Enhanced Electrochemical CO2 Reduction to Formate on Poly(4-vinylpyridine)-Modified Copper and Gold Electrodes

Chunmiao Ye; Stefan J Raaijman; Xiaoting Chen; Marc T M Koper

doi:10.1021/acsami.2c10452

Enhanced Electrochemical CO₂ Reduction to Formate on Poly(4-vinylpyridine)-Modified Copper and Gold Electrodes

ACS Appl Mater Interfaces. 2022 Oct 12;14(40):45263-45271. doi: 10.1021/acsami.2c10452. Epub 2022 Sep 27.

Authors

Chunmiao Ye¹, Stefan J Raaijman¹, Xiaoting Chen¹, Marc T M Koper¹

Affiliation

¹ Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.

Abstract

Developing active and selective catalysts that convert CO₂ into valuable products remains a critical challenge for further application of the electrochemical CO₂ reduction reaction (CO₂RR). Catalytic tuning with organic additives/films has emerged as a promising strategy to tune CO₂RR activity and selectivity. Herein, we report a facile method to significantly change CO₂RR selectivity and activity of copper and gold electrodes. We found improved selectivity toward HCOOH at low overpotentials on both polycrystalline Cu and Au electrodes after chemical modification with a poly(4-vinylpyridine) (P4VP) layer. In situ attenuated total reflection surface-enhanced infrared reflection-adsorption spectroscopy and contact angle measurements indicate that the hydrophobic nature of the P4VP layer limits mass transport of HCO₃^- and H₂O, whereas it has little influence on CO₂ mass transport. Moreover, the early onset of HCOOH formation and the enhanced formation of HCOOH over CO suggest that P4VP modification promotes a surface hydride mechanism for HCOOH formation on both electrodes.

Keywords: ATR-SEIRAS; Au; CO2RR; Cu; HCOOH; hydrophobic; modification; poly(4-vinylpyridine).