Peculiarities of the structure and catalytic behavior of nanostructured Ni catalysts prepared by laser electrodispersion

Resumo

The peculiarities of the structure and catalytic behavior of nickel nanoparticles deposited onto an Al₂O₃ surface by laser electrodispersion (LED) with subsequent activation in carbon monoxide atmosphere has been considered. The reduction of these nanoparticles by in situ treatment in a catalytic cell in Ar + 5% Н2 atmosphere at 150–450°C has been studied using X-ray photoelectron spectroscopy (XPS). It is shown that formation of metal nickel starts by reduction in hydrogen at 300°C. A comparison of catalytic activity of the Ni/Al₂O₃ systems in the catalytic oxidation of CO is carried out. It is found that the preliminary treatment of Ni/Al₂O₃ sample by carbon monoxide leads to an increase in the catalyst efficiency and decrease in the reaction temperature by 50–100°C.