Carboxyl Group Enhanced CO Tolerant GO Supported Pt Catalysts: DFT and Electrochemical Analysis

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.

Facile Strategy to Fabricate Uniform Black TiO2 Nanothorns/Graphene/Black TiO2 Nanothorns Sandwichlike Nanosheets for Excellent Solar‐Driven Photocatalytic Performance

“…We annealed the as‐prepared sample in nitrogen and hydrogen atmosphere, respectively. From Figure A we can clearly observe only one main peak at 2 θ =26°, which is characteristic of the parallel graphene . No other peaks can be distinguished.…”

Remarkable enhancement of the specific activities of Pt catalysts to methanol oxidation through tuning the surface properties of supporting materials by fast microwave treatments

“…The peak value of carbonyl and carboxyl group is most obvious while hydroxyl/phenolic groups are reduced largely from Pt-RGO/PF-5 to Pt-RGO/PF-10. According to the references [6,7], the hydroxyl/phenolic groups provide suitable positions for Pt nanoparticles nucleation and adsorption. Therefore, the small size and uniformly distributed Pt nanoparticles disclosed by the TEM and XRD experiments of Pt-RGO/PF-3 and Pt-RGO/PF-5 can be considered as the results of high content of hydroxyl/phenolic groups reasonably.…”

“…Thus, their surface properties will have a crucial influence on the achievements of Pt-based catalysts. The results of CO electrochemical stripping experiments and density functional theory (DFT) calculation indicate that the double-bonded carbon-oxygen groups on controlled reduced graphene oxide (RGO) can benefit the antipoisonous abilities of Pt to CO [6,7]. The authors in the research [8] proposed that the sites of oxygen defect on RGO sheets boom the activities of Pt to MOR in a similar mechanism which was found in Pt/RuO 2 .…”

3-D vertically aligned few layer graphene – partially reduced graphene oxide/sulfur electrodes for high performance lithium–sulfur batteries

“…3(a)). 41,[43][44][45][46][47] These residual groups have been previously suggested to immobilise sulfur and subsequently free lithium polysuldes during the charging-discharging process. 24,38,48 Furthermore, peaks attributed to -S-Obonding were observed in both the S 2p (164.6 and 165.5 eV) and O 1s spectrum ($530.6 eV, Fig.…”