Thermochemical and Kinetic Analysis of the Thermal Decomposition of Monomethylhydrazine: An Elementary Reaction Mechanism†

2007 ◽  
Vol 111 (19) ◽  
pp. 3748-3760 ◽  
Author(s):  
Hongyan Sun ◽  
Chung K. Law
Keyword(s):  
Thermal Decomposition ◽  
Reaction Mechanism ◽  
Kinetic Analysis ◽  
Elementary Reaction

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.

scholarly journals Kinetic Analysis of the Thermal Decomposition of Iron(III) Phosphates: Fe(NH3)2PO4 and Fe(ND3)2PO4

2020 ◽  
Vol 21 (3) ◽  
pp. 781
Author(s):  
Isabel Iglesias ◽  
José A. Huidobro ◽  
Belén F. Alfonso ◽  
Camino Trobajo ◽  
Aránzazu Espina ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Analysis ◽  
Room Temperature ◽  
Isoconversional Methods ◽  
Iron Phosphate ◽  
Dihydrogen Phosphate ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Group A

The hydrothermal synthesis and both the chemical and structural characterization of a diamin iron phosphate are reported. A new synthetic route, by using n-butylammonium dihydrogen phosphate as a precursor, leads to the largest crystals described thus far for this compound. Its crystal structure is determined from single-crystal X-ray diffraction data. It crystallizes in the orthorhombic system (Pnma space group, a = 10.1116(2) Å, b = 6.3652(1) Å, c = 7.5691(1) Å, Z = 4) at room temperature and, below 220 K, changes towards the monoclinic system P21/n, space group. The in situ powder X-ray thermo-diffraction monitoring for the compound, between room temperature and 1100 K, is also included. Thermal analysis shows that the solid is stable up to ca. 440 K. The kinetic analysis of thermal decomposition (hydrogenated and deuterated forms) is performed by using the isoconversional methods of Vyazovkin and a modified version of Friedman. Similar values for the kinetic parameters are achieved by both methods and they are checked by comparing experimental and calculated conversion curves.

Elementary reaction mechanism of diamond growth from acetylene

1994 ◽  
Vol 98 (1) ◽  
pp. 8-11 ◽  
Author(s):  
Sergei Skokov ◽  
Brian Weiner ◽  
Michael Frenklach
Keyword(s):  
Reaction Mechanism ◽  
Elementary Reaction ◽  
Diamond Growth

Elementary Reaction Mechanism for Benzene Oxidation in Supercritical Water†

2000 ◽  
Vol 104 (45) ◽  
pp. 10576-10586 ◽  
Author(s):  
Joanna L. DiNaro ◽  
Jack B. Howard ◽  
William H. Green ◽  
Jefferson W. Tester ◽  
Joseph W. Bozzelli
Keyword(s):  
Reaction Mechanism ◽  
Supercritical Water ◽  
Elementary Reaction ◽  
Benzene Oxidation

Kinetic Analysis of Overlapping Multistep Thermal Decomposition of 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105)

2018 ◽  
Vol 122 (45) ◽  
pp. 25999-26006 ◽  
Author(s):  
Qian Yu ◽  
Yu Liu ◽  
Heliang Sui ◽  
Jie Sun ◽  
Jinshan Li
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Analysis

scholarly journals Reaction of a satirically hindered iron(III) porphyrin with peroxyacetic acid: Degradation kinetics

2005 ◽  
Vol 70 (8-9) ◽  
pp. 1105-1111 ◽  
Author(s):  
P. Prakash ◽  
Mary Francisca
Keyword(s):  
Reaction Mechanism ◽  
Spectroscopic Study ◽  
Kinetic Analysis ◽  
Peracetic Acid ◽  
Degradation Kinetics ◽  
Oxidative Degradation ◽  
Peroxyacetic Acid ◽  
Porphyrin Ligand ◽  
Uv Visible ◽  
Reversible Formation

A kinetic analysis of the reaction between peracetic acid (AcOOH), and tetrakis (pentafluorophenyl) - 21H, 23H-porphine iron(III) chloride Fe(F20TPP)Cl, in acetonitrile showed that the peracetic acid oxidatively destroys Fe(F20TPP)Cl. This is in contrast to an assumption that the oxidative degradation of metalloporphyrins can be prevented by the introduction of electron-withdrawing substituents into the phenyl groups of the porphyrin ligand. A UV-visible spectroscopic study showed a degree of macro cycle destruction of the tetrapyrrole conjucation of the metalloporphyrin. The degradation takes place via oxoperferryl species. The first step of the reaction mechanism is the reversible formation of an adduct ?X? (k1/k-1) between Fe(F20TPP)Cl and peracetic acid, followed by an irreversible step (k2) for the formation of oxoperferryl species.

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