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61.
R. P��rez-Hern��ndez A. D. Avenda?o E. Rubio V. Rodr��guez-Lugo 《Topics in Catalysis》2011,54(8-9):572-578
Pd/ZrO2?CTiO2 catalysts were synthesized by sol?Cgel method and studied on the steam reforming of methanol reaction for hydrogen production. X-ray diffraction patterns of the Pd supported on single oxides showed crystalline structures associated with the zirconia or titania respectively. However, the XRD pattern of the mixed ZrO2?CTiO2 oxide showed broad diffraction pattern consistent with an amorphous material. The reducibility of the PdO supported on single and mixed oxides showed a negative peak associated with the desorption of H2 due to the decomposition of Pd-hydride (PdH); as well as, positive peaks related with the hydrogen consumption on the reduction of the PdO supported. Catalytic activity on the palladium supported on the mixed ZrO2?CTiO2 oxide showed higher catalytic activity than the Pd supported on the single TiO2 or ZrO2 oxides. This finding was associated at the higher Pd species present in the Pd/ZrO2?CTiO2 than on the Pd/ZrO2 or Pd/TiO2 catalysts how was observed by TPR. 相似文献
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Gy. P?lczmann J. Valyon ��. Szegedi R. M. Mih��lyi J. Hancs��k 《Topics in Catalysis》2011,54(16-18):1079-1083
A Pt/AlSBA-15 catalyst was investigated in the selective isomerisation of Fischer?CTropsch wax, which type of catalyst have not been studied in detail in this reaction system yet. Its hydroconversion activity was compared with that of the Pt/SAPO-11 catalyst. Based on the results it was concluded that the selective isomerization of the Fischer?CTropsch wax can be a new application of the Pt/AlSBA-15 catalyst. 相似文献
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Carlos Plana Sabino Armenise Antonio Monz��n Enrique Garc��a-Bordej�� 《Topics in Catalysis》2011,54(13-15):914-921
A catalyst of Ni supported on alumina coated monolith has been prepared, characterized and tested in NH3 decomposition. The characterization of the catalyst by XPS and TPR showed that there is no formation of aluminates after catalyst use. It is studied the effect of the space velocity, by varying the feed flow rate and the catalyst??s length. Some evidences are shown about the reaction inhibition by produced H2 and about the reasons for the better performance of the monolith than packed bed catalyst. 相似文献
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Different types of enzymes such as lipases, several phosphatases, dehydrogenases, oxidases, amylases and others are well suited for the reactions in SC-CO2. The stability and the activity of enzymes exposed to carbon dioxide under high pressure depend on enzyme species, water content in the solution and on the pressure and temperature of the reaction system. The three-dimensional structure of enzymes may be significantly altered under extreme conditions, causing their denaturation and consequent loss of activity. If the conditions are less adverse, the protein structure may be largely retained. Minor structural changes may induce an alternative active protein state with altered enzyme activity, specificity and stability. 相似文献
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E. Ram��rez-Meneses V. Montiel-Palma V. H. Ch��vez-Herrera J. Reyes-Gasga 《Journal of Materials Science》2011,46(10):3597-3603
Carbon nanotubes (CNTs) are nanomaterials of high interest due to their unique structural, electrical, and mechanical properties. Carbon materials have been widely employed to support metallic nanoparticles for catalysis and electrochemical applications. In this work, we investigated the synthesis of platinum nanoparticles generated from the complex Pt2(dba)3 (tris(dibenzylideneacetone) diplatinum) and stabilized with a long alkyl chain amine, hexadecylamine (HDA) and supported on functionalized single-walled carbon nanotubes (SWCNTs). High resolution transmission electron microscopy (HRTEM) studies revealed isolated Pt nanoparticles (2?C3 nm) on SWCNTs. Powder X-ray diffraction (XRD) was used to assess the structure of Pt nanoparticles dispersed on SWCNTs assigned to Pt face-centered cubic (fcc). Additionally, infrared Fourier transform spectroscopy confirmed the presence of the stabilizer at the surface of the Pt nanoparticles even after the purification step and functional groups at the surface of pre-treated SWCNTs. This synthetic method may be an alternative route to prepare small size Pt nanoparticles supported on functionalized SWCNTs. 相似文献