Catalytic interfaces in and out of equilibrium

Please join Yale Chemistry for a Silliman Seminar in theory/ physical chemistry with Prof. Anastassia Alexandrova, a Charles W. Clifford Jr. Professor in Chemistry and Biochemistry, and Professor of Materials Science and Engineering, from University of California Los Angeles.

Abstract: Catalytic interfaces in reaction conditions undergo significant morphological changes, support high coverage with reagents and intermediates, and often undergo relentless structural and stoichiometric dynamics coupled to the reaction itself. Not surprisingly, successful catalyst formulations are usually found by chance. The talk will show grand canonical modeling of catalytic interfaces, maximally approaching reaction conditions. Simulations, and joint experimental studies, reveal interfacial fluxionality and ongoing dynamics. We reveal that statistical ensembles of many catalyst states (geometries and stoichiometries) are populated (1), and jointly control all catalyst properties, from activity and selectivity (2,3), to deactivation propensity (4,5), and operando spectral signatures (6). Swarms of reaction mechanisms are simultaneously in operation. Non-trivial kinetic effects represent a particular new challenge for modeling. Less stable, transient catalyst states can be driving all the catalysis (3). Furthermore, catalysis appears to reach phase boundaries in the steady state and exploit the associated instability to drive reactivity, often slipping into a non-equilibrium regime (7,8). Example systems illustrating this paradigm include supported cluster catalysis for dehydrogenation, and electrocatalysts for hydrogen evolution and CO₂ reduction reactions.

The principal effort of the Alexandrova research program is the design of new functional materials. One focus is on heterogeneous (electro)catalysis, especially the dynamics of interfaces in operando conditions. Here, a significant emphasis is on environmentally important problems such reactive capture of CO₂. Another important direction is the design of qubits with increasing chemical complexity, and their assemblies, as well as quantum sensors. The group studies fundamental effects of electric fields on chemical reactivity, particularly in enzymes, and designs artificial metalloenzymes. Efforts are guided by insights into electronic structure and chemical bonding and driven by novel algorithms developed by the group. We use a large range of methods (DFT, ab initio, QM/MM, MD, MC, novel reaction path samplings, global optimizations, etc.), and often make them multi-scale, combining several different approaches, and powering them by tricks from artificial intelligence and machine learning. Both applied and method-development efforts are prominent in the group, and they are a warm home for students of many different backgrounds, from chemistry and biochemistry, to physics, material science and engineering, computer science, and applied mathematics. For more information on Prof. Alexandrova’s research: Alexandrova Lab

Faculty Host: Prof. Mark Johnson

Sponsored by the Mrs. Hepsa Ely Silliman Memorial Fund

1. Zhang, Z.; Zandkarimi, B.; Alexandrova, A. N.  Acc. Chem. Res. 2020, 53, 447-458.
2. Zhang, Z.; Masubuchi, T.; Sautet, P.; Anderson, S. L.; Alexandrova, A. N.  Angew. Chem. Int. Ed. 2023, 62, e2-2218210
3. Li, G.; Poths, P.; Morgan, H. W. T.; Masubuchi, T.; Alexandrova, A. N.; Anderson, S. L.  ACS Catal. 2022, 13, 1533-1544.
4. Poths, P.; Alexandrova, A. N.  J. Phys. Chem. Lett. 2022, 13, 4321-4334.
5. Zandkarimi, B.; Sautet, P.; Alexandrova, A. N. J Phys Chem C 2020, 124, 10057-10066
6. Poths, P.; Hong, Z.; Li, G.; Anderson, S. L.; Alexandrova, A. N.  J. Phys. Chem. Lett. 2022, 13, 11044-11050.
7. Poths, P.; Vargas, S.; Sautet, P.; Alexandrova, A. N.  ACS Catal. 2024, 14, 5403-5415.
8. Zhang, Z.; Gee, W.; Sautet, P; Alexandrova, A. N.  J. Am. Chem. Soc. 2024, 146, 16119-16127