Saravanan, Karthikeyan
(2019)
Computational High Throughput Searches for Efficient Catalysts.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
Several screening studies identifying new catalysts for different reactions have been reported over the past decade. Almost all of them employ Kohn-Sham density functional theory (KS-DFT) and thermodynamic descriptors to screen for new catalysts. Though usually considered reliable for descriptor-based analyses, KS-DFT calculations are computationally expensive and intractable for use when screening across the full chemical space of all possible alloy materials. In order to accelerate screening of catalysts, we employ a perturbation theory model, ”Computational Alchemy” to approximate KS-DFT energies at a fraction of the computational cost. In this thesis, we discuss about how computational alchemy and machine learning can be used to reliably screen for efficient catalysts for a wide range of electrochemical processes based on thermodynamic activity descriptors.
As a first step, we assess the promise of computational alchemy in predicting binding energies thousands of times faster than DFT. We identify distinct cases where alchemy performs significantly worse, indicating areas where modeling improvements are needed. We find that alchemical estimates yield binding energies within 0.1 eV of DFT values for a wide range of adsorbates. Largest errors (≈ 0.4 eV) were observed when Alchemy predicted BEs of the adsorbates on alloys that were obtained by changing large number of atoms and to a large change in nuclear charge. Using a Machine learning approach, the errors between Alchemy and DFT were corrected. Our results suggest that computational alchemy with machine learning is a very promising tool that warrants further consideration for high-throughput screening of heterogeneous catalysts.
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Details
Item Type: |
University of Pittsburgh ETD
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Status: |
Unpublished |
Creators/Authors: |
Creators | Email | Pitt Username | ORCID |
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Saravanan, Karthikeyan | kas389@pitt.edu | kas389 | |
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ETD Committee: |
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Date: |
24 January 2019 |
Date Type: |
Publication |
Defense Date: |
19 November 2018 |
Approval Date: |
24 January 2019 |
Submission Date: |
30 October 2018 |
Access Restriction: |
2 year -- Restrict access to University of Pittsburgh for a period of 2 years. |
Number of Pages: |
123 |
Institution: |
University of Pittsburgh |
Schools and Programs: |
Swanson School of Engineering > Chemical Engineering |
Degree: |
PhD - Doctor of Philosophy |
Thesis Type: |
Doctoral Dissertation |
Refereed: |
Yes |
Uncontrolled Keywords: |
Computational Chemistry, DFT, Machine Learning, Alchemy |
Date Deposited: |
24 Jan 2019 15:46 |
Last Modified: |
24 Jan 2021 06:15 |
URI: |
http://d-scholarship.pitt.edu/id/eprint/35610 |
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Computational High Throughput Searches for Efficient Catalysts. (deposited 24 Jan 2019 15:46)
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