CO and O2 Adsorption and CO Oxidation on Pt Nanoparticles by Indirect Nanoplasmonic Sensing

We used indirect nanoplasmonic sensing (INPS) coupled with mass spectrometry to study CO and oxygen adsorption as well as CO oxidation, on Pt nanoparticles, in the Torr pressure range. Due to an optimization of the physical parameters of our plasmonic sample, we obtain a highly sensitive probe that can detect gas adsorption of a few hundredths of a monolayer, even with a very low number density of Pt particles. Moreover and for the first time, a similarity is observed between the sign and the evolution of the localized surface plasmon resonance (LSPR) peak shift and the work function measurements for CO and oxygen chemisorption. Controlling the size, shape, and surface density of Pt particles, the turnover frequency (TOF) has also been accurately determined. For similar experimental conditions, the TOF is close to those measured on Pt/oxide powder catalysts and Pt(100) single crystals.

Automated summary

Using indirect nanoplasmonic sensing coupled with mass spectrometry, we studied CO and oxygen adsorption as well as CO oxidation on Pt nanoparticles in the Torr pressure range. By optimizing the physical parameters of our plasmonic sample, we obtained a highly sensitive probe capable of detecting gas adsorption at low Pt particle density. We also observed a similarity between LSPR peak shift and work function measurements for CO and oxygen chemisorption, and accurately determined the turnover frequency by controlling the size, shape, and surface density of Pt particles.