Study of surface effects and catalytic properties of selected Ni-based bimetallic nanoparticles by Knudsen effusion mass spectrometry

Abstract

Surface effects and catalytic properties of CuNi, AgNi and AuNi bimetallic nanoparticles having diameter 10–30 nm were studied by Knudsen effusion mass spectrometry. The nanoalloys were prepared by solvothermal synthesis using oleylamine. Gradual removing of the organic substances, present on the nanoparticles from the synthesis, accompanied by their oxidation was observed during slow heating. The nanoparticle catalytic activity leading to the oxidation of the organic surface layer to CO2 in final step depends on the selected element in the Ni-based nanoalloy. The CuNi system shows the highest catalytic activity while the AuNi system the smallest one. As demonstrated, the KEMS method can be applied with advantage as a progressive tool for the evaluation of the oxidation catalytic activity of metal nanoparticles. The surface effects and the catalytic properties are discussed in view of our previous studies.