Figure 20.

In situ IR spectroscopy and INS allow the identification of several types of Pt–H species on Pt NPs. (a) In situ IR spectrum of a freshly reduced Pt/Al₂O₃ catalyst in the presence of H₂ at 70 °C either in the gas phase (10% H₂ in N₂, 20 mL/min) or in the liquid phase (cyclohexane as solvent). The latter spectrum has been collected in ATR-IR mode. The data reported in (a) are reproduced from ref (242) with permission from the Royal Society of Chemistry. (b) INS spectrum of H₂ chemisorbed on the same reduced Pt/Al₂O₃ catalyst. H₂ was dosed at room temperature at an equilibrium pressure of 420 mbar; the INS spectrum was measured at 20 K in the presence of H₂. Reproduced with permission from ref (319). Copyright 2019 American Chemical Society.