Carboxyl group enhanced CO tolerant GO supported Pt catalysts: DFT and electrochemical analysis

Research output: Contribution to journalArticlepeer-review

Authors

  • M. N. Groves
  • J. Fennell
  • N. Soin
  • S. L. Horswell
  • C. Malardier-Jugroot

Colleges, School and Institutes

External organisations

  • Aarhus Universitet
  • Department of Chemistry, College of Chemistry and Chemical Engineering, and MOE Key Laboratory of Analytical Sciences, Xiamen University, Xiamen 361005, China.
  • Department of Physics and Astronomy
  • Aarhus University
  • Royal Military College of Canada
  • Institute for Renewable Energy and Environmental Technologies (IREET)
  • Knowledge Centre for Materials Chemistry (KCMC)
  • University of Bolton

Abstract

The effect of residual oxygen species in as-prepared Pt nanoparticle on partially reduced graphene oxide (Pt/PRGO) and partially reduced carboxylated-GO (Pt/PR(GO-COOH)) supports was investigated using electrochemical CO stripping and density functional theory (DFT) analysis. Pt/PRGO and Pt/PR(GO-COOH) revealed a clear negative shift in CO-stripping onset potential compared to commercial Pt/carbon black. DFT analysis confirmed that the presence of a -COOH group provides the most resistance for CO adsorption. This CO-Pt binding energy is significantly lower than that observed in the presence of an OH group, which is the most abundant oxygen group in carbon supports. The Pt-CO dissociation energies (on a 42-atom graphene sheet) in the presence of various oxygen groups, in descending order, were OH > C=O ≈ C-O-C > COOH. Although single-bonded carbon-oxygen groups (-OH and C-O-C) are more abundant on the GO basal plane and play an important role in Pt nanoparticle nucleation and distribution on graphene sheets, the double-bonded carbon-oxygen (C=O and COOH) groups are more abundant residual species post Pt nanoparticle growth and play a vital role in enhancing CO tolerance.

Details

Original languageEnglish
Pages (from-to)6142-6151
Number of pages10
JournalChemistry of Materials
Volume26
Issue number21
Publication statusPublished - 11 Nov 2014