CHEM In the literature: contested

Why hydrogen evolution on platinum slows down in alkaline solution

In plain words

Platinum makes hydrogen from water roughly a hundred times more slowly in basic solution than in acid. The reason for this slowdown is still disputed.

Precise statement

Explain the drop of the exchange current density of the hydrogen evolution and oxidation reactions on Pt from pH 0 to pH 13 (about two orders of magnitude), distinguishing between hydrogen binding energy shifts, the interfacial water reorganization and the potential of zero free charge, and cation-hydroxyl interactions. An answer is a model that predicts the measured rate versus pH and versus cation identity.

What would settle it

pH- and cation-resolved kinetics on single-crystal Pt with in situ spectroscopy, matched by constant-potential simulations of the proton or water discharge step.

See also