Electrochemistry
PVP lets SECCM map Pt OER in concentrated KOH
Open access · cc by · source: Europe PMC
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.
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.
Key findings
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.
Methodology
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.
Limitations
The ranking is for polycrystalline Pt grains in PVP-containing KOH, not a single-crystal rotating-disk Tafel study without polymer additive.
How this study connects
Role on claims
Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.
The same CV family is used to quantify a practical problem — droplet wetting — before mapping catalysis. Unmodified 1 M KOH SECCM droplets wet about 7× the tip diameter; 0.1% PVP cut the wetting factor to about 1.2×, enabling grain-resolved OER on polycrystalline Pt in which (110) and (111) outrank (100) at pH 13.8, unlike common acidic rankings.
Evidence for the claim as stated.
Length scale and electrolyte change the ranking CV is allowed to report. ITO looks partly inert in macroscale CV and uniformly active at 50 nm; Pt OER facet order in PVP-containing pH 13.8 KOH is not the acidic single-crystal order. Quoting a k⁰ or a facet ranking without the length scale and wetting chemistry is the disagreement.
Evidence for the claim as stated.
This library holds 3 empirical chemistry papers on seccm with isolated findings, rates or spectra rather than reviews.
Evidence for the claim as stated.
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.
Evidence for the claim as stated.
Droplet wetting and electrolyte composition change which sites you actually interrogate.
Evidence for the claim as stated.
Open questions
Tensions this paper is part of
From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.
Length scale and electrolyte change the ranking CV is allowed to report. ITO looks partly inert in macroscale CV and uniformly active at 50 nm; Pt OER facet order in PVP-containing pH 13.8 KOH is not the acidic single-crystal order. Quoting a k⁰ or a facet ranking without the length scale and wetting chemistry is the disagreement.
Droplet wetting and electrolyte composition change which sites you actually interrogate.
Related papers in this topic
Same topic cluster — not a recommendation engine.