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Reaction Kinetics and Combustion Dynamics of I4O9 and Aluminum Mixtures
Published on: November 7, 2016
Kinetics of Al + H2O reaction: theoretical study
Alexander Sharipov1, Nataliya Titova, Alexander Starik
1Central Institute of Aviation Motors, Scientific Educational Centre Physical-Chemical Kinetics and Combustion, Moscow, Russia.
The Journal of Physical Chemistry. A
|April 8, 2011
Summary
This study investigates the reaction between aluminum (Al) atoms and water (H2O) molecules. Quantum chemical calculations reveal the reaction proceeds in two steps, with the primary pathway involving AlOH formation, not direct HAlOH.
Area of Science:
- Physical Chemistry
- Quantum Chemistry
- Chemical Kinetics
Background:
- The reaction between aluminum atoms and water is crucial in various chemical processes.
- Understanding the reaction mechanism and kinetics is essential for predicting outcomes in systems involving Al and H2O.
Purpose of the Study:
- To investigate the reaction mechanism of an aluminum atom in its ground electronic state with a water molecule.
- To calculate activation barriers and estimate rate constants for the elementary reaction channels.
- To clarify the reaction pathway contributing to experimentally measured rate constants.
Main Methods:
- Quantum chemical calculations using B3LYP/6-311+G(3df,2p), CBS-QB3, and G3 levels of theory.
- Potential energy surface examination to understand reaction pathways.
- Canonical variational theory to estimate rate constants.
Main Results:
- The Al + H2O reaction proceeds via a two-step mechanism: Al + H2O → AlOH + H, followed by AlOH + H → AlO + H2.
- Activation barriers for these steps were calculated.
- Experimental rate constants align with the Al + H2O → AlOH + H pathway.
- Direct HAlOH formation is negligible below 100 atm.
Conclusions:
- The reaction of Al with H2O is a complex, multi-step process.
- The Al + H2O → AlOH + H pathway dominates the reaction kinetics under typical experimental conditions.
- Theoretical calculations provide valuable insights into the reaction mechanism and rate constants.
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