Síntese de peneiras moleculares MCM-41 impregnadas com Co e Co/Ru utilizando fontes alternativas de sílica.

Abstract

This study aimed to synthesize and characterize the molecular sieve mesoporous MCM-41, using different sources of silica, and develop cobalt-based catalysts and ruthenium. The MCM-41 molecular sieves were synthesized using as silica source the rice husk ash, ash from sugarcane bagasse, clay chocolate B and silica Aerosil 200 with the following molar basis: 1.0 CTMABr: 4.0 SiO2: 1 Na2O: 200 H2O. The MCM-41 molecular sieves were obtained calcined in a muffle at 600 ° C for 7 hours. The deposition of metals (cobalt and ruthenium) on the supporting MCM-41 was performed by wet impregnation and then calcined. The samples obtained were characterized by spectroscopy techniques Fluorescence and X-rays by Energy Dispersive (FRX-ED), X-ray diffraction (XRD), Adsorption Nitrogen Physics, Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopic (FTIR). The results proved possible to obtain MCM-41 molecular sieve having different silica sources, the micrographs it is noted that the materials have similar morphology, consisting of spongy form agglomerates. The XRD patterns of the catalysts showed that after impregnation and calcination of the metal, there were no changes in the hexagonal structure. From the results of Physical Adsorption of N2 was observed adsorption isotherms of type IV, typical of mesoporous materials and high surface area values. The metal catalyst compositions presented in predefined proportions and after impregnation of the obtained ruthenium better dispersion of metals on the molecular sieve. The spectra showed bands in the region of 500 - 4000 cm-1, characteristic of the fundamental vibrations of the specific functional groups present in the structure of the molecular sieve MCM-41 and bands related to the structure of the cobalt oxide (Co3O4).