High-Rate and Selective CO2 Electrolysis to Ethylene via Metal–Organic-Framework-Augmented CO2 Availability

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Dae-Hyun Nam
  • Osama Shekhah
  • Adnan Ozden
  • Christopher McCallum
  • Fengwang Li
  • Yanwei Lum
  • Taemin Lee
  • Jun Li
  • Joshua Wicks
  • Andrew Johnston
  • David Sinton
  • Mohamed Eddaoudi
  • Edward H. Sargent

Detail(s)

Original languageEnglish
Article number2207088
Journal / PublicationAdvanced Materials
Volume34
Issue number51
Online published17 Oct 2022
Publication statusPublished - 22 Dec 2022
Externally publishedYes

Abstract

High-rate conversion of carbon dioxide (CO2) to ethylene (C2H4) in the CO2 reduction reaction (CO2RR) requires fine control over the phase boundary of the gas diffusion electrode (GDE) to overcome the limit of CO2 solubility in aqueous electrolytes. Here, a metal–organic framework (MOF)-functionalized GDE design is presented, based on a catalysts:MOFs:hydrophobic substrate materials layered architecture, that leads to high-rate and selective C2H4 production in flow cells and membrane electrode assembly (MEA) electrolyzers. It is found that using electroanalysis and operando X-ray absorption spectroscopy (XAS), MOF-induced organic layers in GDEs augment the local CO2 concentration near the active sites of the Cu catalysts. MOFs with different CO2 adsorption abilities are used, and the stacking ordering of MOFs in the GDE is varied. While sputtering Cu on poly(tetrafluoroethylene) (PTFE) (Cu/PTFE) exhibits 43% C2H4 Faradaic efficiency (FE) at a current density of 200 mA cm2 in a flow cell, 49% C2H4 FE at 1 A cm2 is achieved on MOF-augmented GDEs in CO2RR. MOF-augmented GDEs are further evaluated in an MEA electrolyzer, achieving a C2H4 partial current density of 220 mA cm−2 for CO2RR and 121 mA cm−2 for the carbon monoxide reduction reaction (CORR), representing 2.7-fold and 15-fold improvement in C2H4 production rate, compared to those obtained on bare Cu/PTFE.

Research Area(s)

  • electrochemical CO2 reduction, ethylene production, gas-diffusion electrodes, metal–organic frameworks, reticular chemistry

Citation Format(s)

High-Rate and Selective CO2 Electrolysis to Ethylene via Metal–Organic-Framework-Augmented CO2 Availability. / Nam, Dae-Hyun; Shekhah, Osama; Ozden, Adnan et al.
In: Advanced Materials, Vol. 34, No. 51, 2207088, 22.12.2022.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review