Caracterização textural e estrutural de V2O5/TiO2 obtidos via sol-gel: comparação entre secagem convencional e supercrítica

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:25Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:45:02Z : No. of bitstreams: 1 2-s2.0-0036519768.pdf: 449177 bytes, checksum: 3de6fa7e337698b4ce898c89a15644bb (MD5) Made available in DSpace on 2014-05-27T11:20:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-03-01 This work describes a modified sol-gel method for the preparation of V 2O 5/TiO 2 catalysts. The samples have been characterized by N 2 adsorption at 77K, x-ray diffractometry (XRD) and Fourier Transform Infrared (FT-IR). The surface area increases with the vanadia loading from 24 m 2 g -1, for pure TiO 2, to 87 m 2 g -1 for 9wt.% of V 2O 5. The rutile form is predominant for pure TiO 2 but became enriched with anatase phase when vanadia loading is increased. No crystalline V 2O 5 phase was observed in the catalysts diffractograms. Two species of surface vanadium observed by FT-IR spectroscopy a monomeric vanadyl and polymeric vanadates, the vanadyl/vanadate ratio remains practically constant. Instituto de Física de São Carlos Universidade de São Paulo, CP 369, 13560-970 São Carlos - SP Departamento de Química Faculdade de Ciências Universidade Estadual Paulista Júlio de Mesquita Filho, CP 473, 17001-970 Bauru - SP Departamento de Química e Bioquímica Instituto de Bioquímica Universidade Estadual Paulista Júlio de Mesquita Filho, CP 510, 18618-000 Botucatu - SP Departamento de Química Faculdade de Ciências Universidade Estadual Paulista Júlio de Mesquita Filho, CP 473, 17001-970 Bauru - SP Departamento de Química e Bioquímica Instituto de Bioquímica Universidade Estadual Paulista Júlio de Mesquita Filho, CP 510, 18618-000 Botucatu - SP