Heterogeneous metal catalyst for electrochemical applications

Abstract

Electrochemical energy conversion driven by renewable electricity offers a promising strategy to reduce dependence on fossil fuels. Among various systems, heterogeneous molecular catalysts (HMCs) have attracted attention due to their well-defined active sites and tunable structures. By immobilizing transition metal complexes onto solid supports, HMCs combine molecular-level precision with the advantages of heterogeneous catalysis. However, their performance strongly depends on interactions between metal centers and supports, which regulate electronic structure and reaction pathways.

This thesis systematically investigates the synergistic roles of carbon support geometry, surface chemistry, and metal site configuration in HMCs. Chapter III shows that the curvature of carbon nanotubes (CNTs) modulates electron distribution and adsorption behavior, significantly enhancing H₂O₂ selectivity in the two-electron oxygen reduction reaction (2e⁻ ORR). Chapter IV demonstrates that the CO₂-to-methanol performance of CoPc supported on CNTs is strongly dependent on surface oxygen functional groups, and this effect can be extended to other reactions.

Building on these findings, HMCs with tunable single-atom and dual-atom configurations are developed to regulate CO₂RR product selectivity. Overall, this work reveals the synergistic regulation of electrocatalysis across support geometry, surface chemistry, and metal site structure, providing design principles for advanced heterogeneous catalysts.