Conversion of isopropylbenzene over AlSBA-15 nanostructured materials

In this paper we studied the application of a series of AlSBA-15 catalysts with different Si/Al ratios on the reaction of conversion of isopropylbenzene. The catalysts were synthesized via hydrothermal method and characterized by nitrogen adsorption at 77 K and Small Angle X-ray Scattering (SAXS). Catalytic tests were accomplished in a continuous flow fixed bed microreactor. The obtained results showed catalytic activity for all AlSBA-15 catalysts producing benzene and propene as main products

Synthesis of LaNiO3 perovskite type by chelating precursor method using EDTA: optimization of chelating content

The perovskites are strategic materials due their catalytic, electronic and magnetic properties. These properties are influenced by the calcination and synthesis conditions. In this work was carried out the synthesis of LaNiO3 perovskite-type by chelating precursor method using EDTA and also was studied the optimization of the EDTA content in the synthesis. The synthesized materials were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TG) and Infrared Spectroscopy (FTIR). In the optimization of the EDTA content the lowest ratio of metal / EDTA used was 1.0 / 0.1, where it was possible to obtain monophasic perovskite

Yield of aromatics from naphthenics upon catalytic cracking

Cis- e trans decalina foram submetidas à reação com catalisadores de craqueamento, para estudar a formação de aromáticos numa fração particular de produtos líquidos do processo de craqueamento catalítico fluido (FCC). Um reator batelada em leito fluidizado, CREC, foi usado a 673 e 723 K com tempos de contato entre 3 e 15 s. Cis-decalina foi muito mais reativa. Apesar de diferenças induzidas e medidas na acessibilidade dos catalisadores, seus perfis de atividade foram similares, sugerindo que restrições difusionais não prevalecem. Os produtos foram hidrocarbonetos C1-C12, enquanto o coque foi muito baixo. Reações de isomerização, craqueamento, transferência de hidrogênio, abertura/contração de anel e alquilação ocorreram, e produtos das várias reações foram observados em tempos de reação muito baixos. Naftênicos bicíclicos C10 e aromáticos alquil-substituídos C7-C11 ou nafteno-aromáticos foram os produtos mais importantes. Um mecanismo de reação com três rotas iniciais (isomerização, abertura de anel e reações de transferência de hidrogênio) foi proposto. _________________________________________________________________________________________ ABSTRACT: Cis- and trans-decalin were reacted over cracking catalysts to study the formation of aromatics in a particular fraction of the liquid products obtained in the fluid catalytic cracking process (FCC). A batch, fluidized bed CREC riser simulator reactor was used at 673 and 723 K and contact times varied from 3 to 15 s. Cis-decalin was much more reactive. Despite differences induced and measured in their accessibility indices, the catalysts led to similar activity profiles, suggesting that diffusion restrictions do not prevail. Products were C1-C12 hydrocarbons while coke was very low. Isomerization, cracking, hydrogen transfer, ring opening, ring contraction and alkylation reactions occurred and products from the various reactions were observed at very short reaction times. Bicyclic C10 naphthenics and alkyl-substituted C7-C11 aromatics or naphtheno-aromatics were the most important products. A reaction mechanism with three initial routes (isomerization, ring opening and direct hydrogen transfer reactions) was proposed