Zinc(II) Catalyst for the Reduction of CO2 to Formate

  • Author: ChemistryViews.org
  • Published: 23 March 2020
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
  • Source / Publisher: Inorganic Chemistry/ACS Publications
  • Associated Societies: American Chemical Society (ACS), USA
thumbnail image: Zinc(II) Catalyst for the Reduction of CO<sub>2</sub> to Formate

CO2 is a greenhouse gas and a major contributor to climate change. Capturing CO2 and converting it to useful chemicals is one possible approach to control its atmospheric levels. Usually, the capture and the chemical conversion require two separate process steps. In addition, the capture step needs to work at low concentrations of CO2 from the atmosphere or exhaust gas.

Craig A. Grapperhaus, University of Louisville, KY, USA, and colleagues have developed a method that combines these two steps, based on a zinc(II) complex with a redox-active ligand. The catalyst is Zn(DMTH) (pictured, DMTH = diacetyl-2-(4-methyl-3-thiosemicarbazonate)-3-(2-pyridinehydrazonato)). It promotes the reduction of CO2 from air to give formate (HCO2). In methanol, the complex is converted to the active catalyst Zn(HDMTH)(OCH3). This species can fix CO2 from air and form the methylcarbonate intermediate Zn(HDMTH)(CO3CH3). In this compound, CO2 is activated and can react with hydride to give the desired formate and restore methanol and Zn(DMTH).

The ligand–metal interaction helps to activate the CO2 by acting like a frustrated Lewis pair (FLP). FLPs contain a Lewis acid and a Lewis base that cannot combine to form an adduct due to steric hindrance. Many of them can activate small molecules. In the Zn-based catalyst, there is an FLP-like interaction between the Zn(II) ion and the non-coordinating nitrogen of the 2-pyridinehydrazonato group. According to the researchers, the work provides a new approach to CO2 reduction catalysis.



Article Views: 4062

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission and consult our permission guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH