Host-guest tuning of the CO2 reduction activity of an iron porphyrin cage

0563303 - ÚFCH JH 2024 RIV US eng J - Článek v odborném periodiku
Surendran, A. K. - Tripodi, G. L. - Pluhařová, Eva - Pereverzev, A. - Bruekers, J. P. J. - Elemans, J. A. A. W. - Meijer, E. J. - Roithová, J.
Host-guest tuning of the CO2 reduction activity of an iron porphyrin cage.
Natural Science. Roč. 3, č. 1 (2023), č. článku e20220019. ISSN 2150-4091
Institucionální podpora: RVO:61388955
Klíčová slova: electrocatalysis * electrochemistry * CO2 reduction
Obor OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Způsob publikování: Open access

Efficient electrocatalytic CO2 reduction requires developing catalysts with high selectivities and high activities, which is simultaneously difficult to achieve. Here, we present a new approach to tune the CO2 reduction activity based on host-guest chemistry enabled by an iron porphyrin cage catalyst. The cage design allows the hosting of alkali metals in the side walls causing a change in the electrostatic potential inside the cage cavity. Density functional theory calculations show that the guest potassium ions assist the reduction of CO2 by inverting the two-electron transfer from iron(0) to CO2 from endothermic to exothermic. Accordingly, electrochemical experiments with the cage catalyst show that in the presence of the potassium ions, the overpotential for the CO2 reduction decreases, and the catalytic activity increases while the high selectivity of the cage is retained. A novel coupling between the electrochemical cell and a mass spectrometer allowed the trapping of the key intermediates. Cryogenic ion spectroscopy characterization of the intermediates showed the details of the potassium ions hosting in the reduced cage and of the stabilization of the Fe-COOH intermediates by the interaction with the potassium ions at the single-molecule level.

Trvalý link: https://hdl.handle.net/11104/0335302