SÍNTESE E CARACTERIZAÇÃO DE CATALISADORES HETEROGÊNEOS TIPO PEROVSKITA PARA CONVERSÃO DE ÓXIDO DE NITROGÊNIO E MONÓXIDO DE CARBONO EM GASES DE COMBUSTÃO DE DIESEL

Abstract

This study aims to prepare, characterize and study materials type perovskite (Ba3BB‟2O9 and Ba2BB‟O6) as catalysts for the reaction of NOX and CO conversion, seeking other alternatives for catalytic converters. The compounds were prepared using a polymeric precursor method, calcined at 500, 700 and 900 ° C in the period of two hours. Characterized by X-ray diffraction, infrared by transformed of Fourier, Raman and Microscopy electronic of scanning spectroscopy. According to DRX, the method favors the formation of perovskite phases treated at 400 °, 500 °, 700 ° and 900 ° C, obtaining the desired compounds in the presence of the secondary phase. In the analysis of infrared spectroscopy, verified the presence of a characteristic vibrational, that to correspond the connection between the metal-oxygen, which becomes more intense when occurs the increase in the heat treatment. This behavior has been confirmed by the stretching associated with internal vibration of the oxygen of the octahedron in 360 cm-1 and 410 cm-1 of the A1g(O) e 2Eg(O) observed in the sample belonging to the order of 1:2. For catalytic activity toward conversion reaction of the gases mentioned, were more active for CO, highlighting the perovskite Ba3CaNb2O9 where the conversion was directly proportional to the formation of the structure of the compound and the reduction of the presence of secondary phase.