Carbon-supported Pd–Pt cathode electrocatalysts for proton exchange membrane fuel cells

Synthesis and testing of new carbon-supported PdP catalysts for oxygen reduction reaction in polymer electrolyte fuel cells

“…PdFe nanorods exhibited higher performance than pure Pt in a PEMFC at 0.75 V (vs. RHE) [8]. When using PdPt [9,10], Pd 50 Pt 30 Ni 20 [10,11] and Pd 5 Cu 4 Pt [12] cathode electrocatalysts, the PEMFC performance was comparable to that obtained with Pt. However, the cell performances for PdNi [13], PdCu [14], PdMo [15], PdCo, PdPtCo [16], Pd 45 Pt 5 Sn 50 [17] PdCo-ceria [18] were slightly lower than the one obtained with commercial Pt under the same experimental conditions.…”

Surfactant-Free Synthesis of Reduced Graphene Oxide Supported Well-Defined Polyhedral Pd-Pt Nanocrystals for Oxygen Reduction Reaction

“…The smallest crystallite size of the well-defined polyhedral Pd-Pt nanocrystals in Pd 6 Pt 1 /rGO3500-1 sample confirms the fact that the rGO3500-1 substrate with smooth surface (with fewer defects and surface functional groups) and small size (3500 mesh vs. 500 mesh for rGO500-1) is more suitable for the anchoring of small nanocrystals. Moreover, the sizes of Pd-Pt nanocrystals with well-defined morphology in the Pd 6 Pt 1 /rGO500-1 and Pd 6 Pt 1 /rGO3500-1 samples are markedly smaller than their mean particle sizes via the count of nanocrystal sizes in TEM images, which is ascribed to that the polyhedral nanocrystals (specially the 5-fold twinned nanocrystal) consist of more than one crystallite, being demonstrated in our previous works [32,33]. The Raman spectra of the Pd 6 Pt 1 /rGO500-1, Pd 1 Pt 1 /rGO500-1, and Pd 6 Pt 1 /rGO3500-1 ( Figure S6) are similar to those of the GO500-1 and GO3500-1 substrates ( Figure S7), indicating the synthesis of Pd-Pt nanocrystals and the reduction of GO play a small effect in the crystalline structure of graphene sheets.…”

“…were adsorbed on the GO surface via the plus-to-minus charge adsorption between the Pd/Pt complex and the surface functional groups on GO. During the solvothermal process with ethylene glycol as the solvent and reduction agent, tetrahedral, octahedral, and twinned Pd-Pt seeds are prone to be formed due to the present of the ammonia in the system, which has been discussed in our previous works [11,32,33]. Due to the complexation of the metal ions with ammonia as well as the stabilizing effect of GO substrate, the well-defined polyhedral Pd-Pt nanocrystals are formed via slowly growing from the well-defined polyhedral Pd-Pt seeds.…”

“…Moreover, the Pd/Pt ratio also plays important roles in the morphology of Pd-Pt nanocrystals due to the different affinities between the metal (Pd, Pt) and the carbon materials, which have been reported in literatures [33,36]. Figure 4 shows the TEM images of the Pd/rGO3500-1, Pd 3 Pt 1 /rGO3500-1, Pd 1 Pt 1 /rGO3500-1 and Pd 1 Pt 1 /rGO3500-1 for comparison with that of Pd 6 Pt 1 /rGO3500-1 mentioned above.…”

In-situ investigation on the CO tolerance of carbon supported Pd–Pt electrocatalysts with low Pt content by electrochemical impedance spectroscopy

“…The synthesis and physicochemical characterization of the PdePt/C catalysts have been reported in our previous work [24]. The Pd 12 Pt 8 /C (Pd/Pt mass ratio is 3:2, total metal loading is 20 wt.…”