparent pervasiveness within seep carbonates of microbial communities capable of performing anaerobic oxidation of methane, as well as the frequent occurrence of carbonates at seeps, we suggest that rock-hosted methanotrophy may be an important contributor to marine methane consumption.

| S-EPMC8237665 | biostudies-literature

Electron paramagnetic resonance microscopy using spins in diamond under ambient conditions.

Project description:Magnetic resonance spectroscopy is one of the most important tools in chemical and bio-medical research. However, sensitivity limitations typically restrict imaging resolution to ~?10?µm. Here we bring quantum control to the detection of chemical systems to demonstrate high-resolution electron spin imaging using the quantum properties of an array of nitrogen-vacancy centres in diamond. Our electron paramagnetic resonance microscope selectively images electronic spin species by precisely tuning a magnetic field to bring the quantum probes into resonance with the external target spins. This provides diffraction limited spatial resolution of the target spin species over a field of view of 50?×?50?µm2 with a spin sensitivity of 104 spins per voxel or ?100?zmol. The ability to perform spectroscopy and dynamically monitor spin-dependent redox reactions at these scales enables the development of electron spin resonance and zepto-chemistry in the physical and life sciences.Electron paramagnetic resonance spectroscopy has important scientific and medical uses but improving the resolution of conventional methods requires cryogenic, vacuum environments. Simpson et al. show nitrogen vacancy centres can be used for sub-micronmetre imaging with improved sensitivity in ambient conditions.

| S-EPMC5587709 | 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