Gas-surface reactions of nitrate radicals with vinyl-terminated self-assembled monolayers

2014 ◽  
Vol 16 (31) ◽  
pp. 16659-16670 ◽  
Author(s):  
Yafen Zhang ◽  
Robert C. Chapleski ◽  
Jessica W. Lu ◽  
Thomas H. Rockhold ◽  
Diego Troya ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Reaction Kinetics ◽  
Gas Phase ◽  
Surface Reactions ◽  
Interfacial Reactions ◽  
Self Assembled Monolayers ◽  
Probable Reaction Mechanism ◽  
Nitrate Radicals ◽  
Assembled Monolayers ◽  
Probable Reaction

Interfacial reactions between gas-phase nitrate radicals, a key nighttime atmospheric oxidant, and a model unsaturated organic surface have been investigated to determine the reaction kinetics and probable reaction mechanism.

Oscillation system of Belousov-Zhabotinskii type in presence of Cl- ions

1986 ◽  
Vol 51 (12) ◽  
pp. 2693-2701 ◽  
Author(s):  
Marta Mrákavová ◽  
Ľudovít Treindl
Keyword(s):  
Reaction Mechanism ◽  
Ethyl Ester ◽  
Reaction System ◽  
Oscillation System ◽  
Low Concentration ◽  
Redox Catalyst ◽  
Probable Reaction Mechanism ◽  
Oxobutanoic Acid ◽  
Probable Reaction

A modified Belousov-Zhabotinskii oscillation system involving ethyl ester of 3-oxobutanoic acid and Fe(phen)32+ - Fe(phen)33+ as redox catalyst is remarkable in that it shows an oxygen-induced excitability. The oscillating state, involving 4-5 oscillations in the absorbancy of Fe(phen)32+ ions, comes soon to its end but can be restored by shaking the reaction system, thus incresing the transport of oxygen from the air. This phenomenon is not influenced by Cl- ions in a low concentration, but if this is equal to 10-3 mol dm-3 or higher, no oscillations are observed, the increase of the concentration of Fe(phen)32+ ions is autocatalytic in character and can be reproduced several times by shaking or stirring the solution. These phenomena are discussed in terms of a probable reaction mechanism.

Effect of Co-precursor Maliec Anhydride on the Thermal Decomposition of Acetyl Ferrocene: A Reaction Kinetic Analysis

2019 ◽  
Vol 9 (1) ◽  
pp. 22-35
Author(s):  
Bratati Das ◽  
Ashis Bhattacharjee
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Reaction Mechanism ◽  
Kinetic Analysis ◽  
Reaction Rate ◽  
Reaction Kinetic ◽  
Step Process ◽  
Probable Reaction Mechanism ◽  
Probable Reaction ◽  
Reaction Atmosphere

Background: Thermal decomposition of iron-bearing organometallic complex acetyl ferrocene, (C5H4COCH3)Fe(C5H5), leads to hematite (α-Fe2O3) nanoparticles. Presence of maliec anhydride, C4H2O3 as co-precursor during thermal decomposition modifies the size of the particles as well as the quantity of the reaction product significantly. Objective: Kinetic analysis of the solid-state thermal reaction of acetyl ferrocene in the presence of varying amount of co-precursor maliec anhydride under inert reaction atmosphere has been studied in order to understand the reaction mechanism involved behind the formation of hematite and the role of co-precursor in the reaction process. For this purpose, reaction kinetic analysis of three mixtures of acetyl ferrocene and maliec anhydride has been carried out. Methods: Thermogravimetry under non-isothermal protocol with multiple heating rates has been employed. The data are analyzed using model-free iso-conversional kinetic techniques to estimate the activation energy of reaction and reaction rate. The most-probable reaction mechanism has been identified by master plot method. The kinetic triplets (activation energy, reaction rate, most probable reaction mechanism function) have been employed to estimate the thermodynamic triplets (ΔS, ΔH and ΔG). Observations: Acetyl Ferrocene (AFc) undergoes thermal decomposition in a four-step process leaving certain residual mass whereas maliec anhydride (MA) undergoes complete mass loss owing to melting followed by evaporation. In contrast, the (AFc1-x-MAx) mixtures undergo thermal decomposition through a two-step process, and the decompositions are completed at much lower temperatures than that in AFc. The estimated activation energy and reaction rate values are found strongly dependent on the extent of conversion as well as on the extent of mixing. Introduction of MA in the solid reaction atmosphere of AFc in one hand reduces the activation energy required by AFc to undergo thermal decomposition and the reaction rate, while on the other hand varies the nature of reaction mechanism involved. Results: The range of reaction rate values estimated for the mixtures indicate that the activated complexes during Step-I of thermal decomposition may be treated as ‘loose’ complex whereas ‘tight’ complex for the Step-II. From the estimated entropy values, thermal process of (AFc1-x-MAx) mixture for Steps I and II may be interpreted as ‘‘slow’’ stage. Conclusion: Variation of Gibb’s free energy with the fraction of maliec anhydride in the mixtures for Step-I and II indicate that the thermal processes of changing the corresponding activated complexes are non-spontaneous at room temperature.

The 1,4-phenylenediisocyanide dimer: gas-phase properties and insights into organic self-assembled monolayers

2010 ◽  
Vol 12 (1) ◽  
pp. 82-96 ◽  
Author(s):  
Ryan P. Steele ◽  
Robert A. DiStasio Jr ◽  
Martin Head-Gordon ◽  
Yan Li ◽  
Giulia Galli
Keyword(s):  
Gas Phase ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Phase Properties

Rapid Evaluation and Screening of Interfacial Reactions on Self-Assembled Monolayers

Langmuir ◽  
2007 ◽  
Vol 23 (23) ◽  
pp. 11826-11835 ◽  
Author(s):  
Jing Li ◽  
Parvinder S. Thiara ◽  
Milan Mrksich
Keyword(s):  
Interfacial Reactions ◽  
Self Assembled Monolayers ◽  
Rapid Evaluation ◽  
Assembled Monolayers ◽  
Self Assembled

Gas-Phase Photocatalytic Degradation of Trichloroethylene -Relation with Photochemical Reactions

2002 ◽  
Vol 5 (2) ◽  
Author(s):  
Masayuki Murabayashi ◽  
Kiminori Itoh ◽  
Kouichi Kawamura
Keyword(s):  
Reaction Mechanism ◽  
Photocatalytic Degradation ◽  
Gas Phase ◽  
Photochemical Reaction ◽  
Surface Reactions ◽  
Photochemical Reactions ◽  
Degradation Reactions ◽  
Organic Chlorine ◽  
Degradation Reaction ◽  
Photocatalytic Reactions

AbstractApplications of photocatalytic reactions are now being developed widely for various purposes. These reactions have been especially successful in the remediation of groundwater and soil polluted with organic chlorine compounds. The degradation reactions of these compounds in the gas phase progress fast, but the reaction mechanism is not yet well understood. For example, some unusual phenomena, seen in the effect of the pre-illumination of photocatalysts and that of repeated reactions, have been reported, but the acceleration of the reactions has not been explained based on the surface reactions. For that reason, we studied photochemical reactions and compared them with photocatalytic reactions. We explain the large acceleration of photocatalytic degradation of trichloroethylene (TCE) in a repeated reaction by taking photochemical reaction into consideration. We also explain the very fast degradation reaction of TCE based on the present results.

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