CBC Colloquium Series: "Real-time electrocatalytic control of C-H and C-C bond transformation and fuel formation"

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Presenter:  

Dr. Marcel Schreir

Assistant Professor

Department of Chemical & Biological Engineering

University of Wisconsin - Madison

Biography

Prof. Schreier received his B.S. degree in Chemistry and Chemical Engineering from EPFL and his M.S. degree in Chemical and Bioengineering from ETH Zurich. During his studies, Schreier worked on Li-Ion Batteries at BASF and investigated Fischer-Tropsch refining mechanisms at the University of Alberta. His master’s research was performed in the laboratory of Sossina Haile at Caltech, where he designed materials for fuel cell electrodes. He subsequently joined the laboratory of Michael Grätzel at EPFL, where he developed electrocatalysts and devices for the sunlight-driven conversion of CO₂ to fuels. Following his passion for fundamental electrochemistry, he moved to MIT, where he worked with Yogesh Surendranath as an SNSF Postdoctoral Fellow. He subsequently joined the Department of Chemical and Biological Engineering at the University of Wisconsin-Madison as the Richard H. Soit Assistant Professor. He is also an affiliate faculty member of the Department of Chemistry. Together with his research group, Prof. Schreier works to understand how the structure of the electrochemical interface and the surface chemistry of catalytic materials influence the fundamental mechanisms which drive chemical transformations using electrical energy. While working at the University of Wisconsin, he has received the Beckman Young Investigator Award, a Packard Fellowship for Science and Engineering, and an NSF CAREER Award. He has been named a Scialog fellow, a Kavli Fellow (National Academy of Science) and has participated in several Frontiers of Engineering meetings of the National Academy of Engineering. Apart from electrochemistry, Prof. Schreier is passionate about modern art, energy systems, technologies of all kinds and policy.

Real-time electrocatalytic control of C-H and C-C bond transformation and fuel formation

Abstract

Producing fuels and chemicals using electricity has drawn considerable interest in recent decades. To date, research in electrocatalysis – the key tool which allows us to link electricity to chemical reactions – remains strongly focused on the transformation of small inorganic molecules such as CO₂, H₂O, N₂, and oxygenated biomass derivatives. Yet, comprehensive industrial electrification will likely require electrocatalytic methods that can promote the reactions that make up the core of the chemicals and fuels industry: n-alkane transformations.

In this talk, I will demonstrate that electricity-driven alkane transformations not only are feasible but that they also unlock new avenues of reactivity, offering solutions to long-standing challenges in catalytic alkane chemistry. Specifically, I will show how our group combined a fundamental understanding of interfacial electrocatalytic processes¹ with in-situ electrochemical mass spectrometry to gain independent, real-time control over the elementary steps of alkane transformations at room temperature. By modulating the potential applied to an electrocatalyst surface, we were able to independently control the adsorption of n-alkanes, initiate the transformation of adsorbates while they are bound to the surface, and selectively desorb desired products while keeping others anchored. These methods provide a powerful lever of control over catalytic surface chemistry, enabling us to demonstrate remarkable reactivity, including: (1) the room-temperature electrochemical fragmentation of ethane² and butane³ into shorter chain fragments, and (2) the room-temperature dehydrogenation of n‑alkanes to alkenes.⁴ Beyond these transformations, I will show how leveraging independent control over elementary steps allowed us to deconstruct the continuous oxidation of n-alkanes in fuel cells into its fundamental steps—identifying bottlenecks and providing new design principles for improved catalysts.⁵

In the final part of my talk, I will discuss how, at a fundamental level, applied voltages control the rate of electrocatalytic reactions. Electron transfer reactions are typically thought to pass through a vibrationally activated transition state, making them temperature dependent. However, we discovered that some electrocatalytic reaction classes, for example CO₂ reduction, show little to no temperature dependence, regardless of the catalyst or electrolyte. Building on previous reports by Halpern and Conway, I will discuss how our mechanistic interpretation of this phenomenon points to the translational, rather than vibrational, reorganization of electrolyte components to form an interfacial electron transfer transition state.⁶ I will also discuss how this insight highlights the importance of considering more than enthalpic activation barriers in designing electrocatalytic systems.

By extending electrocatalysis to alkane transformations and uncovering new mechanistic insights into reaction rate control, we aim to enable more precise atomic-level manipulation in electrocatalytic processes, paving the way for a more selective, efficient, and electrified chemical industry of the future.

References

1. Schreier, M., Kenis, P., Che, F., and Hall, A.S. ACS Energy Lett.  8, 9, 3935–3940 (2023).
2. Bakshi, H.B.‡ , Lucky, C. ‡, Chen H-S., Schreier, M. J. Am. Chem. Soc. 145, 13742–13749 (2023).
3. Lucky, C., Jiang, S., Shih, C.-R., Zavala, V., Schreier, M. Nature Catalysis 145, 1021–1031 (2024).
4. accepted
5. accepted
6. Noh, S., Yoon Jin Cho, Zhang, G., Schreier, M. J. Am. Chem. Soc. 145, 27657–27663 (2023). 

Hosted by: Dr. Yan