Bagusetty, Abhishek
(2020)
Computational Design and Evaluation of New Materials for Energy and Environmental Applications.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
With a constant demand for efficient energy devices, significant efforts were invested into the development of proton exchange membrane (PEM) fuel cells. Yet, water management and hydration in these PEM fuel cells are a well-known limiting factors for proton transport. The first-principles density functional theory (DFT) study helped to develop two novel 2- D materials that can potentially alleviate the need for aqueous conditions to propagate proton conduction within fuel cells. Anhydrous proton conduction can be achieved when graphane is functionalized with hydroxyl and amine groups as graphamine and graphanol, respectively. Ab-initio molecular dynamics simulations indicated that the proton transport is facile with a relatively low reaction barrier due to the presence of a self-assembling network of hydrogen bonds established over the surface of these materials. Moreover, proton self-diffusivity increases with temperature and thermodynamic stability calculations indicate that these materials are appropriate for intermediate-temperature fuel cells.
Given the environmental concerns of tritiated water (HTO), this work is an attempt to understand the fundamental nature of differential hydrogen bonding offered by the hydrogen isotopes. When two phases (liquid and vapor) of water are in equilibrium, there can be slight difference in the relative abundance of water isotopes for each phase. The treatment of nuclei under classical mechanics is not appropriate for the study of lighter atoms like hydrogen and its isotopes. By employing path-integral-based molecular simulations one can account for quantum motion of the nuclei to determine isotopic fractionation ratios for water isotopologues in phase equilibrium and cocrystallization of water isotopologues with poly- oxacyclobutane. Due to the inherent computationally intensive nature of these calculations, a combination of reduced-cost and accelerated techniques such as high-order splitting and thermostating procedures were used to achieve convergence of quantum mechanical proper- ties.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Bagusetty, Abhishek | abb58@pitt.edu | abb58 | |
|
| ETD Committee: |
|
| Date: |
29 January 2020 |
| Date Type: |
Publication |
| Defense Date: |
18 November 2019 |
| Approval Date: |
29 January 2020 |
| Submission Date: |
15 November 2019 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
119 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Computational Modeling and Simulation |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
anhydrous, proton transport, path integral molecular dynamics, equilibrium isotope fractionation ratio |
| Date Deposited: |
29 Jan 2020 15:58 |
| Last Modified: |
29 Jan 2020 15:58 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/37798 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](/images/feed-icon-32x32.png){kind=icon}