The effect of CeO₂ on Pt/CeO₂/CNT catalyst for CO electrooxidation

Abstract

Pt/CeO2/CNT catalysts were prepared by adsorbing Pt nanoparticles on the supports of CNTs coated with CeO2. The electrocatalytic performances in respect to the electrooxidation of chemisorbed CO were tested using potential step and stripping voltammetry methods under variable sweep rate and temperature conditions. At 10 mV s–1, the CO stripping voltammogram exhibited the peak splitting phenomenon. The oxidation charge and the peak potential of the two voltammetric peaks changed regularly with the number of Pt and CeO2 neighbours, the sweep rate, and the temperature. We considered that the low potential peak originated from the reaction of COads with hydroxyl groups on CeO2 adjacent to Pt sites, while the high potential peak came from the reaction of COads with hydroxyl groups produced on pure Pt. Furthermore, the experimental results of the peak potential against the logarithm of the sweep rate and the logarithm of the current maximum time against the step potential were plotted and intersecting lines with different slopes in high and low potential regions in the plot were observed. The lines intersected at lower potentials on the Pt/CeO2/CNT electrode than on the Pt/CNT electrode, which was attributed to the contribution of hydroxyl groups on CeO2.

Facile Preparation of an Excellent Pt/RuO2‐MnO2/CNTs Nanocatalyst for Anodes of Direct Methanol Fuel Cells

“…For Pt/MnO 2 / CNTs, the CO electro-oxidation peak was split, instead of one voltammetric peak. The occurrence of the peak splitting may be explained by the participation of hydroxyl groups on MnO 2 , similar with the voltammetric behaviour on PtRu electrode [22]. The peak potential of CO electro-oxidation for Pt/RuO 2 -MnO 2 / CNTs (0.42 V) is also lower than that of Pt/MnO 2 /CNTs (0.57 and 0.68 V).…”

“…At low potentials (<0.29 V), when methanol contacts with Pt, the dissociative adsorption of methanol on Pt via a stepwise dehydrogenation forms CO species attached to the surface of Pt sites, poisoning Pt sites [22,36]. The reaction equation can be written as Eq.…”

“…When the potential rise to 0.29 V, H 2 O molecule can be split by RuO 2 to form oxygen-containing species (-OH ads ) [22]. Then the CO species attached to Pt can be oxidised by the oxygen-containing species to produce carbon dioxide, proton (H + ) and electron (e -).…”

The Promoting Effect of Europium on PtSn/C Catalyst for Ethanol Oxidation

“…To enhance the catalyst activity, the third metal, such as Ru [21], Ni, P and Ir [29][30][31], was added to the binary PtSn catalyst and showed a superior performance. And many oxides of rare earth element with abundant d-orbit such as LnO x (Ln = Sc, Y, La, Ce, Pr and Nd) [32][33][34] were also used to synthesise the Pt-based catalysts for ethanol or methanol electrooxidation. However, the performance of PtSn catalyst modified by rare earth oxides is little reported.…”

The Evidences of Morphology Dependent Electroactivity Toward CO Oxidation over Bismuth Oxide Supported Pt

“…Hayden et al [19] have demonstrated that the particle size of active component and the substrate have great effect on the CO electrocatalytic activity over AuNPs. In addition, the shape effect of carbon material [20][21][22][23][24], such as carbon nanofibers, carbon nanotubes, or ordered mesoporous carbons on the catalytic performance for CO electrooxidation have been widely investigated. Xu et al [25] presented a detailed comparison between multi-walled (MWNT) and single-walled carbon nanotubes (SWNT) for CO-stripping and found a higher tolerance to CO poisoning of Pt in Pt-SWNT/Nafion.…”