Preparation of Pt catalysts supported on activated carbon felts (ACF)

Activated carbon felts (ACFs) have been used as supports for Pt catalysts. The preparation was carried out by the impregnation method using chloroplatinic acid as metal precursor. The effect of impregnation time and surface chemistry of the support on the catalytic properties and the characteristics of the metallic phase have been investigated. Nitrobenzene (Nbz) hydrogenation in liquid phase at 25 °C and cyclohexane (CH) dehydrogenation in gas phase at 300 °C were used as catalytic tests. The state of platinum in reduced catalysts (at 100 and 350 °C) was studied by TPR and XPS. Oxygen surface groups only produce a slight effect on the catalytic properties. The use of low impregnation times (30 min) during the preparation of Pt/ACF leads to catalysts with Pt mainly deposited in the outer shell of the fibers, while at higher impregnation times, the metallic atoms seem to be deposited inside the pores. Pt(0) species appear in catalysts reduced at 100 °C by effect of the reducing properties of the carbon fiber exhibiting a considerable catalytic activity for Nbz hydrogenation.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 ; 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 ; ArgentinaFil: Jablonski, Estanislao Lorenzo. 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: Salinas Martinez de Lecea, C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Linares Solano, A.. Universidad de Alicante; Españ

Study of the performance of Pt catalysts supported on activated carbon felt and granular carbon for nitrobenzene hydrogenation

The catalytic behavior of the Pt (1 wt%) catalysts supported on purified activated carbon felt (ACF) and powder carbon (C) has been studied in the nitrobenzene (NBZ) hydrogenation reaction in liquid phase after activation under a H2 atmosphere between 298 and 623 K. Hydrogen chemisorption measurements, temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the metallic phase of the catalysts. For Pt/ACF catalysts, the catalytic activity in nitrobenzene hydrogenation after reduction at 298 K was very high and it decreased as the reduction temperature increased up to 373 K. On the other hand, the Pt/C catalyst after reduction at 298 K was inactive. The activity of the Pt/C catalysts increased in a moderate way when the reduction temperature increases up to 373 K. Between 373 and 623 K of reduction temperature, the hydrogenation rate was modified in a minor proportion for both catalysts. The Pt/ACF catalyst previously reduced at 298 K showed a lag step before the reaction ignition. This effect could be attributed to the tendency the metallic centers have to conform the proper arrangement to hydrogenate the nitrobenzene molecule.Fil: 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"; 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

Pt, PtSn and PtGe catalysts supported on granular carbon for fine chemistry hydrogenation reactions

Two series of PtSn and PtGe catalysts with different metallic loadings, supported on activated carbon powder, were prepared by successive impregnation. Both the effects of the second metal addition and the Sn or Ge loading on the activity and selectivity in the carvone and the citral hydrogenations (used as catalytic tests) were investigated. In all cases the support was purified to eliminate undesirable elements such as sulfur and, for high Pt loadings, carbon was functionalized with nitric acid so as to introduce more oxygen-containing groups. The carvone hydrogenation was carried out with PtSn catalysts, the Pt and Sn loadings being very low. The citral hydrogenation was carried out with PtSn and PtGe catalysts with higher metal loadings supported on both purified, and purified and functionalized carbons. Besides, the effect of the branched solvent in the activity and selectivity of the citral hydrogenation reaction was also studied with PtSn catalysts. The catalysts were characterized by temperature-programmed reaction (TPR), test reactions of the metallic phase (cyclohexane dehydrogenation and cyclopentane hydrogenolysis), hydrogen chemisorption and by X-ray photoelectron spectroscopy (XPS). The catalytic activity in the carvone hydrogenation showed a maximum for the monometallic catalyst with respect to the Sn loading. For the catalyst with the highest tin loading (0.4 wt%) even though the activity drastically decreased, the selectivity to the doubled unsaturated alcohol (carveol) was very important. Although the citral hydrogenation gave very good results with PtSn systems with high metallic loadings, the opposite happened with the PtGe ones. Moreover, the more branched solvents modified the selectivity to unsaturated alcohols of the PtSn catalyst in the citral hydrogenation.Fil: 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"; 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

Synthesis of PtSn nanoparticles on carbon materials by different preparation methods for selective catalytic hydrogenation of citral

