Publication 889

Science, 365 (6451), 367-369, 2019 DOI:10.1126/science.aax4608
Molecular electrocatalysts can mediate fast, selective CO2 reduction in a flow cell

Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
Université de Paris, Laboratoire d’Electrochimie Moléculaire, CNRS, F-75013 Paris, France
Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
Stewart Blusson Quantum Matter Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1M1, Canada

Abstract
Practical electrochemical carbon dioxide (CO2) conversion requires a catalyst capable of mediating the efficient formation of a single product with high selectivity at high current densities. Solid-state electrocatalysts achieve the CO2 reduction reaction (CO2RR) at current densities ≥ 150 milliamperes per square centimeter (mA/cm2), but maintaining high selectivities at high current densities and efficiencies remains a challenge. Molecular CO2RR catalysts can be designed to achieve high selectivities and low overpotentials but only at current densities irrelevant to commercial operation. We show here that cobalt phthalocyanine, a widely available molecular catalyst, can mediate CO2 to CO formation in a zero-gap membrane flow reactor with selectivities > 95% at 150 mA/cm2. The revelation that molecular catalysts can work efficiently under these operating conditions illuminates a distinct approach for optimizing CO2RR catalysts and electrolyzers.

Highligthed by sciencemag https://science.sciencemag.org/content/365/6451/367

"Flowing CO2 boosts a molecular catalyst" - Jake Yeston, Science
Molecular electrocatalysts for CO2 reduction have often appeared to lack sufficient activity or stability for practical application. Ren et al. now show that design of the surrounding electrochemical cell can substantially boost both features. They directly exposed a known molecular catalyst, cobalt phthalocyanine, to gaseous CO2 in a flow cell architecture, rather than an aqueous electrolyte. The configuration accommodated current densities exceeding 150 milliamperes per square centimeter, with longevity limited by local proton concentration rather than catalyst stability.

Highligthed by UBC  https://science.ubc.ca/news/ubc-u-paris-chemists-discover-new-way-recycle-co2

"UBC, U Paris chemists discover new way to recycle CO2"