Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxide
Abstract Small organic acids, such as formic or acetic acid, which are well‐known products of the electrochemical CO2 reduction reaction, are often not further reduceable to their respective alcohols. Alcohols are well‐desired chemicals and useful as fuels, since they can be easily purified and prov...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley-VCH
2022-06-01
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| Series: | Electrochemical Science Advances |
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| Online Access: | https://doi.org/10.1002/elsa.202100130 |
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| author | Daniel Winkler Valentin Dietrich Christoph Griesser Niusha Shakibi Nia Eva‐Maria Wernig Martin Tollinger Julia Kunze‐Liebhäuser |
| author_facet | Daniel Winkler Valentin Dietrich Christoph Griesser Niusha Shakibi Nia Eva‐Maria Wernig Martin Tollinger Julia Kunze‐Liebhäuser |
| author_sort | Daniel Winkler |
| collection | DOAJ |
| description | Abstract Small organic acids, such as formic or acetic acid, which are well‐known products of the electrochemical CO2 reduction reaction, are often not further reduceable to their respective alcohols. Alcohols are well‐desired chemicals and useful as fuels, since they can be easily purified and provide a high energy density. Here, we present a combined electrochemical, differential electrochemical mass spectrometry (DEMS), and nuclear magnetic resonance spectroscopy (NMR) study, providing insight in the electro‐reduction of formic acid on Mo2C electrodes, and the corresponding formation of notable amounts of methanol, with a Faraday efficiency of ∼27 % at a high steady state current density of –0.3 mA/cm2 compared to other formic acid electroreduction catalysts, such as Pb or Sn. Intriguingly, we find that formic and acetic acid readily form on native oxide covered Mo2C surfaces in air and especially in humid CO2 atmosphere. We realize that the thin native oxide layer that is ubiquitously present on these electrodes is the key factor for the activation of CO2 and the corresponding formation of formic and acetic acid at the solid/gas interface. Subsequent electrochemical reduction of these two acids at the solid/liquid interface proceeds through direct formation of their respective alcohols. The activity toward organic acid reduction on Mo2C catalysts can therefore be enhanced by their adsorption properties at the surface and not necessarily through inhibition of the HER, which is exceptional and points to a general strength of compound catalysts for organic acid reduction and CO2 activation. |
| first_indexed | 2024-04-12T18:09:13Z |
| format | Article |
| id | doaj.art-73b7fcbb92e5455a929d89f5a307f84c |
| institution | Directory Open Access Journal |
| issn | 2698-5977 |
| language | English |
| last_indexed | 2024-04-12T18:09:13Z |
| publishDate | 2022-06-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | Electrochemical Science Advances |
| spelling | doaj.art-73b7fcbb92e5455a929d89f5a307f84c2022-12-22T03:21:53ZengWiley-VCHElectrochemical Science Advances2698-59772022-06-0123n/an/a10.1002/elsa.202100130Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxideDaniel Winkler0Valentin Dietrich1Christoph Griesser2Niusha Shakibi Nia3Eva‐Maria Wernig4Martin Tollinger5Julia Kunze‐Liebhäuser6Department of Physical Chemistry University of Innsbruck Innsbruck AustriaDepartment of Organic Chemistry University of Innsbruck Innsbruck AustriaDepartment of Physical Chemistry University of Innsbruck Innsbruck AustriaDepartment of Physical Chemistry University of Innsbruck Innsbruck AustriaDepartment of Physical Chemistry University of Innsbruck Innsbruck AustriaDepartment of Organic Chemistry University of Innsbruck Innsbruck AustriaDepartment of Physical Chemistry University of Innsbruck Innsbruck AustriaAbstract Small organic acids, such as formic or acetic acid, which are well‐known products of the electrochemical CO2 reduction reaction, are often not further reduceable to their respective alcohols. Alcohols are well‐desired chemicals and useful as fuels, since they can be easily purified and provide a high energy density. Here, we present a combined electrochemical, differential electrochemical mass spectrometry (DEMS), and nuclear magnetic resonance spectroscopy (NMR) study, providing insight in the electro‐reduction of formic acid on Mo2C electrodes, and the corresponding formation of notable amounts of methanol, with a Faraday efficiency of ∼27 % at a high steady state current density of –0.3 mA/cm2 compared to other formic acid electroreduction catalysts, such as Pb or Sn. Intriguingly, we find that formic and acetic acid readily form on native oxide covered Mo2C surfaces in air and especially in humid CO2 atmosphere. We realize that the thin native oxide layer that is ubiquitously present on these electrodes is the key factor for the activation of CO2 and the corresponding formation of formic and acetic acid at the solid/gas interface. Subsequent electrochemical reduction of these two acids at the solid/liquid interface proceeds through direct formation of their respective alcohols. The activity toward organic acid reduction on Mo2C catalysts can therefore be enhanced by their adsorption properties at the surface and not necessarily through inhibition of the HER, which is exceptional and points to a general strength of compound catalysts for organic acid reduction and CO2 activation.https://doi.org/10.1002/elsa.202100130CO2 activationDEMSelectrocatalysisformic acid reductionMo2CNMR |
| spellingShingle | Daniel Winkler Valentin Dietrich Christoph Griesser Niusha Shakibi Nia Eva‐Maria Wernig Martin Tollinger Julia Kunze‐Liebhäuser Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxide Electrochemical Science Advances CO2 activation DEMS electrocatalysis formic acid reduction Mo2C NMR |
| title | Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxide |
| title_full | Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxide |
| title_fullStr | Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxide |
| title_full_unstemmed | Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxide |
| title_short | Formic acid reduction and CO2 activation at Mo2C: The important role of surface oxide |
| title_sort | formic acid reduction and co2 activation at mo2c the important role of surface oxide |
| topic | CO2 activation DEMS electrocatalysis formic acid reduction Mo2C NMR |
| url | https://doi.org/10.1002/elsa.202100130 |
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