Otro
Oxide surface modification: Synthesis and characterization of zirconia-coated alumina
Registro en:
Journal of Colloid and Interface Science, v. 343, n. 1, p. 256-262, 2010.
0021-9797
9848311210578810
5209978120430790
4361220072322558
1387043320265189
3814895410100282
9491111903657879
1025598529469393
Autor
Dalmaschio, Cleocir José
Mastelaro, Valmor Roberto
Nascente, Pedro Augusto de Paula
Bettini, Jeferson
Zotin, José Luiz
Silva, Elson Longo da
Leite, Edson Roberto
Resumen
Four aluminas were used as supports for impregnation with a zirconium oxide with the aim to achieve a coating, without phase separation, between support and modifier. The supports were impregnated with different concentrations of zirconium aqueous resin, obtained through the polymeric precursor method. After impregnation the samples were calcined and then characterized by XRD, which led to identification of crystalline zirconia in different concentrations from each support used. Using a simple geometric model the maximum amount of surface modifier oxide required for the complete coating of a support with a layer of unit cells was estimated. According to this estimate, only the support should be identified below the limit proposed and crystalline zirconium oxide should be identified above this limit when a complete coating is reached. The results obtained from XRD agree with the estimated values and to con- firm the coating, the samples were also characterized by EDS/STEM, HRTEM, XPS, and XAS. The results showed that the zirconium oxide on the surface of alumina support reached the coating in the limit of 15 Zr nm2 , without the formation of the ZrO2 phase. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)