Decomposition of N(2)0 (de-N(2)0) is a simple and economical way to reduce emissions of this greenhouse gas in industrial processes. In this work, LaCo0(3), LaFe05Co05O3 and LaFe0(3) catalysts were prepared, characterized by XRD, SEM/DES and TPR-H2 and evaluated in de-N(2)0 in the presence of 0(2) and H(2)0. The results showed the formation of perovskite structures with orthorhombic and rhombohedral symmetry, irregular morphology and also cobalt and ¡ron oxides. Reduction of cobalt species occurs at temperatures between 300-800 °C and only the iron oxide species are reduced below 600 °c. The order of activity in de-N(2)0 was LaCo0(3)> LaFe05Co05O3 > LaFe0(3). The catalysts LaFe0(3) and LaFe05Co05O3 showed deactivation in the presence of 0(2) and H(2)0. On the other hand, the catalyst LaCo0(3) was slightly affected with the addition of 0(2) and H(2)0 and, kept the conversión above 60%.

La descomposición de N(2)0 (de-N(2)0) es la ruta simple y económica para reducir las emisiones de este gas de efecto invernadero en procesos industriales. En este trabajo catalizadores LaCo0(3), LaFe05Co05O3 y LaFe0(3) fueron preparados, caracterizados por DRX, MEV/EDS y RTP-H2 y evaluados en la de-N(2)0 en presencia de 0(2) y H(2)0. Los resultados mostraron la formación de estructuras perovskita con simetría ortorrómbica y romboédrica, morfología irregular y también óxidos de cobalto y hierro. La reducción de las especies de cobalto ocurre a temperaturas entre 300-800 °C y, solamente las especies de óxido de hierro se reducen por debajo de 600 °c. La orden de actividad en de-N(2)0 fue LaCo0(3)> LaFe05Co05O3 > LaFe0(3). Los catalizadores LaFe0(3) y LaFe05Co05O3 mostraron desactivación en presencia de 0(2) y H(2)0. Por otro lado, el catalizador LaCo0(3) fue poco afectado con la adición de 0(2) y H(2)0 y mantuvo la conversión por encima del 60%.

Cobalt or iron oxides supported or not on zeolite Hbeta were prepared and evaluated in the reduction reaction of NO by CO in presence of O2, SO2 or H2O. XRD results evidenced the Hbeta structure and the formation of Co3O4 and Fe2O3. TPR-H2 analysis showed complete reduction of cobalt oxide at lower temperatures than for iron oxide. The catalysts are quite active and the activity depends on the reaction temperature. The highest conversions rates were observed for pure iron oxide, which can be a relatively low cost catalyst for reduction of NO by CO, with high selectivity towards the N2 formation.

The development of cobalt catalysts to produce hydrogen from ethanol is the goal of this investigation. Co/Al2O3 catalysts were prepared by impregnation and characterized by atomic absorption, nitrogen adsorption, X-ray diffraction, Raman spectroscopy, temperature programmed reduction and carbon analysis. The catalysts contained Co3O4 oxide and Co3+ and Co2+ species interacting with alumina. The cobalt load affects the crystal size and the crystalline structure and higher Co loads influence the reaction mechanism, changing the selectivity of the catalysts, decreasing the amount of CO produced and avoiding the formation of products catalyzed by the support. The ethanol conversion was 50-70% with 10-<1% of CO in the hydrogen.