Aiming at speeding up the discovery and understanding
of promising
electrocatalysts, a novel experimental platform,i.e., theNano Lab, is introduced. It is based on state-of-the-art
physicochemical characterization and atomic-scale tracking of individual
synthesis steps as well as subsequent electrochemical treatments targeting
nanostructured composites. This is provided by having the entire experimental
setup on a transmission electron microscopy (TEM) grid. Herein, the
oxygen evolution reaction nanocomposite electrocatalyst, i.e., iridium
nanoparticles dispersed on a high-surface-area TiOxNysupport prepared on the Ti TEM
grid, is investigated. By combining electrochemical concepts such
as anodic oxidation of TEM grids, floating electrode-based electrochemical
characterization, and identical location TEM analysis, relevant information
from the entire composite’s cycle,i.e., from
the initial synthesis step to electrochemical operation, can be studied.
We reveal that Ir nanoparticles as well as the TiOxNysupport undergo dynamic changes
during all steps. The most interesting findings made possible by theNano Labconcept are the formation of Ir single atoms and
only a small decrease in the N/O ratio of the TiOxNy–Ir catalyst during the
electrochemical treatment. In this way, we show that the precise influence
of the nanoscale structure, composition, morphology, and electrocatalyst’s
locally resolved surface sites can be deciphered on the atomic level.
Furthermore, theNano Lab’s experimental setup
is compatible withex situcharacterization and other
analytical methods, such as Raman spectroscopy, X-ray photoelectron
spectroscopy, and identical location scanning electron microscopy,
hence providing a comprehensive understanding of structural changes
and their effects. Overall, an experimental toolbox for the systematic
development of supported electrocatalysts is now at hand.