Characterisation of platinum-based fuel cell catalyst materials using 195Pt wideline solid state NMR.

This study demonstrates the utility of the novel Field Sweep Fourier Transform (FSFT) method for acquiring wideline (195)Pt NMR data from various sized Pt nanoparticles, Pt-Sn intermetallics/bimetallics used to catalyse oxidative processes in fuel cell applications, and various other related Pt3X alloys (X = Al, Sc, Nb, Ti, Hf and Zr) which can facilitate oxygen reduction catalysis. The (195)Pt and (119)Sn NMR lineshapes measured from the PtSn intermetallic and Pt3Sn bimetallic systems suggest that these are more ordered than other closely related bimetallic alloys; this observation is supported by other characterisation techniques such as XRD. From these reconstructed spectra the mean number of atoms in a Pt nanoparticle can be accurately determined, along with detailed information regarding the number of atoms present effectively in each layer from the surface.