In this work, PtSn bimetallic catalysts supported on three different carbons were prepared by two methods: a) conventional impregnation followed by a reduction treatment under H2-flow (CI) and b) deposition-reduction in liquid phase (RLP). All the catalysts were tested in the selective hydrogenation of citral to the unsaturated alcohols (UA). A strong influence of the preparation method and the support was found over the selectivity to UA. For CI prepared catalysts, low Sn loadings give a metallic phase with highly ordered PtSn alloys, while for RLP catalysts, high Sn loadings give highly ordered phases with Sn ionic species intercalated in the Pt metallic phase. Both ordered phases are highly effective to promote the hydrogenation of carbonyl group. For the RLP method, high Sn/Pt molar ratios in solution leads to the formation of PtSn complexes with a good interaction between metals.Fil: Stassi, Julieta Paola. 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: Méndez, Jonathan. 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"; ArgentinaFil: Zgolicz, Patricia 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"; Argentin

Bimetallic catalysts supported on novel spherical MgAl2O4-coated supports for dehydrogenation processes

Novel Pt and PtSn catalysts were developed from structured supports of α-Al2O3 spheres coated with MgAl2O4 by two methods: advanced Bohemite-nitrate with purification (BNAP) and citrate-nitrate with two layers (CN2). Both structured supports showed a thin porous layer of MgAl2O4 with a high specific surface area of around 130 m2 g−1. A stable and uniform MgAl2O4 layer on the spherical nuclei was achieved by both synthesized coating methods. Therefore, a good interaction with the metals which leads to high metallic dispersions was obtained. These catalysts were used in the production of butenes by n-butane dehydrogenation reaction. The bimetallic catalysts showed both high values of n-butane conversion (25–30 %) and selectivity to butenes (89–95 %). The PtSn catalyst supported on spheres coated by CN2 method displayed high values of yield to butenes (about 30%), which are higher than those of a catalyst used in the industry.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: Zgolicz, Patricia 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: Bocanegra, Sonia Alejandra. 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

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

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

Characterization and catalytic performance of PtSn catalysts supported on Al2O3 and Na-doped Al2O3 in n-butane dehydrogenation

PtSn/Al2O3 and PtSn/Al2O3-Na catalysts display important modifications of the metallic phase with respect to Pt/Al2O3 one. In this sense, TPR and XPS results show the presence of strong interactions between Pt and Sn, with probable alloy formation, which would be responsible for the decrease of the reaction rate and the increase of the activation energy in cyclohexane dehydrogenation. Besides the experiments of cyclopentane hydrogenolysis show that the alkali metal addition to bimetallic PtSn/Al2O3 catalysts completely eliminates the hydrogenolytic ensembles, which could be due to a geometric modification of the metallic phase. These important modifications in the nature of the metallic function due to the simultaneous addition of Na and Sn to Pt/Al2O3 are responsible for the excellent catalytic performance in the n-butane dehydrogenation, thus giving high conversions, selectivities to butenes higher than 95%, and lower deactivation capacity than those corresponding to bimetallic PtSn catalysts (with different Sn contents) supported on undoped alumina. The excellent stability of PtSn/Al 2O3-Na catalysts would be due to a low carbon formation during the reaction, such as it was observed from pulse experiments.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: Bocanegra, Sonia Alejandra. 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: Ruiz Guerrero, Ana María. Universidad Nacional de Educación a Distancia; EspañaFil: 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

Differences and similarities of supported Ge-Pt/C catalysts prepared by conventional impregnation and controlled surface reactions

Two methods of modification of monometallic platinum catalyst supported on functionalized active carbon were used for the preparation of Ge-Pt/C bimetallic catalysts: (i) conventional impregnation (CI) and (ii) controlled surface reactions (CSRs). All results, namely the study of germanium anchoring reaction, two test reactions (cyclohexane dehydrogenation and cyclopentane hydrogenolysis), H2 and CO chemisorption, indicate that the modification of Pt with Ge using CSRs was highly selective, i.e., almost 100% of Ge introduced was anchored to platinum. On the other hand results showed that in catalysts prepared by CI method Ge was located mainly on the support.Fil: Borbáth, Irina. No especifíca;Fil: Somodi, Ferenc. No especifíca;Fil: 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"; 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"; ArgentinaFil: Margitfalvi, József L.. No especifíca

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