Structural Design and Synthesis of Bio-Organometallic Complexes for Use in Electrochemical H2 Evolution and CO2 Reduction

Abstract

Developments in sustainable energy systems have been investigated as solutions to the climate crisis caused by greenhouse gas emissions. Various approaches, such as CO2 capture and utilization (CCU), or the use of H2 as an energy carrier for carbon-free systems, have been explored to address the climate crisis. To this end, many electrocatalysts have been developed for efficient conversion of energy into chemical bonds. Specifically, homogeneous electrocatalysts have provided insightful strategies for efficient electrocatalysis through well-defined structure-activity relationships. Among the developed electrocatalysts, bio-organometallic complexes, which mimic the structural aspects of metalloenzymes, have shown remarkable potential in electrocatalysis due to their efficient utilization of earth-abundant metal ions. The synthesized bio-organometallic complexes were inspired by the metabolism of metalloenzymes, which efficiently convert H2 and CO2 for their functions. The catalytic strategies of these complexes focus on stabilizing reaction intermediates through hydrogen bonding, electrostatic interaction, and structural dynamics, ultimately stabilizing reduced metal center. In this dissertation, we modified organometallic catalysts into electrocatalysts by incorporating structural aspects of metalloenzymes into their design. Specifically, ligating auxiliary ligands into organometallic complexes shifted their reactivity towards desired electrochemical reactions using facile synthetic routes. We also evaluated the catalytic performance of these metal complexes and investigated their mechanism to provide insightful structure-activity relationships.