Fig. 5

Ex and in situ characterization and catalytic performance of 0.2 Rh/NHPA. a Design principle for the development of HPA-based SACs based on the oxidation potentials of 4 HPAs (gray indicates the initially studied and red the new catalysts); CO DRIFT for b 0.2 Rh/NPMA, c 0.2 Rh/NSMA and d 0.2 Rh/NSTA, oxidation for (c, d) was carried out at 523 K for 1 h under 5% O₂ and reduction was performed using 5% CO for 30 min at 373 K; e k³-weighted EXAFS spectra and f XANES for rhodium foil, Rh₂O₃ and 0.2 Rh/NSTA; g Temperature-activity curves for Rh catalysts (0.2 wt%, 100 mg), GHSV = 24,000 h⁻¹ 1% CO/1% O₂, balance Ar; h ATR-IR spectra for PMA, 0.2 Rh/NPMA before and after CO oxidation up to 300 °C (573 K); i in situ DRIFT spectra for the reoxidation of reduced 0.2 Rh/NPMA under 5% O₂ atmosphere; j activation energies of the Rh catalysts (0.2 wt%) for CO oxidation; k correlation between T₂₀ and oxidation potential of the support