The Role of CO2for the Gas-Phase O2Oxidation of Alkylaromatics to Aldehydes

2002 ◽  
pp. 112-128 ◽  
Author(s):  
Jin S. Yoo
Keyword(s):  
Gas Phase

scholarly journals The role of radiolysis in the modelling of C2H4O2 isomers and dimethyl ether in cold dark clouds

2020 ◽  
Vol 500 (3) ◽  
pp. 3414-3424
Author(s):  
Alec Paulive ◽  
Christopher N Shingledecker ◽  
Eric Herbst
Keyword(s):  
Gas Phase ◽  
Dimethyl Ether ◽  
Recent Observation ◽  
Cosmic Ray ◽  
Thermal Method ◽  
Dark Clouds ◽  
Ice Surface ◽  
Dust Grain ◽  
Complex Organic

ABSTRACT Complex organic molecules (COMs) have been detected in a variety of interstellar sources. The abundances of these COMs in warming sources can be explained by syntheses linked to increasing temperatures and densities, allowing quasi-thermal chemical reactions to occur rapidly enough to produce observable amounts of COMs, both in the gas phase, and upon dust grain ice mantles. The COMs produced on grains then become gaseous as the temperature increases sufficiently to allow their thermal desorption. The recent observation of gaseous COMs in cold sources has not been fully explained by these gas-phase and dust grain production routes. Radiolysis chemistry is a possible non-thermal method of producing COMs in cold dark clouds. This new method greatly increases the modelled abundance of selected COMs upon the ice surface and within the ice mantle due to excitation and ionization events from cosmic ray bombardment. We examine the effect of radiolysis on three C2H4O2 isomers – methyl formate (HCOOCH3), glycolaldehyde (HCOCH2OH), and acetic acid (CH3COOH) – and a chemically similar molecule, dimethyl ether (CH3OCH3), in cold dark clouds. We then compare our modelled gaseous abundances with observed abundances in TMC-1, L1689B, and B1-b.

Role of solid- and gas-phase interactions in the coaction of the oxides in MnO2 + PbO and MnO2 + V2O5 compositions activating the thermal oxidation of GaAs

2007 ◽  
Vol 52 (10) ◽  
pp. 1498-1502 ◽  
Author(s):  
V. F. Kostryukov ◽  
V. R. Pshestanchik ◽  
I. A. Donkareva ◽  
B. L. Agapov ◽  
S. I. Lopatin ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Gas Phase

Formation of OH radicals in the gas phase ozonolysis of alkenes: the unexpected role of carbonyl oxides

1996 ◽  
Vol 252 (3-4) ◽  
pp. 221-229 ◽  
Author(s):  
Roland Gutbrod ◽  
Ralph N. Schindler ◽  
Elfi Kraka ◽  
Dieter Cremer
Keyword(s):  
Gas Phase ◽  
Oh Radicals ◽  
Carbonyl Oxides

scholarly journals Efficient utilization of renewable feedstocks: the role of catalysis and process design

2017 ◽  
Vol 376 (2110) ◽  
pp. 20170064 ◽  
Author(s):  
Regina Palkovits ◽  
Irina Delidovich
Keyword(s):  
Elevated Temperature ◽  
Gas Phase ◽  
Process Design ◽  
Circular Economy ◽  
Paradigm Shift ◽  
Efficient Utilization ◽  
Polar Solvents ◽  
Platform Chemicals ◽  
Renewable Feedstocks

Renewable carbon feedstocks such as biomass and CO 2 present an important element of future circular economy. Especially biomass as highly functionalized feedstock provides manifold opportunities for the transformation into attractive platform chemicals. However, this change of the resources requires a paradigm shift in refinery design. Fossil feedstocks are processed in gas phase at elevated temperature. In contrast, biorefineries are based on processes in polar solvents at moderate conditions to selectively deoxygenate the polar, often thermally instable and high-boiling molecules. Here, challenges of catalytic deoxygenation, novel strategies for separation and opportunities provided at the interface to biotechnology are discussed in form of showcases. This article is part of a discussion meeting issue ‘Providing sustainable catalytic solutions for a rapidly changing world’.

scholarly journals Role of (H2O)n (n = 1–2) in the Gas-Phase Reaction of Ethanol with Hydroxyl Radical: Mechanism, Kinetics, and Products

ACS Omega ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 5805-5817 ◽  
Author(s):  
Li Xu ◽  
Narcisse T. Tsona ◽  
Shanshan Tang ◽  
Junyao Li ◽  
Lin Du
Keyword(s):  
Hydroxyl Radical ◽  
Gas Phase ◽  
Radical Mechanism ◽  
Phase Reaction ◽  
Gas Phase Reaction

Di-imide: Some Physical and Chemical Properties, and the Kinetics and Stoichiometry of the Gas-phase Decomposition

1973 ◽  
Vol 51 (21) ◽  
pp. 3605-3619 ◽  
Author(s):  
C. Willis ◽  
R. A. Back
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Chemical Properties ◽  
Phase Decomposition ◽  
Important Intermediate ◽  
Long Lifetime ◽  
Physical And Chemical ◽  
Text Formation ◽  
Kinetics Of

Preparation of di-imide by passing hydrazine vapor through a microwave discharge yields mixtures with NH3 containing typically about 15% N2H2, estimated from the gases evolved on decomposition. The behavior of the mixture (which melts at −65 °C) on warming from −196 to −30 °C suggests a strong interaction between the components. Measurements of magnetic susceptibility and e.p.r. experiments showed that N2H2 is not strongly paramagnetic, which with other observations points to a singlet rather than a triplet ground-state.Di-imide can be vaporized efficiently, together with NH3, by rapid warming, and the vapor is surprisingly long-lived, with a typical half-life of several minutes at room temperature. The near-u.v. (3200–4400 Å) absorption spectrum of the vapor was photographed; it shows well-defined but diffuse bands, with εmax = 6(± 3) at 3450 Å.Di-imide decomposes at room temperature in two ways:[Formula: see text][Formula: see text]Formation of NH3 was not observed but cannot be ruled out. The decomposition of the vapor is complicated by a sizeable and variable decomposition that occurs rapidly during the vaporization. The stoichiometry of this and the vapor-phase decomposition depends on total pressure and di-imide concentration. The kinetics of the decomposition of the vapor were studied from 22 to 200 °C by following the disappearance of N2H2 by absorption of light at 3450 Å, or the formation of N2H4 by absorption at 2400 Å, and by mass spectrometry. The kinetics are complex and can be either first- or second-order, or mixed, depending on surface conditions. The effect of olefin additives on the decomposition was studied, and is also complex.Mechanisms for the decomposition are discussed, including the possible role of trans-cis isomerization. The relatively long lifetime found for di-imide in the gas phase suggests that it may be an important intermediate in many reactions of hydronitrogen systems.

Sign in / Sign up

Export Citation Format

Share Document