(7fx) Molecular Design of Redox-Active Electrochemical Interfaces: Selective Separations and Beyond

Molecular level design is crucial for the development of new and more efficient electrochemical processes for a range of industrial and environmental applications. In particular, selective separations remain among the most important steps in the chemical and biochemical industries, and are crucial for water purification and environmental remediation. Thermal and pressure-based separations often incur high energetic costs, while fixed-bed adsorption requires environmentally harmful solvents and regenerants. This is a particularly challenging task for the recovery of value-added products, and the mitigation of micropollutants of emerging concern. Although there has been great interest in electrochemical systems for energy storage and electrocatalysis, their use in separation science has been severely limited by the lack of molecular selectivity.

Redox-active species offer an attractive materials platform, especially organometallic compounds (e.g. metallopolymers and associated metal-organic complexes), due to the ability to control electronic and binding properties. My research interests focus on tuning the electrode interfaces at a molecular scale, to overcome the inherent limitations of current technologies. We engineer specific Faradaic-driven interactions to provide selectivity, and study electrochemical processes across several scales:

(i) We probe the intermolecular binding mechanisms through a combination of electronic structure (DFT) calculations and spectroscopy, and tune these interactions through synthetic functionalization of our electrodes. We enable the selective sorption and release of anions, cations, and even proteins, based solely on electrochemical control, in the presence of excess competing species.

(ii) At the nanoscale, we explore the physico-chemical behavior of our redox-active polymer films through in-situ measurements, especially during selective binding, and point to emerging directions beyond separations such as new materials development.

(iii) From an electrochemical cell perspective, we propose asymmetric Faradaic systems as a next generation configuration with higher charge efficiency and separation factors. We focus on counter-electrode design, in which the redox processes at the cathode and anode operate in tandem, lowering operating voltages, preventing parasitic side-reactions and ultimately enhancing ion-selective performance.

Fundamentally, the concepts explored shed insight on interfacial interactions of organic and inorganic ions with electrode surfaces; from a practical perspective, we propose electrochemical-swing processes as a key direction for sustainable separations. In the long-term, we expect integrated electrochemical systems to contribute greatly towards process intensification in the chemical industry.

Teaching Interests:

My teaching interests are in the areas of transport processes (in particular heat and mass transfer), separations science, thermodynamics/physical chemistry, and reaction engineering/kinetics. I am interested in focusing initially on the core classes in the classical chemical engineering curriculum, at both an undergraduate and graduate level. In parallel, I plan to develop an advanced class on electrochemical methods for chemical engineers. From a broader educational perspective, I would like to bring an aspect of scientific writing and presentation skills into more senior courses, to strengthen training on these aspects, and foster a degree of scientific inquiry for the students within a class environment.