22 documents found, page 1 of 3
Effect of different synthesis methods on the textural properties of calcium tun...
Alencar, Lorena Dariane da Silva; Lima, Naiara Arantes; Mesquita, Alexandre; Probst, Luiz Fernando Dias; Batalha, Daniel CarreiraCalcium tungstate (CaWO4) crystals were prepared by microwave-assisted hydrothermal (MAH) and polymeric precursor methods (PPM). These crystals were structurally characterized by X-ray diffraction (XRD), N2 adsorption, X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) measurements. The morphology and size of these crystals were observed by field emission scanni...
Effect of different synthesis methods on the textural properties of calcium tun...
Da Silva Alencara, Lorena Dariane; Lima, Naiara Arantes; Mesquita, Alexandre [UNESP]; Probst, Luiz Fernando Dias; Batalha, Daniel CarreiraMade available in DSpace on 2018-12-11T17:20:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01. Added 1 bitstream(s) on 2019-10-09T18:31:44Z : No. of bitstreams: 1 S1516-14392018000300037.pdf: 1978270 bytes, checksum: 13347cc24e2927c54c2c95e72ffb1d71 (MD5); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fun...
New use for succinylated sugarcane bagasse containing adsorbed Cu2+ and Ni2+ : ...
Balzer, Rosana; Probst, Luiz Fernando Dias; Fajardo, Humberto Vieira; Teodoro, Filipe Simões; Gurgel, Leandro Vinícius Alves; Gil, Laurent FrédéricThis study describes the use of succinylated twice-mercerized sugarcane bagasse containing adsorbed Cu2+ or Ni2+ ions from spiked aqueous solutions (2MSBA-Cu and 2MSBA-Ni) as heterogeneous catalysts for the catalytic oxidation of n-hexane and n-heptane in gas phase. To the best of our knowledge, this is the first study in which a spent adsorbent material based on lignocellulose biomass is used in the catalytic ...
Low temperature liquid phase catalytic oxidation of aniline promoted by niobium...
Ventura, Wellington Martins; Batalha, Daniel Carreira; Fajardo, Humberto Vieira; Taylor, Jason Guy; Marins, Natália Hadler; Noremberg, Bruno S.A microwave-assisted hydrothermal method was employed to synthesis Nb2O5 (niobium pentoxide) nanoparticles and the effects of synthesis conditions on the physical-chemical properties were evaluated. The catalytic activity of the prepared samples in the liquid phase oxidation of aniline with aqueous hydrogen peroxide as oxidizing agent was also studied. The nanoparticles showed hexagonal structure and rounded sh...
Preparation, characterization and catalytic application of Barium molybdate (Ba...
Alencar, Lorena Dariane da Silva; Mesquita, Alexandre; Feitosa, Carlos Alberto Carneiro; Balzer, Rosana; Probst, Luiz Fernando DiasBarium molybdate and Barium tungstate are important materials due their photoluminescent properties and they also have catalysis and photocatalysis applications. In this work, powders of these compounds were prepared by microwave-assisted hydrothermal (MAH) method and polymeric precursor method (PPM) and their structural and optical properties were studied. Furthermore, these materials were employed as solid ca...
Efficient ceria – silica catalysts for BTX oxidation : probing the catalytic pe...
Silva, Anderson Gabriel Marques da; Fajardo, Humberto Vieira; Balzer, Rosana; Probst, Luiz Fernando Dias; Prado, Nayara Teodoro doThis paper describes a systematic investigation on the synthesis of CeO2 supported on SiO2 by two different methods: (i) the in situ incorporation of CeO2 onto MCM-41 and (ii) wet impregnation. We were interested in investigating how the CeO2 preparation could influence their physicochemical properties and catalytic performances towards the benzene, toluene, and o-xylene (BTX) oxidation reactions. Our results s...
Use of Al2O3 in an automated on-line pre-concentration system for determination...
Souza, Érica Silva; Martins, Amarildo Otavio; Fajardo, Humberto Vieira; Probst, Luiz Fernando Dias; Carasek, EduardoThis paper presents the development of an on-line pre-concentration system to determine cadmium(II) in aqueous samples. The analyte was trapped in a mini-column filled with Al2O3 in the form of macro-spheres obtained by the mixture of Al(NO3)3•9H2Oaq and chitosan dissolved in acetic acid. The mixture was dropped into an NH4OH aqueous solution under rigorous agitation using a peristaltic pump, the macro-spheres ...
Ce1−xSmxO1.9−δ nanoparticles obtained by microwave assisted hydrothermal proces...
Silva, Anderson Gabriel Marques da; Rodrigues, Thenner Silva; Dias, Anderson; Fajardo, Humberto Vieira; Gonçalves, Rosana de FátimaHeterogeneous catalysts based on Sm-doped ceria were employed for the first time in the liquid-phase oxidation of α-bisabolol. Nanometer-sized catalysts were obtained by microwave-hydrothermal synthesis and were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR), Raman spectroscopy and N2-physisorption. The influence of Sm doping, temperature and the solvent used on the catalytic b...
Magnesium oxide prepared via metal–chitosan complexation method : application a...
Almerindo, Gizelle Inácio; Probst, Luiz Fernando Dias; Campos, Carlos Eduardo Maduro de; Almeida, Rusiene Monteiro deA simple method to prepare magnesium oxide catalysts for biodiesel production by transesterification reaction of soybean oil with ethanol is proposed. The method was developed using a metal–chitosan complex. Compared to the commercial oxide, the proposed catalysts displayed higher surface area and basicity values, leading to higher yield in terms of fatty acid ethyl esters (biodiesel). The deactivation of the c...
Synthesis of titania/carbon nanocomposites by polymeric precursor method.
Carreño, Neftalí Lenin Villarreal; Garcia, Irene Teresinha Santos; Carreño, Leidne S. S. M.; Nunes, Michael Ramos; Leite, Edson RobertoHere we describe a single chemical route to obtain highly dispersed nanometric Ni particles embedded in titania/carbon matrixes (amorphous and crystalline). The synthesis of these nanocomposites is based on a polymeric precursor method. The metallic Ni nanoparticles (1–15 nm) were obtained in a single process. We also present the results of photocatalytic experiments involving a series of nanocrystalline compos...