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Catalytic performance of rhodium-based catalysts for CO preferential oxidation in H2-rich gases / Camilla Karnfelt in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5304–5312 Titre : Catalytic performance of rhodium-based catalysts for CO preferential oxidation in H2-rich gases Type de document : texte imprimé Auteurs : Camilla Karnfelt, Auteur ; Stefania Specchia, Auteur ; Guido Saracco, Auteur Année de publication : 2008 Article en page(s) : p. 5304–5312 Note générale : Bibliogr. p. 5311-5312 Langues : Anglais (eng) Mots-clés : Rhodium-based  catalysts;  CO  preferential  oxidation;  Gas Résumé : CO preferential oxidation (CO-PROX) can lead to a reduction of the CO content in the hydrogen-rich gas derived from hydrocarbon re-forming down to at least 10 ppmv or below, so as to enable its direct feed to standard polymer electrolyte membrane fuel cells (PEM FCs). Rh-based catalysts supported on A zeolites (3A, 4A, and 5A), alumina, titania, and ceria were prepared and tested for potential application in CO-PROX operating over a temperature range compatible with PEM FCs (80−100 °C). Among the prepared catalysts, the 1% Rh-zeolite 3A catalyst, tested with a weight space velocity (WSV) of 0.66 N·L·min−1·gcat.−1, was found to be the most suitable one for the CO-PROX at low temperature: it reduced the inlet CO concentration below 10 ppmv within a temperature range of at least 80−120 °C without the appearance of undesirable side reactions. Tests at progressively lower O-to-CO feed ratio and the same WSV value were carried out for the sake of reducing H2 consumption and improving CO-PROX selectivity. For 1% Rh-3A zeolite the minimum λ value, ensuring a sufficiently wide temperature range of a nearly complete CO conversion at temperatures compatible with PEM FCs operation, was found to be equal to 3. Finally, to decrease the catalyst cost, the Rh load on the catalyst was tentatively reduced from 1 to 0.5%. A better distribution of the active element crystallites over the support surface was even obtained for this last catalyst. When operating at λ = 3 and at WSV = 0.66 N·L·min−1·gcat.−1, the 0.5% Rh-3A catalyst could effectively reduce the inlet CO concentration below 10 ppmv within a temperature range of 100−140 °C, without the appearance of undesired side reactions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0713588 [article] Catalytic performance of rhodium-based catalysts for CO preferential oxidation in H2-rich gases [texte imprimé] / Camilla Karnfelt, Auteur ; Stefania Specchia, Auteur ; Guido Saracco, Auteur . - 2008 . - p. 5304–5312. Bibliogr. p. 5311-5312 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5304–5312 Mots-clés : Rhodium-based  catalysts;  CO  preferential  oxidation;  Gas Résumé : CO preferential oxidation (CO-PROX) can lead to a reduction of the CO content in the hydrogen-rich gas derived from hydrocarbon re-forming down to at least 10 ppmv or below, so as to enable its direct feed to standard polymer electrolyte membrane fuel cells (PEM FCs). Rh-based catalysts supported on A zeolites (3A, 4A, and 5A), alumina, titania, and ceria were prepared and tested for potential application in CO-PROX operating over a temperature range compatible with PEM FCs (80−100 °C). Among the prepared catalysts, the 1% Rh-zeolite 3A catalyst, tested with a weight space velocity (WSV) of 0.66 N·L·min−1·gcat.−1, was found to be the most suitable one for the CO-PROX at low temperature: it reduced the inlet CO concentration below 10 ppmv within a temperature range of at least 80−120 °C without the appearance of undesirable side reactions. Tests at progressively lower O-to-CO feed ratio and the same WSV value were carried out for the sake of reducing H2 consumption and improving CO-PROX selectivity. For 1% Rh-3A zeolite the minimum λ value, ensuring a sufficiently wide temperature range of a nearly complete CO conversion at temperatures compatible with PEM FCs operation, was found to be equal to 3. Finally, to decrease the catalyst cost, the Rh load on the catalyst was tentatively reduced from 1 to 0.5%. A better distribution of the active element crystallites over the support surface was even obtained for this last catalyst. When operating at λ = 3 and at WSV = 0.66 N·L·min−1·gcat.−1, the 0.5% Rh-3A catalyst could effectively reduce the inlet CO concentration below 10 ppmv within a temperature range of 100−140 °C, without the appearance of undesired side reactions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0713588

Structures de guidage hyperfréquences / Michel Ney

Public ISBD in Techniques de l'ingénieur : électronique Ti350. Electromagnetisme, propagation / Guillaume Bernard  Titre : Structures de guidage hyperfréquences : propagation et géométrie : réf. internet E 1170 Type de document : texte imprimé Auteurs : Michel Ney, Auteur ; Camilla Karnfelt, Auteur Editeur : Paris : Techniques de l'ingénieur Année de publication : 2015 Importance : p. 203 - 227 Note générale : Bibliogr. p. 227 Langues : Français (fre) Mots-clés : Structures  de  guidage  --  hyperfréquences Note de contenu : Sommaire: 1. Propagation sur les structures de guidage fondamentales 2. Évolution des géométries développées 3. Conclusion 4. Glossaire – définitions in Techniques de l'ingénieur : électronique Ti350. Electromagnetisme, propagation / Guillaume Bernard  Structures de guidage hyperfréquences : propagation et géométrie : réf. internet E 1170 [texte imprimé] / Michel Ney, Auteur ; Camilla Karnfelt, Auteur . - Paris : Techniques de l'ingénieur, 2015 . - p. 203 - 227. Bibliogr. p. 227 Langues : Français (fre) Mots-clés : Structures  de  guidage  --  hyperfréquences Note de contenu : Sommaire: 1. Propagation sur les structures de guidage fondamentales 2. Évolution des géométries développées 3. Conclusion 4. Glossaire – définitions

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