432349 Transition Metal-Oxides for Sustainable Energy Conversion and Storage: The Computational Catalysis Perspective

Sunday, November 8, 2015
Exhibit Hall 1 (Salt Palace Convention Center)
Michal Bajdich, Chemical Engineering, Stanford University, Stanford, CA

My primary research focus will be on the fundamental understanding of the catalysis and surface phenomena in transition metal-oxides (TMO) and their application towards sustainable energy conversion and storage. While TMOs are frequently used as photosensitive semiconductors (TiO2), in recent years, they have become a central component of electro-chemical processes. They are commercially used as the cathode material in batteries1 and have shown promising potential as heterogeneous catalysts2 and electrode materials for pseudocapacitators3 and solid-oxide fuel cells.4Since electrochemical processes occur at interfaces, it is crucial to develop a fundamental understanding of TMO surfaces.

            A good illustration of this topic in my latest research on ultra-thin layers of TMOs, which can be stabilized when interfaced with precious metal supports such as Au(111) or Pt(111). Additionally, the gold supported Co/Ni/Mn-based catalysts have also been experimentally proven to exhibit higher oxygen evolution reaction (OER) activities than other metal supported oxide catalysts.5–7However, the explanation of synergistic effect of contact with gold support remains elusive and detailed theoretical models of the catalysis at the active site are need to fully explain this phenomenon.

            TMOs are also known to exist in a wide variety of surface structures, which exhibit distinct physical properties: surface relaxation and structural defects, localization of electronic states, modifications from the electrolyte environment and variations in voltage bias, and site-specific interactions.  All such phenomena have only been weakly explored and are therefore poorly understood. Conventional ab-initio methods are generally not accurate or efficient enough to be predictive of the unique physical properties of TMOs surfaces.  Therefore, higher accuracy theoretical methods with acceptable efficiency are urgently needed, in order for theory-guided optimization of TMO surfaces.

            From the above perspective, the main objectives of my research will be a) to discover new materials with enhanced surface properties for applications in energy conversion and storage accelerated by b) classification of important surface structures of TMOs and mapping their energetics with versatile descriptors and further improved by c) development of more accurate but scalable state-of-the-art ab-initiosimulation methods applicable to TMOs.

(1)       Tarascon, J.-M.; Armand, M. Nature 2001, 414(6861), 359–367.

(2)       Luo, J.; Im, J.-H.; Mayer, M. T.; Schreier, M.; Nazeeruddin, M. K.; Park, N.-G.; Tilley, S. D.; Fan, H. J.; Grätzel, M. Science 2014, 345(6204), 1593–1596.

(3)       Augustyn, V.; Simon, P.; Dunn, B. Energy Environ. Sci. 2014, 7(5), 1597–1614.

(4)       Fergus, J.; Hui, R.; Li, X.; Wilkinson, D. P.; Zhang, J. Solid Oxide Fuel Cells: Materials Properties and Performance; CRC Press, 2008.

(5)       Yeo, B. S.; Bell, A. T. J Am Chem Soc 2011, 133(14), 5587–5593.

(6)       Yeo, B. S.; Bell, A. T. J. Phys. Chem. C 2012, 116(15), 8394–8400.

(7)       Kuo, C.-H.; Li, W.; Pahalagedara, L.; El-Sawy, A. M.; Kriz, D.; Genz, N.; Guild, C.; Ressler, T.; Suib, S. L.; He, J. Angew. Chem. 2014, n/a – n/a.

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