The promoting effect of cesium on structure and morphology of silver catalysts

Anais da Academia Brasileira de Ciências

Marta C. N. A. Carvalho²  Carlos A. Perez²  Renata A. Simão²  Fabio B. Passos¹  Martin Schmal² 

[1] ,Universidade Federal do Rio de JaneiroRio de Janeiro RJ ,Brasil

关键词: silver;    cesium;    catalyst;    AFM;    XPS;    prata;    césio;    catalisador;    AFM;    XPS;   

DOI  :  10.1590/S0001-37652004000100003

来源: SciELO

【 摘 要 】

Silver supported catalysts on alpha-alumina were prepared and characterized by Brunauer-Emmet-Teller equations, scanning electronic microscopy, X-ray diffraction and atomic force microscopy techniques. Results show that these are powerful techniques for the determination of texture, morphology and surface properties. It has been shown that the addition of Cs in the Ag/Al2O3 catalyst increased the dispersion of silver with the formation of small silver particles over a thin silver film already formed over the alumina support. It is important to stress that atomic force microscopy measurements are significant to observe the film and the dispersion of Ag and, on the contrary, X-ray photoelectronic spectroscopy did not, however, it allows to the conclusion that undistinguishable silver, either as metallic or oxidation state, are present at the surface. X-ray diffraction results confirm predominantly metallic silver.

【 授权许可】

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