In situ FTIR study of surface site transformations in Pd3In/α-Al2O3 and Pd3Ag/α-Al2O3 induced by CO adsorption.

[Display omitted] In the course of the treatment of Pd3Ag/α-Al2O3 in 0.5%CO + He at 200 °C, intense transformation of single atom Pd1 surface sites isolated from each other by Ag atoms to multiatomic Pdn (n ≥ 2) ensembles occurs, as revealed by a rapid increase in the intensity of multibonded CO bands in FTIR spectra. The structure of intermetallic Pd3In nanoparticles is significantly more stable, and the formation of new multiatomic adsorption centers was not observed even after extended CO exposures. [ABSTRACT FROM AUTHOR]