In Situ Raman Study of CO Electrooxidation on Pt(hkl) Single-Crystal Surfaces in Acidic Solution.

Abstract

The adsorption and electrooxidation of CO molecules at well-defined Pt(hkl) single-crystal electrode surfaces is a key step towards addressing catalyst poisoning mechanisms in fuel cells. Herein, we employed in situ electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) coupled with theoretical calculation to investigate CO electrooxidation on Pt(hkl) surfaces in acidic solution. We obtained the Raman signal of top- and bridge-site adsorbed CO* molecules on Pt(111) and Pt(100). In contrast, on Pt(110) surfaces only top-site adsorbed CO* was detected during the entire electrooxidation process. Direct spectroscopic evidence for OH* and COOH* species forming on Pt(100) and Pt(111) surfaces was afforded and confirmed subsequently via isotope substitution experiments and DFT calculations. In summary, the formation and adsorption of OH* and COOH* species plays a vital role in expediting the electrooxidation process, which relates with the pre-oxidation peak of CO electrooxidation. This work deepens knowledge of the CO electrooxidation process and provides new perspectives for the design of anti-poisoning and highly effective catalysts.

• Authors: Min Su, Jin-Chao Dong, Jia-Bo Le, Yu Zhao, Wei-Min Yang, Zhi-Lin Yang, Gary Attard, Guo-Kun Liu, Jun Cheng, Yi-Min Wei, Zhong-Qun Tian, Jian-Feng Li
• Journal: Angewandte Chemie (International ed. in English) (Angew Chem Int Ed Engl) Vol. 59 Issue 52 Pg. 23554-23558 (Dec 21 2020) ISSN: 1521-3773 [Electronic] Germany
• PMID: 32918778 (Publication Type: Journal Article)
• Copyright: © 2020 Wiley-VCH GmbH.