Supported metallic catalysts for the production of syngas by dry reforming of methane

Fil: Maina, Silvia Carolina Palmira. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina.Se estudiaron catalizadores de Ru e Ir soportados sobre gamma alúmina pura y modificada con metales alcalinos (Na y K) y alcalinotérreos (Ba, Ca y Mg) a fin de obtener materiales catalíticos con elevada actividad, selectividad y estabilidad en la reacción de reformado seco de metano para la obtención de gas de síntesis (hidrógeno + monóxido de carbono), con una mínima desactivación por deposición de carbón y una prolongada vida útil. Se determinó la superficie específica y volumen de poro de los soportes, se ensayaron en la reacción de deshidratación de 2-propanol y se caracterizaron por DRX y TPD. Los catalizadores se caracterizaron por TPR, XPS y TEM. Todas las formulaciones catalíticas fueron activas en la reacción de reformado de metano con dióxido de carbono a 750°C, previa reducción con hidrógeno a la temperatura de reacción. Las formulaciones catalíticas más promisorias fueron ensayadas durante largos tiempos de reacción (59 h) a fin de evaluar la estabilidad de la fase metálica (TPO) y se analizó el efecto del tamaño de las partículas metálicas por TEM. Por último se realizaron ensayos adicionales para estudiar el posible mecanismo de reacción, analizando el efecto del dióxido de carbono y del metano sobre los soportes y catalizadores ya que, en estos catalizadores de Ir y de Ru soportados sobre alúminas dopadas, existiría un mecanismo continuo de limpieza del carbón que se va formando por la descomposición del metano. Este mecanismo permitiría que el catalizador permanezca libre de coque durante tiempos prolongados de reacción.Ru and Ir catalysts supported on gamma alumina pure and doped with alkaline (Na and K) and alkaline earth metals (Ba, Ca and Mg) were studied in the dry reforming reaction in order to achieve high and long lasting activity, selectivity and stability for the production of syngas (hydrogen + carbon monoxide) with low carbon deposition that causes deactivation. The specific surface, pore volume and acid characteristics (by 2-propanol dehydration) of the supports were measured, they also being characterized by TPD and XRD. The catalysts were characterized by TPR, XPS and TEM. All the samples were shown to be active in the dry reforming reaction at 750°C after reduced with hydrogen at the same temperature. The best samples were tested at long reaction times (59 h) to analyze the stability of the metallic phase by TPO. The metallic particle size was determined by TEM. Finally the reaction mechanism was studied by analyzing the effect of carbon dioxide and methane over the supports and catalysts since there would be a continuous elimination of the carbon deposited by methane decomposition. In this way the catalyst would stay coke free during long reaction times.Universidad Nacional del Litora

Estudio de Catalizadores de Rutenio para la obtención de Gas de Síntesis a partir del Reformado Seco de Metano

This work studies the catalytic performance in dry reforming of Ru catalysts supported on γ-Al2O3 promoted with Na, K, Mg, Ca and Ba. The supports and the catalysts were characterized and tested in the reaction of CH4 reforming with CO2. Ru/Al2O3-Na and Ru/Al2O3-K catalysts showed higher conversions and better H2/CO molar ratios. This catalytic behavior would be related with the higher metallic dispersions and with the basicity of the support. When the reduction time in H2 was shortened, a decrease of the conversions for all the catalysts, except for Ru/Al2O3-Na, was observed. This phenomenon would not be due to the thermal effect but to the reduction time.Fil: Maina, Silvia Carolina Palmira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: de Miguel, Sergio Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Scelza, Osvaldo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Jablonski, Estanislao Lorenzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Performance of Modified Alumina-Supported Ruthenium Catalysts in the Reforming of Methane with CO₂

