ETDs @PUC-Rio
| Título: | INFLUENCE OF SYNTHESIS CONDITIONS ON PHYSICOCHEMICAL PROPERTIES OF SNO2 | ||||||||||||||||||||||||||||||||||||||||
| Autor: |
RENATO MOUTINHO DA ROCHA |
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| Colaborador(es): |
SILVANA BRAUN - Orientador |
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| Catalogação: | 27/OUT/2005 | Língua(s): | PORTUGUESE - BRAZIL |
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| Tipo: | TEXT | Subtipo: | THESIS | ||||||||||||||||||||||||||||||||||||||
| Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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| Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=7368&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=7368&idi=2 |
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| DOI: | https://doi.org/10.17771/PUCRio.acad.7368 | ||||||||||||||||||||||||||||||||||||||||
| Resumo: | |||||||||||||||||||||||||||||||||||||||||
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Preliminary tests on the reaction for formaldehyde
production from metoxi
methane (DME) using a Mo/SnO2 catalyst have indicated the
necessity of highly
active systems. Dispersed species of Mo seem to be the
most effective for this
reaction which may be favored by the use of a support of
high specific area.
Therefore the influence of the synthesis parameters on the
physicochemical
properties of the SnO2 has been studied in this work. This
oxide has been
prepared by three different methods: by the oxidation of
Sn0 using HNO3, by the
reaction of Sn+4 with NH4OH, and by the reaction of Sn+4
with dodecylamine.
Variations on the way of mixing the solutions, on the time
and the temperature of
the reaction, and on the heating rate of the calcinations
step have been carried out.
These samples have been characterized by N2 adsorption for
measurements of
specific area and pore size distributions, X-ray
diffraction and UV-visible diffuse
reflectance spectroscopy. The results have shown that all
samples are mesoporous
even though they have exhibited distinct values of
specific area, crystal size and
HOMO-LUMO gap energy. The reaction of Sn+4 with NH4OH has
presented the
greatest sensitivity to the synthesis parameters, and it
has provided samples with
the highest specific area values. However the samples
prepared by the oxidation
of Sn0 using HNO3 have not been influenced. The results
have also indicated that
the temperature and the reaction time seem to be the most
important parameters.
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