Structural Dependence of Platinum Nanostructures on Catalytic Performance in Aromatic Azo Compound Reaction Investigated by X-ray Absorption Fine Structure Spectroscopy

Abstract

Uniform one-dimensional Pt nanowires prepared by etching FePt nanowires precursor exhibit high conversion yields and selectivity in aromatic azo compounds reaction compared to the other Pt-based catalysts, such as Pt nanorods and Pt nanoparticles. The X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) were employed to investigate the electronic structure and short-range local environment of the three Pt nanostructures, revealing that the high density of unsaturated coordinated atoms in the short-range local structure of Pt nanowires contribute to the superior catalytic performance of the nanowires. Furthermore, the quasi in-situ XANES was carried out to monitor the electronic structural evolution of the Pt nanowires during the different stages in the whole reaction process, which further clarify the Pt-OH involved catalytic reaction mechanism. This work delineates the correlation between catalytic performance and structural sensitivity of Pt-based catalysts investigated by X-ray absorption spectroscopy.