Carbon supported nano-sized Pt–Pd and Pt–Co electrocatalysts for proton exchange membrane fuel cells

Abstract

Nano-sized Pt-Pd/C and Pt-Co/C electrocatalysts have been synthesized and characterized by an alcohol-reduction process using ethylene glycol as the solvent and Vulcan XC-72R as the supporting material. While the Pt-Pd/C electrodes were compared with Pt/C (20 wt.% E-TEK) in terms of electrocatalytic activity towards oxidation of H 2 , CO and H 2-CO mixtures, the Pt-Co/C electrodes were evaluated towards oxygen reduction reaction (ORR) and compared with Pt/C (20 wt.% E-TEK) and Pt-Co/C (20 wt.% E-TEK) and Pt/C (46 wt.% TKK) in a single cell. In addition, the Pt-Pd/C and Pt-Co/C electrocatalyst samples were characterized by XRD, XPS, TEM and electroanalytical methods. The TEM images of the carbon supported platinum alloy electrocatalysts show homogenous catalyst distribution with a particle size of about 3-4 nm. It was found that while the Pt-Pd/C electrocatalyst has superior CO tolerance compared to commercial catalyst, Pt-Co/C synthesized by polyol method has shown better activity and stability up to 60 C compared to commercial catalysts. Single cell tests using the alloy catalysts coated on Nafion-212 membranes with H 2 and O 2 gases showed that the fuel cell performance in the activation and the ohmic regions are almost similar comparing conventional electrodes to Pt-Pd anode electrodes. However, conventional electrodes give a better performance in the ohmic region comparing to Pt-Co cathode. It is worth mentioning that these catalysts are less expensive compared to the commercial catalysts if only the platinum contents were considered.

Nanoporous PtCo and PtNi alloy ribbons for methanol electrooxidation

“…At present, to design and fabricate highly active Pt-based alloy electrocatalysts has been an important strategy by means of engineering the alloy composition, structure size, and morphology etc [6]. For instance, a variety of Pt alloy nanomaterials has been developed to enhance its MOR activity considering the alloy effect, such as PtCu nanoparticles [7], PtRu nanotubes [8], supported PtRu nanoparticles [9e11], PtAu [12] and PtPd [13] nanoparticles and so on. Recently, non-precious 3d transition metals (referring to the unfilled subshell electrons in the 3d-orbital), such as Fe, Co, and Ni, were found to have great synergistic catalytic effect on the MOR activity of Pt [13e16] besides their remarkably synergistic role on oxygen reduction reaction (ORR) [5].…”

“…With the advantages of the activity enhancement and the cost reduction by alloying with the 3d metal, the morphology of these alloy nanomaterials has also attracted great attention by virtue of the structure effect [6]. Some PtCo and PtNi alloy nanostructures, such as carbon supported nanoparticles [13,15,17] and hollow nanospheres [16], have been prepared with the improvement of MOR activity on Pt. Despite the increasing attention on the methanol electrooxidation on Pt-3d metal alloy nanomaterials, investigations on the structure stability of these nanocatalysts and the physically catalytic effect of 3d metals on Pt are relatively lacking.…”

Energy-saving synthesis of electrolytic manganese dioxide using oxygen cathode with Pt/TiO2-CNx nanocatalysts

“…The peaks of the TiO 2 anatase phase occurred at 26°, 34°, and 52° [29,30]. The peaks at 27.3°, 35.9°, and 43.9° were ascribed to the (110), (101), and (111) planes of TiO 2 rutile, respectively [18]; compared with pure TiO 2 , a new peak was observed between 43° and 45°. Huang et al [30] found that the difference between doped TiO 2 /CNTs (700 °C) and pure TiO 2 is the appearance of new peaks between 43° and 45°.…”

“…Nanomaterials and mesoporous materials have attracted enormous attention essentially due to their wide range of application areas, including sensor [10][11][12][13], supercapacitor [14], biosensor [15][16][17], and GDE [18]. The Pt-based nanocatalyst usually was used in acid solution.…”

Promoting hydrogen production by loading PdO and Pt on N–TiO 2 under visible light

“…9). PdOePt structure exhibit electron exchange and transfer ability [15,18,19]. Hence, Reaction (4) proceeds more easily when loading PdO and Pt nanoparticles than when loading only Pt or PdO, explaining the increased hydrogen gas yield attained when both PdO and Pt nanoparticles were used.…”