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Pt/SrTiO3 shows promise as a low temperature hydrocarbon combustion catalyst for automotive applications. In this study, SrTiO3 nanocuboid supports were synthesized using sol-precipitation coupled with hydrothermal synthesis, and platinum was deposited on the nanocuboids with 1, 3, and 5 cycles of atomic layer deposition (ALD). The platinum particles have a highly uniform distribution both before and after reaction testing, and range from 1 to 5 nm in size, depending upon the number of ALD cycles. These materials have a >50 °C lower light-off temperature for propane oxidation than a conventional Pt/Al2O3 catalyst, turn over frequencies up to 3 orders of magnitude higher, and show improved resistance to deactivation. The increased activity is attributed to the stabilization of a Pt/PtO core/shell structure during operating conditions by the strong epitaxy between the Pt and the SrTiO3 support.

Raman spectroscopy was used to demonstrate that the lattice dynamics of SrTiO3 (STO) nanoparticles strongly depends on their microstructure, which is in turn determined by the synthetic approach employed. First-order Raman modes are observed at room temperature in STO single-crystalline nanocubes with average edge lengths of 60 and 120 nm, obtained via sol-precipitation coupled with hydrothermal synthesis and a molten salt procedure, respectively. First-order Raman scattering arises from local loss of inversion symmetry caused by surface frozen dipoles, oxygen vacancies, and impurities incorporated into the host lattice. The presence of polar domains is suggested by the pronounced Fano asymmetry of the peak corresponding to the TO2 polar phonon, which does not vanish at room temperature. These noncentrosymmetric domains will likely influence the dielectric response of these nanoparticles.