Sínteses e caracterizações de materiais microporosos com estrutura cristalográfica mista e suas aplicações como catalisadores em reações de conversão de biomassa em produtos de química fina

• Ano de defesa: 2015
• Autor(a) principal: Paula, Alex Silva [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Biologia molecular; Biofísica; Biomassa; Catalisadores; Quimica fina; Molecular biology
• Link de acesso: http://hdl.handle.net/11449/138430

New synthetic routes based on sol-gel chemistry were developed in order to synthesize new octahedral-tetrahedral microporous materials containing transition metals in their framework. Metal transitions such as zirconium, vanadium and germanium were explored for this purpose together with organic templates molecules derivatives of cis-2,6-dimethylpiperidine, cis and trans-3,5-dimethylpiperidine and (S)-Spartenium. The starting point of this study was the syntheses of the organic molecules through nucleophílic substitution and cyclization reactions. The as made organic molecules were systematically recrystallized by different mixture of solvents and then characterized by 13C and 1H NMR. Afterwards the characterization the organic molecules were used as structure directing agents for the syntheses of octahedral-tetrahedral metallosilicates. The metallosilicates containing zirconium, vanadium and germanium were characterized by x-ray diffraction, scanning electronic microscopy, solid state nuclear magnetic resonance of 29Si, 51V, 19F and 13C, thermogravimetric analysis, Infra red spectroscopy, UV-Vis by diffuse reflectance and Raman scattering. The acid sites of the metallosilicates were measured by chemisorptions of ammonium and pyridine and the process was followed by Infra red spectroscopy. Afterwards the physicochemical characterization the metallosilicates were used as heterogeneous catalysts for the conversion of glycerol into fine chemicals via oxidehydration reactions. The vanadosilicate prepared in presence of structure directing agent containing the mixture of (3R,4S) 1,1,3,5-tetramethylpiperidine and (3S,4S) 1,1,3,5-tetramethylpiperidine presented the best results regarding the glycerol conversion into fine chemicals. The conversion rate of glycerol was around of 96% and the acrylic acid 24 selectivity rate is around of 89%. Besides acrylic acid chemicals such as acrolein ...