Self-terminating electrodeposition of Pt on WC electrocatalysts
- Argonne National Lab. (ANL), Argonne, IL (United States); Lam Research, Tualatin, OR (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Columbia Univ., New York, NY (United States)
- National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)
Self-terminated electrochemical deposition is used to grow Pt nanoparticles on tungsten monocarbide (WC) from a pH 4 electrolyte of 3 mmol/L K2PtCl4-0.5 mol/L NaCl. An unconventional potentiodynamic deposition program is used where nucleation is promoted at large over potentials followed by growth termination at still larger over potentials to yield a high coverage of Pt nanoparticles. Following three deposition cycles between –0.8 VSCE and –0.45 VSCE, the surface is covered by a monolayer equivalent charge of Pt in the form of ≈3×1011 particles/cm2 that are ≈6.7 ± 1.1 nm in diameter. The number and size of nanoparticles increase monotonically for five deposition cycles. Area-normalized kinetics for hydrogen evolution (HER) and oxidation (HOR) on Pt-WC were determined in 0.5 mol/L H2SO4. For the lowest surface coverage of Pt nanoparticles on WC, ≈ 0.01, an exchange current density of ≈ 100 mA/cm2 is achieved, comparable to the highest reported values for Pt nanoparticles and ultra microelectrodes. The area normalized apparent exchange current density decreases with increasing Pt coverage as the relative contribution of point versus planar diffusion decreases. Self-terminated electrodeposition of Pt provides an attractive approach to achieving ultra-low loadings of well-dispersed Pt nanoparticles on a non-precious metal support like WC.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- Columbia University; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; University of Delaware; National Institute of Standards and Technology (NIST)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1579193
- Alternate ID(s):
- OSTI ID: 1776966
- Journal Information:
- Applied Surface Science, Vol. 504, Issue C; ISSN 0169-4332
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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