| Texto completo | |
| Autor(es): |
da Silva, Alisson H. M.
[1]
;
Rodrigues, Thenner S.
[2]
;
da Silva, Anderson G. M.
[2]
;
Camargo, Pedro H. C.
[2]
;
Gomes, Janaina F.
[1]
;
Assaf, Jose M.
[1]
Número total de Autores: 6
|
| Afiliação do(s) autor(es): | [1] Univ Fed Sao Carlos, Dept Engenharia Quim, BR-13565905 Sao Carlos, SP - Brazil
[2] Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, Ave Prof Lineu Prestes, 748, BR-05508000 Sao Paulo, SP - Brazil
Número total de Afiliações: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Materials Science; v. 52, n. 24, p. 13764-13778, DEC 2017. |
| Citações Web of Science: | 4 |
| Resumo | |
Here, we have systematically investigated how the nature of the support influenced the oxygen mobility and activities in catalysts comprised of AgPt nanoshells deposited over inorganic oxides. We first synthesized AgPt nanoshells by galvanic replacement reaction between Ag nanospheres and PtCl6 (2-) ((aq)) combined with Pt reduction using hydroquinone as an auxiliary reducing agent. The nanoshells were then supported over TiO2, Al2O3 and CeO2. Through this methodology, we prepared materials with similar metallic nanoparticle AgPt compositions (similar to 0.99 wt% Pt), sizes (43 +/- 2 nm diameter), spherical shapes, surface morphologies, number of active sites and uniform distribution over the supports, differing only in terms of the nature of the support. The oxide reduction temperature, its capability of re-oxidation and the presence of oxygen mobility were strongly dependent on the metal-support interaction between AgPt nanoshells and oxide supports. These properties have significantly influenced their catalytic performances toward the CO oxidation. At 230 A degrees C, the CO oxidation TOF was 40.4 +/- 0.4, 6.9 +/- 1, 1.4 +/- 0.8 min(-1) for AgPt/CeO2, AgPt/TiO2, AgPt/Al2O3, respectively. These differences were attributed to the concentration of oxygen vacancies in each catalyst, which presented exactly the same trend as that of the catalytic activities. Our results may have important contributions to the design of highly active metal oxide-based catalysts toward gas-phase oxidation transformations. (AU) | |
| Processo FAPESP: | 15/06246-7 - Aplicação do conceito de biorrefinaria a estações de tratamento biológico de águas residuárias: o controle da poluição ambiental aliado à recuperação de matéria e energia |
| Beneficiário: | Marcelo Zaiat |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |