  Anti-icing coatings are intended to prevent ice formation on surfaces,
minimising the risk of surface-related damage and also reducing ice-related
hazards in society. $\mathrm{CeO}_{2}$ coatings are robust, hydrophobic, and
transmit light, thus they are suitable for a range of applications. However,
their evolving surface chemistry during the initial stages of
$\mathrm{H}_{2}\mathrm{O}$ exposure at very low temperatures has not been
investigated, despite that this is important for understanding their anti-icing
properties. To study this, $\mathrm{CeO}_{2}$ coatings were grown by sputter
deposition, cooled to $\approx100\,$K and exposed to a
$\mathrm{H}_{2}\mathrm{O}$ atmosphere at $1\times10^{-8}\,\mathrm{mbar}$. We
demonstrate the usefulness of X-ray photoelectron spectroscopy (XPS) as a tool
for investigating the anti-icing properties of surfaces. We present XPS
measurements of $\mathrm{CeO}_{2}$ coatings before and after exposure to
$\mathrm{H}_{2}\mathrm{O}$, in-situ and at cryogenic temperatures. XPS reveals
that little to no ice forms on the surface of $\mathrm{CeO}_{2}$ after the
$\mathrm{H}_{2}\mathrm{O}$ exposure at $\approx100\,$K. In contrast, ice was
observed all over the sample holder on which the $\mathrm{CeO}_{2}$ was
mounted. These findings suggest that $\mathrm{CeO}_{2}$ is a promising
candidate for future anti-icing coatings.
