(6ge) Sustainable Materials for Separations and Catalysis

Research Interests: A long-standing challenge in materials science is the development of functional materials with the ability to separate and convert chemicals in the same material system. Traditionally, these processes are separated into several multi-step operations and an improvement in materials resulting in a reduction of the necessary number of steps would provide considerable benefit beyond that offered by the production of value added products. Inorganic/organic hybrid materials such as MOFs have unique properties including flexibility, hierarchical structure, and tunable chemistries that make them interesting candidates for health, separations, and catalysis applications. In such systems, the MOF architecture strongly affects material functionality. However, synthesizing these materials in functional forms is challenging due to their inherent instability. My research aims to directly address this challenge by developing new approaches to synthesize MOF hybrid materials with precise control over stability, structure, and functionality to elucidate the relationship between molecular-scale properties and macroscopic material performance, with the overarching goal of enabling better understanding of structure and properties of MOF hybrid materials.

Successful Proposals: Oak Ridge National Laboratory, CNMS (2016); Brookhaven National Laboratory, CFN (2018)

Postdoctoral Projects: Activity and Stability Design Principles of Non-Noble Metal Catalysts to Promote Oxygen Reduction and Oxygen Evolution Reaction Kinetics and Active and Sinter Resistant Transition Metal Nitride/Carbide Nanomaterials for Methane Dry Reforming, Department of Chemical Engineering, Massachusetts Institute of Technology (Advisor: Professor Yuriy Román-Leshkov).

Ph.D. Dissertation: Acid and Base Gas Exposure and Solvent Effects on Metal-Organic Framework (MOF) Structural and Gas Adsorption Properties, Department of Chemical & Biomolecular Engineering, Georgia Institute of Technology (Advisor: Professor Krista S. Walton)

Research Experience: My research focuses on the development of new classes of inorganic and inorganic/organic hybrid materials by studying and engineering the effects of synthesis and acid and base gases on material structure and properties. In my Ph.D. research, I studied the adsorption of acid and base gases on metal-organic frameworks. Specifically, I studied the effects of acid gas degradation on metal-organic frameworks to develop an understanding of adsorbed species-property relationships and determine the acidic species involved in the degradation mechanism through a combined experimental and computational approach. Using this approach, I synthesized a variety of metal-organic frameworks and characterized their material properties during acid gas adsorption through the use of a variety of characterization techniques including in situ diffuse reflectance infrared Fourier transform spectroscopy.[2-4] These studies have increased the understanding of the interactions between acidic and basic species and MOF materials.

In my postdoctoral research, I developed synthetic methods to produce unsupported transition metal carbide nanoparticles and monolayer phase-pure carbide nanosheets for catalytic applications. Using these materials I studied the effects of oxidation on monolayer carbides and the effect of morphology on the activity and stability of carbide materials for dry reforming of methane using a variety of characterization techniques, including powder X-ray diffraction, transmission electron microscopy, scanning transmission electron microscopy, and Raman spectroscopy. This work holds the potential to advance the fundamental understanding of carbide materials, impacting the design of novel functional catalysts for a variety of applications in thermal and electrocatalysis.

Future Research Directions: As an independent investigator, I will study materials for reactive adsorption and separation. Initial investigations in the Mounfield Group will consist of three aims (1) synthesis and investigation of inorganic/organic hybrid materials for adsorption of specific chemicals, (2) synthesis and investigation of catalysts for the conversion of these chemicals to value added products, and (3) preparation of reactive adsorbents for separation and conversion for industrial application. This work will require a multidisciplinary approach, combining my Ph.D. work in synthesis and separations with my postdoctoral work in synthesis and catalysis.

Teaching Experience: During my Ph.D., I served two semesters as a teaching assistant (TA) for Chemical Process Principles (ChBE 2100) and one semester for Graduate Mass Transport (ChBE 6260). In both semesters of serving for the introductory undergraduate course, I was selected to lecture several classes, which afforded me the opportunity to lecture weekly and prepare problem sets. Furthermore, I taught several lectures for the graduate course as well. In addition to my teaching experiences in my Ph.D., while studying at University of Florida, I led the development of an undergraduate laboratory course utilizing fuel cells to illustrate principles of general chemistry. During my graduate and postdoctoral career, I have had the privilege to mentor several outstanding undergraduate and graduate students, who continued their careers at places such as, ExxonMobil, Dow, and Tesla and graduate research in Chemical Engineering at UPenn.

Teaching Interests: My teaching interests include the central courses in Chemical Engineering – Mass Transport, Transport Phenomena, and Kinetics and Reactor Design. In addition, I am also interested in teaching Thermodynamics, Math Modeling and courses on materials characterization techniques.

Selected Publications:

1. Mounfield, WP; Garg, A; Shao-Horn, Y; Román-Leshkov, Y. Electrochemical Oxygen Reduction for the Production of Hydrogen Peroxide. Chem. 4, 2017, 18-19.
2. Mounfield, WP; Han, C; Pang, SH; Tumuluri, U; Jiao, Y; Bhattacharyya, S; Dutzer, MR; Nair, S; Wu, Z; Lively, RP; Sholl, DS; Walton, KS. Synergistic Effects of Water and SO₂ on Degradation of MIL-125 in the Presence of Acid Gases. Phys. Chem. C, 120, 2016, 27230-27240.
3. Mounfield, WP; Taborga Claure, M; Jones, CW; Walton, KS. Synergistic Effect of Mixed Oxide on the Adsorption of Ammonia with Metal-Organic Frameworks. Eng. Chem. Research. 55, 2016, 6492-6500. ACS Editor’s Choice Paper
4. Mounfield, WP; Tumuluri, U; Jiao, Y; Li, M; Dai, S; Wu, Z; Walton, KS. Role of Defects and Metal Coordination on Adsorption of Acid Gases in MOFs and Metal Oxides: An In Situ IR Spectroscopic Study. Meso. Mater. 227, 2016, 65-75.
5. Mounfield, WP and Walton, KS. Effect of Synthesis Solvent on Breathing Behavior of MIL-53(Al). Colloid Interface Sci. 447, 2015, 33-39.