Hicks, Jason M.
Computational Studies Of Oxides Relevant To Clean Energy, Catalytic Processing Of Renewables, And Biological Systems.
Degree: PhD, Chemistry, 2018, University of North Dakota
Computational chemistry has grown into a large field and is continuing to grow every year in both number and variety of applications. This dissertation will give a few such applications relevant to cleaner energy production from coal, catalytic degradation of renewable agricultural and forest waste into valuable chemicals, and extending the reach of electronic structure methods to systems of biological and macromolecular interest. The first two studies presented in this dissertation are concerned with the remediation of trace elements released into the environment through the combustion of coal for power production. In flue gases, arsenic and antimony exists most often as oxides. Despite the prevalence and importance of remediating these oxides, critical information on the thermodynamics of plausible intermediates and transition states in reaction pathways have been missing prior to these studies. Several of the intermediates, and essentially all transition states, were found to be electronically multiconfigurational for the arsenic oxides. In this work, the electronic structures of several oxides of arsenic, AsxOy, where x = 1, 2 and y = 1-5, were investigated using the second-order generalized van Vleck variant of multireference perturbation theory (GVVPT2), using the cc-pVTZ basis set, with comparison to multi-reference configuration interaction (MRCISD) and the linked completely renormalized coupled cluster through perturbative triple excitations (CR-CCSD(T)L or CR-CC(2,3)) when relevant. Calculated oxidation reaction energies for the formation of AsO2 and AsO3 from AsO were predicted to be energetically favorable and formation energies of the lowest energy compounds containing two metalloid atoms, called dimers for brevity, from the monomers were also predicted to be energetically favorable. The energetics of the monomers, five isomers of As2O3 and eleven isomers of As2O5 were characterized using a composite methodology along with the key transition states between the isomers. Geometry optimizations as well as harmonic vibrational frequencies of AsxOy were obtained at the B3LYP/6-311G* level of theory and gave satisfactory agreement with experimental data when available. It was discovered that several isomers of As2O3 and As2O5 have comparable energies and relatively low barrier heights. Therefore, we expect these isomers to be chemically relevant.
The antimony oxides were also found to be electronically multiconfigurational. The electronic structures of several antimony oxides, SbxOy, where x = 1, 2 and y = 1-5, were investigated using GVVPT2 and the SBD-aug-cc-pVTZ basis set. The oxidation reaction energies of elemental antimony toward the formation of SbO and SbO2 was found to be energetically favorable, while the further oxidation of those species to SbO3 was found to be unfavorable. It was found that the accretion of the monomers into Sb2O3 was highly energetically favorable at both the B3LYP/SBD-aug-cc-pVTZ and GVVPT2/SBD-aug-cc-pVTZ//B3LYP/SBD-aug-cc-pVTZ levels of theory. However,…
Advisors/Committee Members: Mark R. Hoffmann.
Subjects/Keywords: Cu2O2; electronic structure theory; GVVPT2; lignin; metalloid oxides; multireference perturbation theory
to Zotero / EndNote / Reference
APA (6th Edition):
Hicks, J. M. (2018). Computational Studies Of Oxides Relevant To Clean Energy, Catalytic Processing Of Renewables, And Biological Systems. (Doctoral Dissertation). University of North Dakota. Retrieved from https://commons.und.edu/theses/2232
Chicago Manual of Style (16th Edition):
Hicks, Jason M. “Computational Studies Of Oxides Relevant To Clean Energy, Catalytic Processing Of Renewables, And Biological Systems.” 2018. Doctoral Dissertation, University of North Dakota. Accessed October 21, 2019.
MLA Handbook (7th Edition):
Hicks, Jason M. “Computational Studies Of Oxides Relevant To Clean Energy, Catalytic Processing Of Renewables, And Biological Systems.” 2018. Web. 21 Oct 2019.
Hicks JM. Computational Studies Of Oxides Relevant To Clean Energy, Catalytic Processing Of Renewables, And Biological Systems. [Internet] [Doctoral dissertation]. University of North Dakota; 2018. [cited 2019 Oct 21].
Available from: https://commons.und.edu/theses/2232.
Council of Science Editors:
Hicks JM. Computational Studies Of Oxides Relevant To Clean Energy, Catalytic Processing Of Renewables, And Biological Systems. [Doctoral Dissertation]. University of North Dakota; 2018. Available from: https://commons.und.edu/theses/2232