scholarly journals Hydrogenation of CO2 Promoted by Silicon-Activated H2S: Origin and Implications

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 50
Author(s):  
Xing Liu
Keyword(s):  
Low Temperatures ◽  
Underlying Mechanism ◽  
Reactive Species ◽  
Co2 Hydrogenation ◽  
Usual Method ◽  
Title Reaction ◽  
Hydrogenation Of Co2 ◽  
Hydrogenation Reactions

Unlike the usual method of COx (x = 1, 2) hydrogenation using H2 directly, H2S and HSiSH (silicon-activated H2S) were selected as alternative hydrogen sources in this study for the COx hydrogenation reactions. Our results suggest that it is kinetically infeasible for hydrogen in the form of H2S to transfer to COx at low temperatures. However, when HSiSH is employed instead, the title reaction can be achieved. For this approach, the activation of CO2 is initiated by its interaction with the HSiSH molecule, a reactive species with both a hydridic Hδ− and protonic Hδ+. These active hydrogens are responsible for the successive C-end and O-end activations of CO2 and hence the final product (HCOOH). This finding represents a good example of an indirect hydrogen source used in CO2 hydrogenation through reactivity tuned by silicon incorporation, and thus the underlying mechanism will be valuable for the design of similar reactions.

scholarly journals Experiments at very low temperatures obtained by the magnetic method I—The production of the low temperatures

1935 ◽  
Vol 149 (866) ◽  
pp. 152-176 ◽  
Keyword(s):  
Liquid Helium ◽  
Vapour Pressure ◽  
Low Temperatures ◽  
Usual Method ◽  
Magnetic Method ◽  
Isothermal Magnetization

The lowest limit of temperature obtainable by the hitherto usual method of evaporating liquid helium lies at about 0⋅7º. At this temperature the vapour pressure of helium is already so small that it does not seem possible to proceed to appreciably lower temperatures in this way. In the course of last year the first successful experiments in attaining still lower temperatures were carried out using the magnetic method proposed by Debye and Giauque. This method is based on the possibility of diminishing considerably the entropy of some paramagnetic salts by isothermal magnetization. The subsequent demagnetization, if carried out adiabatically, then results in a lowering of the temperature.

Exploring reactive species of chlorocarbons and oxygen atom generation at low temperatures using electron gun assembly

2019 ◽  
Vol 525 ◽  
pp. 110389
Author(s):  
N. Ramanathan ◽  
K. Sundararajan ◽  
Shubhra Sarkar ◽  
P.K. Sruthi
Keyword(s):  
Oxygen Atom ◽  
Low Temperatures ◽  
Reactive Species ◽  
Electron Gun

scholarly journals Ultradispersed Mo/TiO2 catalysts for CO2 hydrogenation to methanol

2021 ◽  
Author(s):  
Thomas Len ◽  
Mounib Bahri ◽  
Ovidiu Ersen ◽  
Yaya Lefkir ◽  
Luis Cardenas ◽  
...  
Keyword(s):  
Gas Phase ◽  
Co2 Hydrogenation ◽  
Hydrogenation Of Co2 ◽  
Crucial Effect ◽  
Effect Of The Support

Mo/TiO2 catalysts with atomic dispersion of molybdenum appear active and stable in the gas-phase hydrogenation of CO2. The comparison between various titania materials shows a crucial effect of the support...

scholarly journals Temperature-(208–318 K) and pressure-(18–696 Torr) dependent rate coefficients for the reaction between OH and HNO<sub>3</sub>

2018 ◽  
Vol 18 (4) ◽  
pp. 2381-2394 ◽  
Author(s):  
Katrin Dulitz ◽  
Damien Amedro ◽  
Terry J. Dillon ◽  
Andrea Pozzer ◽  
John N. Crowley
Keyword(s):  
Cross Sections ◽  
Pressure Dependence ◽  
Low Temperatures ◽  
Room Temperature ◽  
Rate Coefficients ◽  
Title Reaction ◽  
Data Set ◽  
Dependent Rate ◽  
Temperature And Pressure

Abstract. Rate coefficients (k5) for the title reaction were obtained using pulsed laser photolytic generation of OH coupled to its detection by laser-induced fluorescence (PLP–LIF). More than 80 determinations of k5 were carried out in nitrogen or air bath gas at various temperatures and pressures. The accuracy of the rate coefficients obtained was enhanced by in situ measurement of the concentrations of both HNO3 reactant and NO2 impurity. The rate coefficients show both temperature and pressure dependence with a rapid increase in k5 at low temperatures. The pressure dependence was weak at room temperature but increased significantly at low temperatures. The entire data set was combined with selected literature values of k5 and parameterised using a combination of pressure-dependent and -independent terms to give an expression that covers the relevant pressure and temperature range for the atmosphere. A global model, using the new parameterisation for k5 rather than those presently accepted, indicated small but significant latitude- and altitude-dependent changes in the HNO3 ∕ NOx ratio of between −6 and +6 %. Effective HNO3 absorption cross sections (184.95 and 213.86 nm, units of cm2 molecule−1) were obtained as part of this work: σ213.86  =  4.52−0.12+0.23  ×  10−19 and σ184.95  =  1.61−0.04+0.08  ×  10−17.

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