Ruthenium (1 wt%) catalysts supported on alumina doped with alkaline (Na and K) and alkaline earth metals (Ba, Ca, and Mg) of different concentrations (1, 5, and 10 wt%) were tested in the dry reforming of methane. All catalysts were prepared by the successive impregnation method. Supports were characterized by X-ray diffraction, BET surface area, temperature-programmed desorption of CO2, and 2-propanol dehydration. Additionally, catalysts were characterized by temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Stability tests to study coke deposition were performed using long-time dry reforming reactions. All the catalysts showed good catalytic activity, and activity falls were never detected. Ru metallic phase seemed to be resistant to coke formation even though its particles are sintered during a long-term reaction

Study of the performance and stability in the dry reforming of methane of doped alumina supported iridium catalysts

Iridium catalysts supported on alumina doped with both alkaline (Na and K) and alkaline earth metals (Ba, Ca and Mg) of different concentrations (1, 5 and 10 wt%) were tested in the dry reforming of methane. Supports were characterized by X-ray diffraction, BET surface area, temperature-programmed desorption of CO2 and 2-propanol dehydration. Catalysts were characterized by temperature-programmed reduction, TEM, XPS, cyclohexane dehydrogenation and cyclopentane hydrogenolysis. Dopants were showed to suppress the acidity of the support and the γ-Al2O3 phase remained in the supports doped with Ca, Ba, Na and K after calcination at 800 °C, whereas a phase transition to magnesium aluminate was found for magnesium doped alumina. Stability tests, using long time dry reforming reactions, showed that iridium catalysts have high sintering resistance, their metallic phases being very stable since neither carbon deposition nor sinterization processes were observed.Fil: Maina, Silvia Carolina Palmira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Ballarini, Adriana Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Vilella, Irene María Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: de Miguel, Sergio Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Citral condensation with acetone on Na-MgO and Li-MgO catalysts

The effect of the Na and Li addition to MgO on the pseudo-ionone production from citral and acetone condensation in liquid phase is reported. The Na addition improves the yield to pseudo-ionone (defined as mol of produced pseudo-ionone/mol of converted citral), reaching a value of 100%, while the Li addition has a poor effect. These results can be related to the different distribution of basic sites. It was found that the catalytic activity depends on the acetone/citral and the catalyst/citral ratios. Besides, a poisoning effect of the reaction products on the catalysts was observed, even though the activity of the used catalysts can be partially restored by extraction treatments.Fil: Jablonski, Estanislao Lorenzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Vilella, Irene María Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Maina, Silvia Carolina Palmira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: de Miguel, Sergio Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Scelza, Osvaldo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Influence of Pt addition to Ni catalysts on the catalytic performance for long term dry reforming of methane

The influence of Pt addition (in very low concentrations) to a Ni/(10%)/Al 2O 3 catalyst in its catalytic performance during long-term experiments of dry reforming of methane was studied. The monometallic Pt(0.5%)/Al 2O 3 catalyst displayed a pronounced deactivation during 6500 min reaction time, mainly due to a significant sintering of the metallic phase, whereas the monometallic Ni(10%)/Al 2O 3 catalyst showed a high and stable activity along the reaction time. Compared with the Ni(10%)/Al 2O 3 catalyst, the bimetallic Ni(10%)Pt(0.5%)/Al 2O 3 sample showed a higher, and stable catalytic activity during the 6500 min reaction time and a markedly lower carbon deposition. TEM images reveal much less carbon formation and filament grow and this leads to expect a higher stability in long term processes. Characterization techniques indicate that nickel and platinum are in close contact during the simultaneous reduction of the two oxide precursors and that geometric effects (dilution and blocking) are mainly responsible for the excellent catalytic behaviour of the bimetallic NiPt catalyst.Fil: de Miguel, Sergio Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Vilella, Irene María Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Maina, Silvia Carolina Palmira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: San José-Alonso, D.. Universidad de Alicante; EspañaFil: Román-Martínez, M.C.. Universidad de Alicante; EspañaFil: Illán-Gómez, M.J.. Universidad de Alicante; Españ