Proceedings of MATSUS Fall 2024 Conference (MATSUSFall24)
Publication date: 28th August 2024
Electrochemical reduction of CO2 to valuable chemical fuels provides a promising pathway for reducing the continuously growing global carbon footprint. One of the critical components of an efficient electrochemical CO2 reduction system is the catalyst which accelerates the reaction’s kinetics.
Metal-Organic Frameworks (MOFs) are a class of crystalline coordination polymers with high surface area, consisting of metal clusters and organic multi-topic linkers. MOFs were highly useful in chemical catalysis because of their unique physical properties, such as high surface area and porosity. These unique properties allow us to use MOFs for integrating the fundamental functional elements needed for the efficient electrocatalytic system: 1) immobilization of high concentration of the molecular catalysts, 2) installation of the redox shuttles for charge transport to and from the catalytic sites, 3) optimization of the mass transport channels through the MOFs pores, and 4) modulation of the catalyst's secondary chemical environment. The notion of using MOF to immobilize high concentrations of molecular electrocatalysts to drive electrochemical reactions was demonstrated. Yet, the modulation of the active-site’s immediate chemical environment to boost electrocatalysis rate and selectivity has rarely been shown..
Herein we demonstrate that in a FeTCPP-Based 2D MOF, using an heterogeneous incorporation of ligands bearing a fixed cationic charge, one can electrostatically-stabilize FeTCPP-bound COO- intermediate, and thus systematically tune its CO2-to-CO selectivity up to practically 100%. As such, we believe that these results will widen our understanding of MOF-based electrocatalytic systems and accelerate their implementation is energy-conversion schemes.