A Computational Study of the Dissolution of Aluminosilicate Minerals

Open Access
Author:
Morrow, Christin Palombo
Graduate Program:
Chemistry
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
August 15, 2008
Committee Members:
  • Karl Todd Mueller, Thesis Advisor
  • Barbara Jane Garrison, Thesis Advisor
Keywords:
  • aluminosilicate
  • ab-initio
  • mechanism
  • dissolution
Abstract:
The reactions of aluminosilicate clusters with water are investigated using ab-initio calculations. Reaction mechanisms for silicon terminated, Si-Obr-Al, sites as well as aluminum terminated, Al-Obr-Si, sites were determined using B3LYP/6-311+G(d,p) calculations. The calculated barrier heights for protonated and neutral Al-Obr-Si sites are predicted to be lower than those for Si-Obr-Si and Si-Obr-Al sites which mimics the dissolution of these minerals, and the Si-Obr-Al dissolution reactions proceeded in fundamentally the same fashion as those for Si-Obr-Si [S. Nangia and B. J. Garrison, J. Phys. Chem. A 2008, 112, 2027]. The barrier heights for the rate determining step for these reactions are calculated using the B3LYP, PBE1PBE, and M05-2X functionals in combination with the 6-311+G(d,p) and MG3S basis sets, and trends seen in the mechanistic calculations are repeated with each computational method.