Artículo
Pd–Cu interaction in Pd/Cu-MCM-41 catalysts: Effect of silica source and metal content
Benito, Patricia Virginia
; Gregori, Manuel; Andreoli, Sara; Fornasari, Giuseppe; Ospitali, Francesca; Millefanti, Stefano; Avila, Maria Sol
; Garetto, Teresita Francisca
; Albonetti, Stefania
Fecha de publicación:
09/2014
Editorial:
Elsevier
Revista:
Catalysis Today
ISSN:
0920-5861
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Pd/Cu-MCM-41 catalysts for the hydrodechlorination of CF3OCFClCF2Cl to CF3OCFCF2 were prepared. Palladium- and copper-containing samples (Pd/Cu = 1 molar ratio) were synthesized by adding Pd2+ and Cu2+ during the formation of MCM-41, and then the slurries were aged by microwave-hydrothermal treatment. The effect of the silica source (silicates or TEOS) and total metal loading (2.4 and 4.0 wt.%) on the chemical–physical properties and catalytic performances was studied. Bimetallic silicate-derived samples show features similar to those of the pristine MCM-41, regardless of the total metal content. Conversely, the long-range order of the mesoporous structure decreases for TEOS-derived catalysts, and large metal contents seem to alter the structure for these materials. During template removal by thermal treatment, palladium and copper are on the surface of MCM-41 particles, forming Pd1−xCuxO solid solutions whose composition is silica source-dependent. The amount of copper in Pd1−xCuxO is greater for TEOS-derived samples. After reduction, both Pd- and Cu-enriched alloys were found by XRD in silicate-derived samples, while XPS measurements indicated that the surface of the catalyst is enriched with copper. XRD and XPS analyses on TEOS samples indicated that the surface Cu/Pd ratio is closer to 1, and fcc PdCu alloys with a high copper content were identified. The composition of metallic particles modifies the selectivity, TEOS-derived catalysts being more selective to the target CF3OCFCF2.
Palabras clave:
Palladium
,
Copper
,
Mcm-41
,
Silicate
,
Teos
,
Hydrodechlorination
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Articulos(INCAPE)
Articulos de INST.DE INVEST.EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Articulos de INST.DE INVEST.EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Citación
Albonetti, Stefania; Garetto, Teresita Francisca; Avila, Maria Sol; Millefanti, Stefano; Ospitali, Francesca; Fornasari, Giuseppe; et al.; Pd–Cu interaction in Pd/Cu-MCM-41 catalysts: Effect of silica source and metal content; Elsevier; Catalysis Today; 246; 9-2014; 108-115
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