PVP lets SECCM map Pt OER in concentrated KOH
A little polyvinylpyrrolidone stops alkaline SECCM droplets from spreading, enabling single-grain OER maps that rank Pt(110)/(111) above (100) at pH 13.8.
Source
Controlling surface wetting in high-alkaline electrolytes for single facet Pt oxygen evolution electrocatalytic activity mapping by scanning electrochemical cell microscopy
Study at a glance
- Design
- Other — SECCM meniscus wetting control with PVP in 1 M KOH and correlative EBSD OER mapping on Pt
- N
- Electrochemical microscopy method — no sample N
- Population
- Polycrystalline Pt grains probed by alkaline SECCM
- Outcome
- Facet-dependent OER currents after wetting-factor control
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Authors quantified wetting of 1 M KOH SECCM menisci with Fc(MeOH)2 voltammetry and FEM, then added 0.02–0.1% PVP to cut the wetting factor and mapped OER on large-grain polycrystalline Pt with correlative EBSD.
What they found
Unmodified 1 M KOH droplets can wet ~7× the tip diameter; 0.1% PVP lowers the wetting factor to about 1.2×. At pH 13.8, OER current density is similar for (110) and (111) and higher than (100), unlike common acidic rankings.
The limits
What it doesn't show
The ranking is for polycrystalline Pt grains in PVP-containing KOH, not a single-crystal rotating-disk Tafel study without polymer additive.
Key terms
- SECCM
- Scanning electrochemical cell microscopy using a nanopipette droplet as a local electrochemical cell.
- Wetting factor (WF)
- Spreading droplet diameter divided by tip-end diameter.
- OER
- Oxygen evolution reaction, water oxidation to O2.
- EBSD
- Electron backscatter diffraction, mapping grain crystallographic orientation.
- PVP
- Polyvinylpyrrolidone added to raise electrolyte surface tension/control wettability.
Flashcards
Research intelligence for this paper
See its role on concept claims, tensions it is part of, placement history, and related discoveries.
Quiz yourself
SECCM droplets in 1 M KOH without PVP wet about:
Common questions
What polymer stabilised alkaline droplets?
PVP (polyvinylpyrrolidone).
What pH was used for Pt OER maps?
pH 13.8.
Which Pt orientations were most OER-active?
(110) and (111), both above (100).
What WF is 1 M KOH without PVP?
About 7.
More on Electrochemistry