Electrochemically Triggered Dynamics within a Hybrid Metal-Organic Electrocatalyst

A wide array of systems, ranging from enzymes to synthetic catalysts, exert adaptive motifs to maximize their functionality. In a related manner, select metal-organic frameworks (MOFs) and similar systems exhibit structural modulations under stimuli such as the infiltration of guest species. Probing their responsive behavior in situ is a challenging but important step toward understanding their function and subsequently building functional systems. In this report, we investigate the dynamic behavior of an electrocatalytic Mn-porphyrin-containing MOF system (Mn-MOF). We discover, using a combination of electrochemistry and in situ probes of UV-vis absorption, resonance Raman, and infrared spectroscopy, a restructuration of this system via a reversible cleavage of the porphyrin carboxylate ligands under an applied voltage. We further show, by combining experimental data and DFT calculations, as a proof of concept, the capacity to utilize the Mn-MOF for electrochemical CO2 fixation and to spectroscopically capture the reaction intermediates in its catalytic cycle. The findings of this work and the methodology developed open opportunities in the application of MOFs as dynamic, enzyme-inspired electrocatalytic systems.