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Influência do agente precipitante na preparação do óxido de nióbio (V) hidratado pelo método da precipitação em solução homogênea

2005; Brazilian Chemical Society; Volume: 28; Issue: 2 Linguagem: Inglês

10.1590/s0100-40422005000200016

1678-7064

Gerônimo Virginio Tagliaferro, M. Silva, Gilberto L. J. P. da Silva,

Catalysis and Oxidation Reactions

HOMOGENEOUS PRECIPITATION.This work reports the preparation, characterization and study of the ion exchange behavior of hydrous niobium oxide prepared by a homogeneous precipitation method.The precipitating agent was obtained in aqueous solution by thermal decomposition of urea or ammonium carbonate.The compounds were chemically and physically characterized by X-ray diffractometry, thermal analysis (TG/DTG), surface area measurements and ion exchange behavior with sodium.The materials prepared with ammonium carbonate presented a higher degree of crystallinity and better ion exchange capacity with sodium than materials prepared with urea.In the homogeneous precipitation method, materials were obtained with specific surface area of 123 -224 m 2 g -1 .A variation of the preparation process produced hydrous niobium oxide with a different degree of hydration and specific surface area.This provided materials with different physico-chemical properties.