We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Surface voltammetric dealloying investigation on PdCu/C electrocatalysts toward ethanol oxidation in alkaline media.
- Authors
Zhu, Chan; Yang, Yao-Yue; Zhao, Zhi-Gang
- Abstract
Voltammetric dealloying is employed here to investigate the correlations between catalytic performance and surface composition and structure, taking ethanol oxidation reaction (EOR) on Pd-Cu alloy surface as a case study. First, home-made PdCu/C with a mean particle size of ca. 3.11 ± 0.6 nm is dealloyed by repetitive potential cycling in 0.5 M H2SO4. With dealloying cycles rising, the Cu component is gradually leached out and the corresponding Pd/Cu atomic ratio gradually increases from ca. 2.1 to 4.0; meanwhile, SEM images display that Pd-rich porous shell is formed due to dealloying-induced surface structural rearrangement, being verified by the appearance of ear-like peaks at − 0.015 V (vs. SCE) in CVs collected in 0.5 M H2SO4; furthermore, XPS spectra indicate that core-level binding energies of Pd 3d5/2 first positively shift to 336.1 eV and then oppositively move down to 334.9 eV, indicating that the d-band center of Pd composition is modulated by the dealloying treatment. Moreover, the voltammetric peak current densities for EOR follow the order of PdCu/C-DA15 > as-prepared PdCu/C ˃ > PdCu/C-DA30 ˃ commercial Pd/C ˃ PdCu/C-DA75, due to the modest downshift of Pd d-band center resulted by charge transfer and surface atomic rearrangement. In addition, the EOR durability gradually decays with the continuous loss of Cu, indicating that electro-oxidation of surface species also follows the so-called bi-functional mechanism. This work might provide some new insights into the catalysis enhancement by tuning the surface/interfacial structure of catalysts.The voltammetric peak current densities for ethanol oxidation on home-made PdCu/C catalysts gradually decrease with the dealloying cycles rising, suggesting that the surface voltammetric dealloyment could effectively modulate the surface composition and structure, so as to tune the catalytic performance.
- Subjects
VOLTAMMETRY; PALLADIUM; ELECTROCATALYSTS; ETHANOL; CHARGE transfer
- Publication
Journal of Nanoparticle Research, 2018, Vol 20, Issue 11, p1
- ISSN
1388-0764
- Publication type
Article
- DOI
10.1007/s11051-018-4423-z