Energy Conversion Materials: Computational Design of Electrocatalysts Toward Sustainable Energy Applications
As the global-scale need for sustainable energy technologies emerges due to anthropogenic climate change, electrocatalysis plays a crucial role in facilitating many sustainable processes. Several heterogenous cathode materials can perform different electrochemical activities using water, oxygen, hydrogen, carbon dioxide to deliver renewable electricity and value-added chemicals. By using the density functional theory method, it is possible to explore the structural and electronic properties that govern a catalysts’ activity and selectivity. In this thesis, we start by exploring 48 reconstructed transition metal dichalcogenides edges (MX2, M = Mo, W; X = S, Se, Te) for carbon dioxide reduction reaction as an alternative to copper-based catalysts. Stabilities of all the reconstructed edges are calculated, followed by the binding energies of key reaction intermediates with a focus on the scaling relationship. Unlike Cu-based catalysts, we observe breaking of the linear scaling relationship for TMDCs, offering lower over-potentials and high selectivity. Fabrication of the reconstructed edges were explored using a controlled atomic fabrication method, delivering realizable stable structures with calculations performed to confirm the experimental findings. We shift to dual atom catalysts as alternatives to Pt-based catalysts for oxygen reduction. Starting with FeCu-N-C, we developed a computational workflow integrating configuration generation, microkinetic modeling and mechanistic pathways to provide design principles for high performing DACs. We further extended our method to explore a larger chemical space that includes 186 heteronuclear DACs (Fe-M2-N-C) where M2 are the later 3d transition metals Mn, Zn, Co, Ni, Fe, Cu, and 5d Pt, establishing a descriptor-based approach to identify DACs which outperform Pt (111). Finally, regenerative materials toward methane reform and electrolysis were investigated as alternatives to pure Ni catalysts. To improve DRM, westudied how the NiAu stoichiometry on Au-doped LaNiO3 affects the activation of methane at the surface. For SOEC applications, we examined the catalytic performance of Ni-doped LaFeO3 for electrolysis in the presence of sulfur contaminates.
Other Materials Science and Engineering, electrocatalysis, renewables, edge engineering, oxygen reduction reaction, carbon dioxide reduction reaction, dual atom catalysts, regenerative perovskites
City University of New York - Graduate Center
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The Graduate School and University Center of The City University of New York