Events

Separation processes are essential across all areas of modern manufacturing, ranging from critical element recovery to chemical and biochemical purification. For example, maximizing metal production while reducing water and chemical usage is central to next-generation mining. At the same time, in chemical and biochemical manufacturing, discriminating between structurally-similar molecules can be the major bottleneck to industrial feasibility.

Electrochemical processes offer a promising route toward molecularly selective separations. By controlling redox electron transfer at interfaces, my lab develops separation processes that can reversibly bind and release target species. First, we develop selective redox-electrosorption processes for the recovery and purification of critical metals, including platinum group metals (PGMs) and rare-earth elements (REEs). We elucidate the intermolecular interactions that drive selectivity, including the role of charge-transfer interactions and solvation. We then extend these concepts beyond electrosorption to establish an electrochemical liquid–liquid extraction process for continuous metal recovery.

Second, we demonstrate redox-mediated separations for challenging chemical purifications such as the recycling of homogeneous catalysts and even enantioselective separations. I also briefly present my group’s recent efforts in developing selective ion-exchange membranes for organic acid purification through redox-electrodialysis. We highlight the importance of integrating electrochemical engineering with multi-stage process design to enable efficient downstream processing in biomanufacturing.

Overall, redox-electrochemical platforms have shown generalizability across distinct separation modes and diverse application fields. We envision the continued growth and translation of electrochemical separations for industrially-relevant contexts.

Xiao Su is an Associate Professor in Chemical and Biomolecular Engineering at the University of Illinois, Urbana-Champaign. He obtained his Bachelor in Applied Sciences in Chemical Engineering from the University of Waterloo in 2011. He completed his PhD in Chemical Engineering from MIT in 2017, working under the supervision of Professor T. Alan Hatton from Chemical Engineering and Professor Timothy F. Jamison from Chemistry.

Since joining Illinois in 2019, his research seeks to develop new electrochemically-mediated separations through a combination of molecular design and electrochemical engineering. His team has tackled global challenges such as critical element recovery and materials recycling, sustainable mining, environmental remediation and water treatment, as well as chemical and biochemical manufacturing. A unique focus has been on understanding and leveraging redox-electron transfer at interfaces to achieve selective ion separations, and electrochemically combining reaction and separations for process intensification.

Xiao has been the recipient of the NSF CAREER Award (2019), the ACS Victor K. Lamer Award in Colloids & Surface Chemistry (2020), the ISE-Elsevier Prize for Green Electrochemistry (2021), the Merck Innovation Award (2021), the ACS Unilever Award in Colloids & Surface Chemistry (2023), the AIChE FRI/Kunesh Awards in Separations (2023), the ACS Satinder Ahuja Young Investigator Award in Separation Science (2024), and the DOE Early Career Award (2024). Xiao’s teaching has also been recognized by the List of Excellent Teachers (2019, 2022), and the School of Chemical Sciences Teaching Award (SCS) in 2023. He is also co-founder of Valor Metals Inc.