Synthesis, characterization and catalytic application of cerium-modified MCM-41

The nanostructured CeMCM-41 material was synthesized by the hydrothermal method, using cethyltrimethylammonium bromide as template. The sample was characterized by X-ray diffraction, energy-disperse X-ray, thermogravimetry, nitrogen adsorption isotherm and pore size distribution. The specific surface area of CeMCM-41 was equivalent to 850 m(2) g(-1), with the pore width and mesopore volume of 3.8 nm and 0.8 cm(3) g(-1), respectively. To evaluate the catalytic performance of the CeMCM-41, a mass of ca. 0.1 g was heated from room temperature up to 723 K at heating hate of 10degreesC min(-1) using oxygen flowing at 50 ml min(-1). The CeMCM-41 was tested as catalyst for n-heptane oxidation, in a fixed-bed continuous-flow reactor, at 723 K and F/W ratio (molar flow of reactant per mass of catalyst) of 0.4-0.6 g h mol(-1). The obtained products were analyzed in a gas chromatograph coupled to a mass spectrometer. The GGMS analysis revealed that the main oxidation products obtained were typically CO and CO2, with 12% of hydrocarbon conversion. (C) 2003 Published by Elsevier Science (USA).