Figure 16.

Operando IR spectroscopy reveals the occurrence of CO-induced surface reconstruction of Pt NPs as a function of the temperature and under reaction conditions. (a) Evolution of in situ DRIFT spectra of CO adsorbed at the saturation coverage on a Pt/Al₂O₃ catalyst (average particle size 17 nm) as a function of time and temperature. Adapted with permission from ref (33). Copyright 2017 American Chemical Society. (b) Wulff construction of a 9.2 nm Pt NP based on DFT-calculated free energies for bare surfaces (bottom) and CO-saturated surfaces (top). WC Pt atoms are represented in green, and UC Pt sites are in blue. Adapted with permission from ref (33). Copyright 2017 American Chemical Society. (c) DRIFT spectrum of a Pt/Al₂O₃ catalyst (average particle size 19 nm) in the presence of CO at room temperature (saturation coverage, prereaction), and its evolution under CO oxidation reaction conditions (1% CO, 1% O₂) as a function of time and temperature. Adapted with permission from ref (237). Copyright 2016. American Chemical Society.