TY - JOUR
T1 - The relation between surface composition of Pd-Cu/ACC catalysts prepared by selective deposition and their denitrification behavior
AU - Matatov-Meytal, Uri
AU - Sheintuch, Moshe
N1 - Funding Information:
U-MM gratefully acknowledges the financial support of the Centre for Adsorption in Science of the Ministry of Immigrant Absorption and the Committee for Planning and Budgeting of the Council for Higher Education.
PY - 2009/3/30
Y1 - 2009/3/30
N2 - Pd-Cu catalysts supported on activated carbon cloth (Pd-Cu/ACC), prepared by selective catalytic deposition, showed a high activity (92% conversion) and selectivity (ca 93%) in the liquid phase hydrogenation of nitrates to nitrogen. From this study, first knowledge on the surface composition of a family of Cu-2 wt%Pd/AC bimetallic catalysts and their remarkable influence on the catalytic behavior in nitrate hydrogenation could be obtained. The results of the surface composition determination by the combination of CO chemisorption and HRSEM reveal a specific orientation for the Cu metal deposition on the core Pd crystallites, probably of Pd-Cu bimetallic islets and free Pd atoms. The main differences between samples with different Cu loadings are attributed to changes in these two metallic phases over the surface of metallic particles and they are reflected in the activity and selectivity of nitrate hydrogenation. The results reveal that TOFCu, i.e., the number of nitrate ions consumed per second per active surface Cu seems to be independent of surface composition, while TOFPd was found to increase with surface Cu, indicating the bifunctional nature of the Cu-Pd sites responsible for the nitrate reduction by red-ox reaction. Also, the surface ratio of Pd-Cu sites that catalyze nitrate-to-nitrite hydrogenation, to Pd sites, which catalyze the hydrogenation of nitrite to nitrogen, should be optimal. This might offer novel possibilities for the design of fibrous catalyst showing better performance.
AB - Pd-Cu catalysts supported on activated carbon cloth (Pd-Cu/ACC), prepared by selective catalytic deposition, showed a high activity (92% conversion) and selectivity (ca 93%) in the liquid phase hydrogenation of nitrates to nitrogen. From this study, first knowledge on the surface composition of a family of Cu-2 wt%Pd/AC bimetallic catalysts and their remarkable influence on the catalytic behavior in nitrate hydrogenation could be obtained. The results of the surface composition determination by the combination of CO chemisorption and HRSEM reveal a specific orientation for the Cu metal deposition on the core Pd crystallites, probably of Pd-Cu bimetallic islets and free Pd atoms. The main differences between samples with different Cu loadings are attributed to changes in these two metallic phases over the surface of metallic particles and they are reflected in the activity and selectivity of nitrate hydrogenation. The results reveal that TOFCu, i.e., the number of nitrate ions consumed per second per active surface Cu seems to be independent of surface composition, while TOFPd was found to increase with surface Cu, indicating the bifunctional nature of the Cu-Pd sites responsible for the nitrate reduction by red-ox reaction. Also, the surface ratio of Pd-Cu sites that catalyze nitrate-to-nitrite hydrogenation, to Pd sites, which catalyze the hydrogenation of nitrite to nitrogen, should be optimal. This might offer novel possibilities for the design of fibrous catalyst showing better performance.
KW - Activated carbon cloth support
KW - Bimetallic catalysts
KW - Copper
KW - Hydrogenation
KW - Nitrates
KW - Palladium
KW - Selective deposition
UR - http://www.scopus.com/inward/record.url?scp=61849124730&partnerID=8YFLogxK
U2 - 10.1016/j.catcom.2008.10.038
DO - 10.1016/j.catcom.2008.10.038
M3 - 文章
AN - SCOPUS:61849124730
SN - 1566-7367
VL - 10
SP - 1137
EP - 1141
JO - Catalysis Communications
JF - Catalysis Communications
IS - 8
ER -