Graduate Program

Chemistry

Degree Name

Master of Science (MS)

Semester of Degree Completion

Summer 2023

Thesis Director

Steven Pellizzeri

Thesis Committee Member

Edward M. Treadwell

Thesis Committee Member

Hongshan He

Thesis Committee Member

Radu F. Semeniuc

Thesis Committee Member

Zhiqing Yan

Abstract

Finding a good catalyst for C-H bond breaking is important due to the rise of natural gas and crude oil emissions. From 2000-2006, CH4 emission concentrations stabilized, but in 2007, it sharply started increasing again. For example, atmospheric CH4 levels were 1886.37 ppb in July 2021 but this rose to 1904.52 ppb in just one year. Precious metal catalysts, such as Ir systems, have been used for C-H bond breaking, but are not sustainability ideal as they are costly to produce and have a significant carbon footprint. Because of this, less expensive 3d metal catalysts have risen in investigative popularity. The Fe-centered White Chen catalyst was able to oxidize inactive sp3 bonds in C-H. From this discovery, many other metal systems have been developed, specifically the modified metalloporphyrin catalyst system used in this paper.

In this study, multiple different pathways were computationally investigated using a modified first row metalloporphyrin graphene system to determine the best pathway and system for CH4 adsorption and activation. Both the use and absence of the Hubbard U parameter was explored to decide the parameters for experimental use. Nudged elastic band (NEB) simulations were calculated to determine the energy barriers for each pathway, which was crucial in establishing the best pathway. This data was then used to calculate and plot the rate of adsorption and the rate of activation. From this, it was determined that the employment of the Hubbard parameter improved the activation energies, while, making the CH4 adsorption to be slightly less favorable.

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Available for download on Saturday, July 19, 2025

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