Navegando por Autor "Rossetto, Enéderson"
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Artigo Anchoring via covalent binding of β-diimine-nickel complexes in SBA-15 and its application in catalytic reactions(Elsevier, 2015-08-05) Rossetto, Enéderson; Nicola, Bruna Pes; Souza, Roberto Fernando de; Pergher, Sibele Berenice Castellã; Gusmão, Katia BernardoThe β-diimine ligands 2-(phenyl)amine-4-(phenyl)imine-2-pentene (L1) and 2-(2,6-dimethylphenyl)amine-4-(2,6-dimethylphenyl)imine-2-pentene (L2) were anchored covalently to SBA-15. The ligands were combined with (3-chloropropyl) trimethoxysilane (CPTMS), which is a trialkoxysilane group, and anchored to a mesoporous SBA-15 support through a complexation of the silanols of the silica matrix with nickel. These complexes were synthesized as catalysts precursors for ethylene and propylene oligomerization processes. The support was first synthesized and calcined before being anchored to the ligand, generating the nickel complex. These materials were characterized using various techniques such as 13C and 29Si NMR, small angle XRD, thermogravimetric analysis, N2 adsorption, transmission electron microscopy, elemental analysis and flame atomic absorption spectroscopy. The heterogenized complexes are active and selective during ethylene and propylene oligomerization, generating C4 and C6 products and alkylation products ranging from C10–C16. The alkylation process being a parallel reaction. The Ni-β-diimine/SBA-15 (SC1) complexes showed an activity of 7.2 × 103 h−1 for the ethylene oligomerization with 98% selectivity toward α- and C4 products and an activity of 2 × 103 h−1for the propylene oligomerization with a 13% selectivity toward C6 linear products. The results of the oligomerization reactions reveal the influence of the support on the products obtainedArtigo Bentonites impregnated with TiO2 for photodegradation of methylene blue(Elsevier, 2010-05) Rossetto, Enéderson; Petkowicz, Diego Ivan; Santos, João Henrique Zimnoch dos; Pergher, Sibele Berenice Castellã; Penha, Fábio GarciaFour bentonites and one diatomite from Rio Negro (Argentina) were used as supports for titanium oxide (TiO2). The materials were characterized by X-ray diffraction, scanning electron microscopy, infrared spectroscopy, textural analysis by nitrogen adsorption, elemental analysis and diffuse reflectance spectroscopy. The specific surface areas calculated by the BET method were 76, 46, 80, and 31 for the bentonites and 153 m2/g for diatomite and were not changed by impregnation with TiO2. SEM analysis revealed agglomerates, probably due to titania domains on the surface. The properties of the lamellar materials were maintained after TiO2 impregnation, and all materials showed methylene blue photodegradation activity. The bentonites showed a higher activity than the commercial catalyst P25, likely due to the TiO2 distribution and better accessibility.Tese Complexos Níquel-β-diiminas heterogeneizados em MCM-41 e SBA-15: aplicação em oligomerização de olefinas(Universidade Federal do Rio Grande do Norte, 2015-07-31) Rossetto, Enéderson; Pergher, Sibele Berenice Castella; Gusmão, Kátia Bernardo; ; http://lattes.cnpq.br/8664708384378316; ; http://lattes.cnpq.br/5249001430287414; ; http://lattes.cnpq.br/1344299870528860; Santos, Eduardo Nicolau dos; ; http://lattes.cnpq.br/9246600674685393; Vitor Sobrinho, Eledir; ; http://lattes.cnpq.br/8488499388852606; Souza, Michele Oberson de; ; http://lattes.cnpq.br/3536832030182279; Braga, Tiago Pinheiro; ; http://lattes.cnpq.br/9170391410490804Os ligantes β-diiminas 2-(fenil)amino-4-(fenil)imino-2-penteno e o 2-(2,6-dimetilfenil)amino-4-(2,6-dimetilfenil)imino-2-penteno foram combinados com o grupo alcoxisilano cloropropiltrimetoxisilano (CPTMS) e ancorado covalentemente aos suportes mesoporosos MCM-41 e SBA-15, coordenados pela interação com os grupos silanóis da matriz das sílicas e complexados com níquel. Os complexos Ni-β-diimina/mesoporosos foram sintetizados para aplicação em reações de oligomerização do etileno e do propileno e para comparação dos resultados entre o sistema homogêneo com o sistema heterogêneo. O suporte foi primeiramente sintetizado e calcinado. Após foi realizado o ancoramento dos ligantes e posterior complexacão do níquel. Estes materiais foram caracterizados por várias técnicas, tais como: RMN de 1H, 13C e 29Si, DRX de baixo ângulo, Infra-vermelho (IR), análise termogravimétrica, análise de isotermas de adsorção-dessorção de N2, microscopia eletrônica de transmissão (MET) e de varredura (MEV), análise elementar e espectroscopia de absorção atômica para confirmar o sucesso das sínteses dos materiais. Ambos os complexos homogêneos e os heterogeneizados são ativos e seletivos para as reações de oligomerização do etileno e do propileno. Os materiais heterogeneizados foram menos ativos que os complexos análogos homogêneos nas reações de oligomerização do etileno, porém, foram mais seletivos tanto para frações C4 quanto para α-C4. Nas reações com o propileno os complexos homogêneos promoveram à reação de dimerização e os complexos heterogeneizados à reação de alquilação do tolueno com o propileno.Artigo Heterogeneous complexes of nickel MCM-41 with β-diimine ligands: applications in olefin oligomerization(Elsevier, 2015-03) Rossetto, Enéderson; Nicola, Bruna Pes; Souza, Roberto Fernando de; Bernardo-Gusmão, Katia; Pergher, Sibele Berenice CastellãThe β-diimine ligands 2-(phenyl)amine-4-(phenyl)imine-2-pentene and 2-(2,6-dimethylphenyl)amine-4-(2,6-dimethylphenyl)imine-2-pentene were combined with the alkoxysilane group chloropropyltrimethoxysilane (CPTMS) and covalently anchored to a mesoporous MCM-41 support; they were ordered via interactions with the silanols of the silica matrix and complexed with nickel. The complexes were synthesized for use in ethylene and propylene oligomerization and for comparing the results of homogeneous and heterogeneous systems. The support was first synthesized, calcined, anchored to the ligand, and then, complexed with nickel. These materials were characterized using various techniques, such as 1H, 13C, and 29Si NMR, small angle XRD, thermogravimetric analysis, adsorption isotherms, transmission electron microscopy, and flame atomic absorption spectroscopy, to confirm the success of the synthesis. Both homogeneous and heterogeneous complexes are active and selective for the reactions of ethylene and propylene oligomerization