Preference for low-coordination sites by adsorbed CO on small platinum nanoparticles

Abstract

Successfully synthesized PVP stabilized Pt NPs from 1.4 to 4.8 nm. Two new bands at 2021 cm−1 and 1994 cm−1 were observed in the FTIR spectra of adsorbed 12CO on Pt NPs which are assigned to the edge and corner sites at Pt surface respectively.

Nitrile hydrogenation to secondary amines under ambient conditions over palladium–platinum random alloy nanoparticles

“…The monometallic Pt nanoparticles showed a strong peak at 2048 cm −1 and a weak peak at around 1750–1900 cm −1 ; these peaks were assigned to CO adsorbed on linear and bridge sites composed of metallic Pt species, respectively (Pt 0 –CO linear and Pt 0 –CO bridge ). 43,44 In contrast, the spectrum of the 3.9 nm PdPt (50 : 50) nanoparticles showed two representative absorption peaks: one at 2035 cm −1 and another at around 1750–1950 cm −1 . The former peak was assigned to Pt 0 –CO linear , and because the latter peak is located between the peaks observed for the monometallic Pd and Pt nanoparticles, it can probably be assigned to CO adsorbed on bridge and three-fold hollow sites composed of both Pd 0 and Pt 0 species.…”

Continuous CO2 Capture and Selective Hydrogenation to CO over Na-Promoted Pt Nanoparticles on Al2O3

“…For Pt/Al 2 O 3 , two small peaks at 2102 and 2082 cm −1 , assignable to the linearly adsorbed ontop CO on terrace-like sites of Pt NPs 43 (corresponding to well-coordinated (WC) Pt sites 44 ) were observed with the main band derived from the on-top CO on step-like sites of Pt NPs 43 (under-coordinated Pt sites 44 ) at approximately 2065 cm −1 . For Pt−Na/Al 2 O 3 , the peak derived on terrace-like sites was hardly observed, and a broad band appeared at approximately 2000 cm −1 , which is assigned to the on-top CO adsorbed near edges and vertices 45 (highly undercoordinated Pt sites 44 ). For Pt−Mg/Al 2 O 3 , the band derived from bridge CO on two Pt atoms was observed at approximately 1800 cm −1 .…”

Nanoparticle formation in nanoporous structures and applications

“…This may change the internal degrees of freedom of the particle because of the high inhomogeneity of the surface potentials. Therefore, it can be expected a change in the response of the adsorbed particle to an external excitation, such as a red-shift of the energy levels [93,94].…”