4 years ago

In Situ Infrared Spectroscopic Investigations of Pyridine-Mediated CO2 Reduction on Pt Electrocatalysts

In Situ Infrared Spectroscopic Investigations of Pyridine-Mediated CO2 Reduction on Pt Electrocatalysts
Marco Dunwell, Yushan Yan, Bingjun Xu
Pyridine-mediated electrochemical reduction of CO2 has attracted much attention owing to the promise of producing valuable oxygenates with high yields. However, no detectable level of methanol was observed in the pyridine-mediated CO2 electrolysis on Pt over the entire potential range investigated (−0.2 to −0.8 V vs RHE) in this study. Formate was observed at a potential below −0.6 V vs RHE in the absence and presence of pyridine, but the presence of pyridine does accelerate the rate of formate production. Numerous reaction mechanisms have been proposed on the basis of reactivity measurements, cyclic voltammetry, or computational methods; however, a direct experimental mechanistic investigation has been lacking. By employing surface-enhanced infrared absorption spectroscopy, we identified an adsorbed unidentate COOHL intermediate on Pt regardless of the presence of pyridine. Surface coverage of the COOHL intermediate relative to that of adsorbed CO appears to increase with the concentration of pyridine in the electrolyte, which is consistent with the observed production rates for formate and CO. We propose that adsorbed COOHL is a common intermediate in the formation of both formate and CO, and the presence of pyridinium promotes the formate pathway.

Publisher URL: http://dx.doi.org/10.1021/acscatal.7b01392

DOI: 10.1021/acscatal.7b01392

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.