(4gr) Computationally Accelerated Waste Valorization Via Materials Discovery and Design

My research group aims to accelerate materials discovery for waste valorization by combining advanced molecular simulations, machine learning, and high-throughput screening. Both climate change and sustainable energy each pose a significant challenge to humanity; however, these challenges are not mutually exclusive. My group will develop materials for carbon capture and storage (CCS) to address climate change, and waste-to-energy conversion as a source of energy production. Materials discovery will have a significant role in addressing these global concerns, with new separation and catalytic materials advancing our current capabilities being an essential requirement. These new materials provide unique opportunities for harnessing waste, such as waste natural gas (i.e., CH₄) from shale gas fields and municipal waste or CO₂ from greenhouse gas emissions, into higher-value chemical commodities. I will leverage my expertise in molecular simulations from my graduate and postdoctoral projects to accelerate materials discovery for waste valorization applications. Specifically, my research enterprise will:

(I) Rationally design CO₂ sorption and dual-function materials for carbon capture and conversion

(II) Develop computationally guided insights into the influence of ligands on catalysis for improved-waste-to-energy conversion, and

(III) Advance the fundamental understanding of actinide heterogeneous catalysts for small molecule activation.

Additionally, the group will (IV) develop computational tools for investigating the dynamic structural and composition changes due to varying environmental conditions within catalytic materials. Each aim of my research enterprise accelerates material discovery for waste valorization.

Previous Research Experience:

At Clemson University, my research utilized advanced molecular simulations to investigate new catalytic and adsorption materials for climate change and energy production. Under the mentorship of Dr. Rachel B. Getman, my work contributed to our understanding of the catalytic and adsorption phenomena on a molecular level. Projects included identifying the catalyst structure at different operating conditions and the proton mobility in liquid-based, eutectic solvents for the direct air capture of CO₂. For catalytic materials, operating conditions (i.e., temperature and pressure) are known to alter the catalyst composition and structure. In metal-organic frameworks (MOFs), the chemical intuition into how these operating conditions impact the catalyst composition and structure (and therefore function) is lacking. My main catalytic project investigated the ligand environment of a Ni-oxo (Ni₄O_xH_y clusters) catalyst supported on the NU-1000 MOF under catalytic hydrogenation conditions. Using ab initio thermodynamic analysis combined with pair distribution function (PDF) analysis, the project demonstrated the structural evolution of the Ni-oxo cluster by directly comparing the model catalyst structure PDFs with the experimental PDFs. Furthermore, I utilized ab initio thermodynamic analysis to develop a Ni/UiO-66 catalyst model that rationalizes an additional, spectator ethylene molecule in high-pressure ethylene oligomerization reaction mechanisms. Additionally, new materials are needed for the direct air capture (DAC) of CO₂ to address climate change. Both deep eutectic solvents (DESs), a subset of ionic liquids (ILs), are promising new liquid sorbent materials for DAC. I used molecular simulations to elucidate structure-function relationships between the DES/IL and CO₂ chemisorption, revealing the CO₂ sorption mechanism and the structural differences in the hydrogen bonding network that led to differences in performance between the DES and IL. My findings had a direct impact on our understanding of the catalytic and adsorption phenomena on a molecular level. Using quantum chemical calculations, I investigated the structures and functions of new materials that ultimately provided key insights to my experimental collaborators.

My postdoctoral research at Savannah River National Laboratory (SRNL) expands on a side project from the last year of my PhD, which developed a model to understand the indirect second sphere coordination effects within metal-organic framework (MOF) heterogeneous catalysts. Traditional second sphere coordination effects, such as non-covalent and steric interactions, are well-established within the literature. However, recent experiments in MIL-100(Fe), a MOF consisting of triiron oxo-centered clusters [Fe(II)Fe(III)Fe(III)(μ₃-O)]⁶⁺, demonstrates unique catalytic properties depending on the hydration of the MIL-100(Fe) node. The oxo formation reaction (N₂O + *Fe(II) à N₂ (g) + *Fe(IV)=O) is sensitive to the ligand environment at the inactive Fe(III) sites. An increase in the node hydration (i.e., H₂O ligands at the Fe(III) sites) results in an increased apparent active barrier. Using quantum chemical simulations, I demonstrated that the communication between the H₂O ligands and the Fe(II) active site occurs through the central Fe(III)-O-Fe(II) backbone. These findings highlight the potential for tuning catalysis through indirect second sphere effects. As a Dwight D. Eisenhower Postdoctoral Research Fellow, I’m continuing to investigate these indirect second sphere coordination effects as the recipient of a grant from DOE Savannah River. My research is focused on providing further insights into the communication between the active site (Fe(II)) and the secondary metal sites (i.e., M(III), where M = Fe(III), Al(III), V(III), etc.). By combining quantum chemical calculations, high-throughput screening, and machine learning, my work is exploring the sensitivity of these indirect second sphere coordination effects and the chemical descriptors that govern these effects in MOFs and other single-site heterogeneous catalysts.

Mentoring and Teaching Interests

My prior teaching and mentoring experiences demonstrate my commitment to fostering learning and curiosity while creating an inclusive environment. I developed my teaching pedagogy while taking courses and interacting with faculty in Clemson University’s Engineering Science and Education Department, which I had the opportunity to pursue because of my Graduate Assistant in Areas of National Need (GAANN) Fellowship. As a GAANN Fellow, I developed lectures (three total throughout the semester), quizzes (ten total), and led the discussion sections for the sophomore-level materials and energy balance course. Through my experiences, I developed a pedagogy that believes learners should be active in the construction of meaning and knowledge (constructive) and should make connections between concepts and real-world experiences such that their knowledge can be applied to more complex problems (integrative). By rooting a student’s understanding in fundamental and relatable examples, they can develop the necessary skills to be challenged to think more critically about complex problems. During the final year of my PhD (Spring 2023), I gained another valuable experience when I was asked by the department chair to teach the sophomore undergraduate heat transfer course for five weeks. The experience was enlightening and rewarding as I developed thirteen lectures two group work projects, and a final exam question. Being the primary instructor for the heat transfer course enabled me to further define, refine, and grow my teaching pedagogy through actual practice. I also gained an understanding of the responsibilities of being a professor and balancing research, teaching, and service (i.e., Graduate Student Government Treasurer). I feel prepared to handle the research, teaching, and service requirements expected of a tenure-track research faculty. Additionally, I am willing and able to teach all undergraduate courses with a preference for the graduate transport class. I would also like to teach an elective class, such as Mathematics and Programming for Chemical Engineers, that combines chemical engineering concepts, mathematics and programming.

The same pedagogy and skills I’ve developed within the classroom I’ve applied to research mentorship opportunities. Throughout my PhD, I had opportunities to mentor undergraduate (four) and high school (one) students. Each experience enabled me to develop my mentorship strategies, such as how to tailor my interactions to promote the intellectual growth and independence of each mentee. These experiences enabled me to define my research mentorship goals: (1) developing research and communication (oral and written) skills, (2) expanding their professional network, (3) assisting in the pursuit of their career goals, and (4) encouraging personal growth and well-being. My last REU mentee, a rising senior from a small school in Texas, solidified my mentorship goals. I served as the sole mentor in introducing them to scientific research, while teaching them the basics of quantum chemical simulations and heterogeneous catalysis. The student thrived with my ‘challenge’ problems and produced meaningful results by the end of the ten-week program; they are starting a PhD in the Department of Chemistry at Washington State University (Fall 2024). My desire to pursue a tenure-track faculty position is solidified by my teaching and mentorship experiences. My goal is to improve the world through research, education, and mentoring by giving my students the support they need to achieve their goals, the platform to be themselves, and the opportunity to positively impact those around them.