Iron Porphyrin Allows Fast and Selective Electrocatalytic Conversion of CO2 to CO in a Flow Cell

Molecular catalysts have been shown to have high selectivity for CO2 electrochemical reduction to CO, but with current densities significantly below those obtained with solid‐state materials. By depositing a simple Fe porphyrin mixed with carbon black onto a carbon paper support, it was possible to...

Full description

Saved in:
Bibliographic Details
Published in:Chemistry : a European journal 2020-03, Vol.26 (14), p.3034-3038
Main Authors: Torbensen, Kristian, Han, Cheng, Boudy, Benjamin, Wolff, Niklas, Bertail, Caroline, Braun, Waldemar, Robert, Marc
Format: Article
Language:English
Subjects:
Black carbon
Carbon black
Carbon dioxide
carbon dioxide reduction
Carbon monoxide
Catalysts
Chemical reduction
Chemistry
Current density
Electrochemistry
Energy conversion efficiency
Energy efficiency
Fe complex
flow cell
hybrid materials
Iron
Noble metals
pH effects
Selectivity
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Molecular catalysts have been shown to have high selectivity for CO2 electrochemical reduction to CO, but with current densities significantly below those obtained with solid‐state materials. By depositing a simple Fe porphyrin mixed with carbon black onto a carbon paper support, it was possible to obtain a catalytic material that could be used in a flow cell for fast and selective conversion of CO2 to CO. At neutral pH (7.3) a current density as high as 83.7 mA cm−2 was obtained with a CO selectivity close to 98 %. In basic solution (pH 14), a current density of 27 mA cm−2 was maintained for 24 h with 99.7 % selectivity for CO at only 50 mV overpotential, leading to a record energy efficiency of 71 %. In addition, a current density for CO production as high as 152 mA cm−2 (>98 % selectivity) was obtained at a low overpotential of 470 mV, outperforming state‐of‐the‐art noble metal based catalysts. Iron porphyrin has been shown to be an exceptionally efficient supported homogeneous catalyst for the conversion of CO2 to CO in water once inserted in a flow cell. From neutral pH to alkaline conditions, selectivities larger than 98 % were systematically obtained, thanks to the high reactivity of the catalyst with CO2 and the low overpotential values that makes the HER pathway unfavorable.
ISSN:0947-6539
1521-3765
DOI:10.1002/chem.202000160