Light‐Induced Dispersion of Pd Single Atoms Provides Steady‐State‐Stabilized Activity for Photocatalytic H ₂ Generation

thin-film platform, under a constant, sufficiently high photon flux, a highly dispersed and highly active SA configuration can be maintained, i.e., agglomeration to nanoparticles and activity loss can be prevented. We ascribe this, supported by DFT, to the destabilizing effect of a high hydrogen loading on Pd 2D rafts consisting of few atoms and the high mobility of the Pd-H intermediates. This, in contrast to Pt, provides an energetics that allows to maintain a dispersion-aggregation equilibrium, which results in a steady-state that macroscopically can provide a remarkably high SA-stability during photocatalytic experiments, maintaining the photocatalyst in a state of highest activity.