Oxygen Reduction Activity and Stability of Composite Pdx/Co-Nanofilms/C Electrocatalysts in Acid and Alkaline Media

Abstract

The morphology tuning of Pd and Pd-M nanoparticles is one of the significant strategies to control the catalytic activity toward oxygen reduction reaction (ORR). In this study, composite Pdx/Co-nanofilms/C electrocatalysts of Pd nanoparticles implanted onto Co nanofilms were synthesized on an immiscible ionic liquid (IL)/water interface for ORR. The Pd nanoparticles implanted onto Co nanofilms show a marked distortion of crystal lattice and surface roughness. These Pdx/Co-nanofilms/C electrocatalysts exhibit enhanced activity for ORR compared with Pd/C and PdxCo/C catalysts in both acid and alkaline solutions, in which the Pd3/Co-nanofilms/C catalyst displays the highest ORR mass activity. The superior ORR mass activities of the fabricated Pdx/Co-nanofilms/C catalysts may be mainly attributed to their larger catalytic areas, which are conferred by the rough surface of Pd nanoparticles with a distorted crystal lattice, and the synergistic effect between the surface Pd atoms and the 2D Co nanofilm substrate. The relationship between ORR mass activity and Pd/Co atom ratio varies in different electrolytes. Furthermore, by using proper heat-treatment methods, the Pdx/Co-nanofilms/C catalysts exhibit improved cycling stability compared with pure Pd/C catalyst after extended potential cycling.

Noble Metal-Added Titanate Nanosheets for PEFC Cathode

“…The enhancement may be due to the doping of Rh into titanate nanosheets. was almost 0.9 V (11), suggesting that our results were almost corresponded to Pd/C. On the other hand, the TiNS:Pd1 shows a drastic increase in the ORR activity compared to TiNs:Pd0.…”

The effect of tensile strain in Pd–Ni core–shell nanocubes with tuneable shell thickness on urea electrolysis selectivity

“…27,47 Similar Ni oxidation onset and peak potentials were observed in the CV of Ni(OH) 2 XG, while Pd NCs showed small activity in the 1.3-1.6 V range associated with the slow oxidation of Pd surface. 48 For all studied anodes, OER wave was observed at more positive potentials than Ni 2+ → Ni 3+ transition. The OER potential at 10 mA cm −2 increased in the following order: Pd NCs < Pd@Ni 0.5 nm < Pd@Ni 1.0 nm , Pd@Ni 1.5 nm < Pd@Ni 2.5 nm < Pd@Ni 10 nm , Ni(OH) 2 XG.…”

“…27,47 Similar Ni oxidation onset and peak potentials were observed in the CV of Ni(OH) 2 XG, while Pd NCs showed small activity in the 1.3–1.6 V range associated with the slow oxidation of Pd surface. 48…”