XPS/STM study of model bimetallic Pd–Au/HOPG catalysts

• DOI: 10.1016/j.apsusc.2016.01.173
• Publication Date: 2016-01-21T02:21:29Z
• Authors: Andrey V. Bukhtiy...; Igor P. Prosvirin; Valerii I. Bukhti...
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract The preparation of model bimetallic Pd–Au/HOPG catalysts has been investigated using scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) techniques. Initially, model “core–shell” type Pd–Au/HOPG catalysts with similar particle size distribution (5–8 nm), but with different densities of particle locations on the HOPG surface and Pd/Au atomic ratios are prepared. Further, their thermal stability is studied within a temperature range of 50–500 °C at UHV conditions. It has been shown that annealing the model catalysts at a temperature range of 300–400 °C leads to formation of Pd–Au alloyed particles. Enhancement of heating temperature up to 500 °C results in sintering of bimetallic nanoparticles. Contribution of different parameters controlling the properties of Pd–Au alloyed particles has been discussed.