Renewable energy
storage via water electrolysis
strongly depends on the design of electrified electrode–electrolyte
interfaces at which electricity is converted into chemical energy.
At the core of the hydrogen evolution reaction (HER) and the oxygen
evolution reaction conversion efficiency are interfacial processes
with complex dynamic mechanisms, whose further acceleration is practically
impossible without a thorough fundamental understanding of electrocatalysis.
Here, we communicate new experimental insights into HER, which will
potentially further deepen our general understanding of electrocatalysis.
Of special note is the very surprising observation that the most active
metals (i.e., noble metals) for HER, which exhibit
the lowest overpotentials at a defined current density, exhibit the
highest activation energies in comparison to the other metals from
the d-block. This suggests a major, if not dominant, impact of the
frequency factor on activity trends and the need for deeper reconsideration
of the origins of electrocatalytic activity.