Documents disponibles écrits par cet auteur

Promoter-induced morphological changes of Ag catalysts for ethylene epoxidation / Joseph C. Dellamorte in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 5943–5953 Titre : Promoter-induced morphological changes of Ag catalysts for ethylene epoxidation Type de document : texte imprimé Auteurs : Joseph C. Dellamorte, Auteur ; Jochen Lauterbach, Auteur ; Mark A. Barteau, Auteur Année de publication : 2009 Article en page(s) : pp. 5943–5953 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ag  catalysts  Scanning  electron  microscopy  analysis  High-throughput  reactor  experiments Résumé : The combination of high-throughput reactor experiments and scanning electron microscopy analysis of promoted Ag catalysts provides critical insights into mechanistic and morphological changes. In particular, catalysts promoted with Cu, Cd, Au, Pt, and Re were analyzed to understand the morphological effects of these promoters on the Ag particles. Cu increases the sintering of Ag particles, while Cd and Re were found to alter the Ag particle sizes into a trimodal distribution. However, contrasting effects of Re and Cd were found on the catalyst activity. Cd−Ag catalysts exhibited a 5-fold increase in the ethylene conversion for a variety of Cd loadings, compared to unpromoted Ag. Moderate increases in conversion and selectivity were seen with the addition of 25 ppm Re, while further Re impregnation led to decreases in ethylene conversion and ethylene oxide selectivity. Au and Pt block surface Ag sites by nucleating as separate particles on the silver surface. In doing so, they reduce the activity of the catalyst, but also reduce the sintering of the Ag particles. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801627k [article] Promoter-induced morphological changes of Ag catalysts for ethylene epoxidation [texte imprimé] / Joseph C. Dellamorte, Auteur ; Jochen Lauterbach, Auteur ; Mark A. Barteau, Auteur . - 2009 . - pp. 5943–5953. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 5943–5953 Mots-clés : Ag  catalysts  Scanning  electron  microscopy  analysis  High-throughput  reactor  experiments Résumé : The combination of high-throughput reactor experiments and scanning electron microscopy analysis of promoted Ag catalysts provides critical insights into mechanistic and morphological changes. In particular, catalysts promoted with Cu, Cd, Au, Pt, and Re were analyzed to understand the morphological effects of these promoters on the Ag particles. Cu increases the sintering of Ag particles, while Cd and Re were found to alter the Ag particle sizes into a trimodal distribution. However, contrasting effects of Re and Cd were found on the catalyst activity. Cd−Ag catalysts exhibited a 5-fold increase in the ethylene conversion for a variety of Cd loadings, compared to unpromoted Ag. Moderate increases in conversion and selectivity were seen with the addition of 25 ppm Re, while further Re impregnation led to decreases in ethylene conversion and ethylene oxide selectivity. Au and Pt block surface Ag sites by nucleating as separate particles on the silver surface. In doing so, they reduce the activity of the catalyst, but also reduce the sintering of the Ag particles. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801627k