Physicochemical properties of nanostructured Pd/lanthanide-doped ceria spheres with high catalytic activity for CH4 combustion
| Autor: | Juan J. Delgado-Jaén, L. M. Acuña, Richard T. Baker, R. O. Fuentes, A. Gabriela Leyva, Huiyan Pan, Xiaowei Chen |
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| Přispěvatelé: | University of St Andrews. School of Chemistry, University of St Andrews. St Andrews Sustainability Institute, University of St Andrews. EaSTCHEM |
| Rok vydání: | 2018 |
| Předmět: |
Lanthanide
Materials science NDAS Analytical chemistry CATALYSTS INGENIERÍAS Y TECNOLOGÍAS 02 engineering and technology 010402 general chemistry 01 natural sciences Oxidation state Ingeniería de los Materiales Oxidizing agent QD General Materials Science R2C Incipient wetness impregnation NANOMATERIALS CERIA Aqueous solution Renewable Energy Sustainability and the Environment General Chemistry QD Chemistry 021001 nanoscience & nanotechnology XANES Nanomaterial-based catalyst 0104 chemical sciences purl.org/becyt/ford/2 [https] Crystallite BDC purl.org/becyt/ford/2.5 [https] 0210 nano-technology |
| Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| ISSN: | 2050-7496 2050-7488 |
| DOI: | 10.1039/c8ta00203g |
| Popis: | In this work, nanostructured Ce0.9Gd0.1O2-δ (GDC) and Ce0.9Pr0.1O2-δ (PrDC) spheres previously obtained by microwave assisted hydrothermal homogeneous co-precipitation were impregnated with 1 wt% Pd by the incipient wetness impregnation by an aqueous Pd2+ solution. Their properties were characterized by synchrotron radiation X-ray diffraction (SR-XRD), X-ray absorption near-edge spectroscopy (XANES) and scanning and high resolution electron microscopy with X-ray spectroscopy. Spherical particles with average diameters around 200 nm were found to consist of crystallites of average size, 10 nm, with small particles of PdO finely dispersed over the sphere surface. In situ XRD and XANES experiments were carried out under reducing and oxidizing conditions in order to investigate the redox behaviour of these materials and to evaluate the effect of Pd loading on the oxidation state of Ce. All of the lanthanide-doped ceria (LnDC) supports were found to have a cubic crystal structure (Fm3m space group). An increase in lattice parameters was observed under reducing conditions which was attributed to the reduction of Ce4+ ions to the larger Ce3+ ions, and to the associated increase in oxygen vacancy (VO) concentration. Addition of Pd to the LnDC spheres increased their Ce3+ content. Finally, catalytic tests for CH4 combustion were performed on the LnDC and Pd/LnDC nanocatalysts. The best performance was observed in samples with 1 wt% Pd loading, which exhibited T50 values (temperature at which 50% of CH4 conversion was reached) close to 310 °C. These values are 220 °C and 260 °C lower than those obtained for nanostructured PrDC and GDC spheres alone, respectively. Fil: Fuentes, Rodolfo Oscar. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Acuña, Leandro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina Fil: Leyva, A. Gabriela. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina Fil: Baker, Richard T.. University of St. Andrews; Reino Unido Fil: Pan, Huiyan. Universidad de Cádiz; España Fil: Chen, Xiaowei. Universidad de Cádiz; España Fil: Delgado Jaén, Juan J.. Universidad de Cádiz; España |
| Databáze: | OpenAIRE |
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