In this work, we
have synthesized through an efficient electrostatic
deposition a Pt single-atom catalyst (SAC) supported on a Ce-MOF.
The basic solution employed in the impregnation process favors the
deprotonation of the hydroxyl groups allocated on the clusters that
can easily interact with the cationic Pt species. The resulting material,
denoted as Pt/UiO-66(Ce), shows an increment of Ce3+content,
as demonstrated by UV–vis and Ce L3-edge XANES spectroscopy.
These Ce3+species and their corresponding oxygen vacancies
are able to accommodate very disperse Pt single sites. Moreover, Pt
L3-edge XANES and CO-FTIR spectroscopy confirm the cationic
nature of the supported Ptδ+(2+ < δ <
4+). For comparison purpose, we have synthesized and characterized
a well-known Pt single-site catalyst supported on nanocrystalline
ceria, denoted as Pt/nCeO2. Since the
simultaneous presence of Ce3+and Ptδ+on the MOF clusters were able to activate the oxygen molecules and
the CO molecule, respectively, we tested Pt/UiO-66(Ce) for the CO
oxidation reaction. Interestingly, this catalyst showed ∼six-fold
increment in activity in comparison with the traditional Pt/nCeO2material. Finally, the characterization
after catalysis reveals that the Pt nature is preserved and that the
activity is maintained during 14 h at 100 °C without any evidence
of deactivation.