(334p) Device-Level Engineering of Electrocatalytic Reactors Under Practical Operating Conditions to Enable Sustainable Small-Molecule Transformations

I am a Ph.D. student working with Prof. Karthish Manthiram in the Chemical Engineering department at MIT. I will be completing my Ph.D. in 2021. I am passionate about pushing the frontiers of sustainable chemistry swiftly and practically, so that we may have the best chance of maintaining a human-habitable planet in the coming decades; it is my hope that through my career I may contribute to this grand endeavor in some way. My doctoral research has focused on tying in chemical engineering fundamentals to practical problems in electrochemical synthesis. In the next steps of my career, I would like to move further in the direction of developing electrosynthetic reactor systems on a device level.

Research Interests

Electrochemistry is one promising route toward renewable energy storage and sustainable chemical synthesis. For example, using renewably-sourced electricity to drive water splitting is a lower-greenhouse-gas-emission alternative to steam methane reforming for the production of hydrogen; in addition, greenhouse gases such as CO₂ can themselves be transformed back into fuels and useful products using electrochemical potential. However, such processes require both fundamental study and device development in order to be economically feasible, whether or not they are accompanied by policy solutions such as carbon pricing. In modern electrocatalysis, reactions span a wide range of developmental stages. Processes such as chlorine evolution and aluminum smelting have long been staples of industry, and water splitting for the generation of hydrogen gas is nearing large-scale implementation; whereas the electrochemical reduction of carbon dioxide, while widely researched, is only beginning to be studied at high rates and moderate scales. Less developed still are reactions such as electrochemical nitrogen reduction or the direct oxidation of small organic molecules for synthetic purposes. Additionally, with some exceptions, when these reactions are studied, they are usually done so independently from their counter reactions – the reactions at the counter electrode required in order to complete the circuit.

With these points in mind, I am interested in two major approaches toward electrochemical research: (1) leveraging the state-of-the-art catalysts for small molecule transformations to study the impacts of device design upon the kinetics and transport of reactions, including the hydrogen evolution reaction, CO₂ reduction reactions, N₂ reduction reaction, and organic oxidative functionalization reactions using water as the O-atom source, under industrially-relevant conditions – for example, using realistic feedstocks – and in this way, connecting device development with fundamental understanding. (2) Examining the impacts of tuning the counter reaction on both the efficacy and the technoeconomics of the working reaction. For example: could we leverage clever flow fields to separate products made at the cathode and anode without the need for a physical separator? How do we understand the tradeoffs between the energy required to pump electrolyte, or to overcome ion diffusion resistance in physical separators, versus to perform downstream separations? Might it be possible to alter the economic prospects of reactions such as hydrogen evolution or CO₂ reduction by altering the counter reaction to perform a more lucrative partial oxidation reaction as opposed to oxygen evolution? If so, are there oxidative substrates that could be employed in such a way that electrolyte conditions enable synergistic interactions between oxidative and reductive substrates?

Ph.D. Research

Two major projects I have pursued during my doctoral research include: (1) uncovering the role of mass transport in protecting the CO₂ reduction reaction from parasitic side reactions with gas-phase contaminants, and (2) understanding solvent non-idealities in blended aqueous—nonaqueous electrolytes during electrochemical oxidative O-atom transfer reactions involving water. During this work I have extensively employed skills in electrochemical kinetic analysis, bulk electrolysis, cyclic and square-wave voltammetry, gas flow setup, gas chromatography, headspace sampling for solution thermodynamic measurements, and quantitative nuclear magnetic resonance (NMR) spectroscopy. I have additional experience in solid-state and colloidal approaches to metal oxide and nanoparticle synthesis; X-ray absorption spectroscopy (XAS); X-ray photoelectron spectroscopy (XPS); powder X-ray diffraction (XRD); UV-visible spectrophotometry; electron microscopy (SEM/TEM); elemental analysis via inductively coupled plasma (ICP); hydraulic pressing; organic synthesis; practical glassblowing; chemisorption analysis; and ultra-high vacuum (UHV) setups.

Selected Publications

Williams, K.; Corbin, N.; Zeng, J.; Lazouski, N.; Yang, D. T.; Manthiram, K. Protecting Effect of Mass Transport during Electrochemical Reduction of Oxygenated Carbon Dioxide Feedstocks. Sustain. Energy Fuels 2019, 3 (5), 1225–1232.

Lazouski, N.; Chung, M.; Williams, K; Gala, M. L.; Manthiram, K. Non-aqueous gas diffusion electrodes for rapid ammonia synthesis from nitrogen and water-splitting-derived hydrogen. Nature Catalysis 2020, 3 (5), 463-469.

Zeng, J.; Corbin, N.; Williams, K.; Manthiram, K. Kinetic Analysis on the Role of Bicarbonate in Carbon Dioxide Electroreduction at Immobilized Cobalt Phthalocyanine. ACS Catalysis 2020, 10 (7), 4326-4336.

Lazouski, N.; Schiffer, Z. J.; Williams, K.; Manthiram, K. Understanding continuous lithium-mediated electrochemical nitrogen reduction. Joule 2019, 3 (4), 1127-1139.

Yang, D. T.; Zhu, M.; Schiffer, Z. J.; Williams, K.; Song, X.; Liu, X.; Manthiram, K. Direct Electrochemical Carboxylation of Benzylic C-N Bonds with Carbon Dioxide. ACS Catalysis 2019, 9 (5), 4699-4705.

Corbin, N.; Zeng, J.; Williams, K.; Manthiram, K. Heterogeneous molecular catalysts for electrocatalytic CO₂ reduction. Nano Research 2019, 1-33.