Activated carbon-based molecular sieves were synthetized, characterized and their kinetics of adsorption evaluated to be used in separation processes CO2/CH4 mixtures. Polyurethane (PU) foams as carbon precursors the PU-derived carbons physical activated with CO2. All samples present a preferential CO2 over methane kinetic experiments. Samples at 800 ºC during 6 h exhibited highest selectivity ...

One explanation for the abrupt increases in atmospheric CH4, that occurred repeatedly during the last glacial cycle involves clathrate destabalization events. Because marine clathrates have a distinct deuterium/hydrogen (D/H) isotope ratio, any such destabilization event should cause the D/H ratio of atmospheric CH4 (deltaD(CH4)) to increase. Analyses of air trapped in the ice from the second G...

We present a global methane modelling study assessing the sensitivity of Arctic atmospheric CH4 mole fractions, δC-CH4 and δD-CH4 to uncertainties in Arctic methane sources. Model simulations include methane tracers tagged by source and isotopic composition and are compared with atmospheric data at four northern high-latitude measurement sites. We find the model’s ability to capture the magnitu...

We report a molecular beam study of the effect of vibrational excitation on the physisorption of methane on a Pt(111) surface. Our experiments use a continuous molecular beam of CH4, prepared in its antisymmetic C−H stretch mode ν3 by infrared laser pumping via rapid adiabatic passage. Physisorbed CH4(ads) is detected on a Pt(111) surface by reflection absorption infrared spectroscopy. At a sur...

Methane (CH4) emissions via emergent aquatic macrophytes can contribute substantially to the global CH4 balance. We addressed temporal variability in CH4 flux by using the static chamber approach to quantify fluxes from plots dominated by two species considered to differ in flux transport mechanisms (Phragmites australis, Carex rostrata). Temporal variability in daily mean emissions from early ...

We conducted irradiation experiments with riverine, estuarine, and marine water samples to investigate the possibility of photochemical methane (CH4) formation. CH4 photoproduction was undetectable under oxic conditions or in the absence of methyl radical precursors indicating that its photochemical formation is negligible in the present ocean. Significant photochemical CH4 production was obser...

Focused electron beam induced deposition (FEBID) is a versatile tool for the direct-write fabrication of nanostructures on surfaces. However, FEBID nanostructures are usually highly contaminated by carbon originating from the precursor used in the process. Recently, it was shown that platinum nanostructures produced by FEBID can be efficiently purified by electron irradiation in the presence of...

Grand canonical Monte Carlo (GCMC) simulations of CO2 and CH4 sorption and separation were performed in dia-7i-1-Co, a metal-organic material (MOM) consisting of a 7-fold interpenetrated net of Co(2+) ions coordinated to 4-(2-(4-pyridyl)ethenyl)benzoate linkers. This MOM shows high affinity toward CH4 at low loading due to the presence of narrow, close fitting, one-dimensional hydrophobic chann...

The dynamics of carburization of Mo-oxo precursors exchanged onto H-ZSM-5 strongly influence initial induction periods and steady-state rates during catalytic pyrolysis of CH4 to alkenes and arenes at 900-1000 K. The effects of co-reactants and of activating conditions were examined by on-line time-resolved mass spectrometric analysis of effluent streams using rigorous analyses to account for e...

The Sanjiang Plain (SJP), one of the major rice producing regions in China, is an important source of methane (CH4) emissions. However, there have been large uncertainties in the estimates of CH4 emissions from this area during the past few years. In this study, we estimated CH4 emissions using a process-based model derived by rice area, CH4 flux, land surface temperature (LST), and the ratio o...