Methyl Radicals in Oxidative Coupling of Methane Directly Confirmed by Synchrotron VUV Photoionization Mass Spectroscopy

Methyl Radicals in Oxidative Coupling of Methane Directly Confirmed by Synchrotron VUV Photoionization Mass Spectroscopy

Gas-phase methyl radicals have been long proposed as the key intermediate in catalytic oxidative coupling of methane, but the direct experimental evidence still lacks. Here, employing synchrotron VUV photoionization mass spectroscopy, we have directly observed the formation of gas-phase methyl radicals during oxidative coupling of methane catalyzed by Li/MgO catalysts. The concentration of gas-...

Miniplant-Scale Analysis of Oxidative Coupling of Methane Process

For more than three decades, Oxidative Coupling of Methane (OCM) process has been comprehensively investigated as an attractive alternative for the commercially available ethylene production technologies such as ethane and naphtha cracking. Developing a suitable catalyst and proper reactor feeding policy, reviewing and deploying the efficient methods in the separation and purification of the un...

Mass-analyzed threshold ionization (MATI) spectroscopy of atoms and molecules using VUV synchrotron radiation.

Mass-analyzed threshold ionization (MATI) spectroscopy using synchrotron radiation (Advanced Light Source, Lawrence Berkeley National Laboratory) has been performed for Ar, N(2), O(2), N(2)O, H(2)O, C(2)H(2), and C(6)H(6). MATI allows for a better determination of ionization energies compared to those derived from photoionization efficiency curves traditionally used in synchrotron photoionizati...

Fragment-Free Mass Spectrometric Analysis with Jet Cooling/VUV Photoionization.

We show that it is possible to obtain fragment-free mass spectra of large molecules by a combination of laser desorption, jet cooling, and VUV single-photon photoionization. The ability to obtain parent molecular masses is particularly important for the analysis of mixtures, such as combinations of fully saturated hydrocarbons. By varying the cooling conditions, we can also achieve partial frag...

Rate and selectivity enhancements mediated by OH radicals in the oxidative coupling of methane catalyzed by Mn/Na2WO4/SiO2.