Effects of Cu over Pd based catalysts supported on silica or niobia
AUTOR(ES)
Roma, M.N.S.C., Cunha, D.S., Cruz, G.M., Cobo, A.J.G.
FONTE
Brazilian Journal of Chemical Engineering
DATA DE PUBLICAÇÃO
2000-12
RESUMO
Palladium and palladium-copper catalysts supported on silica and niobia were characterized by H2 chemisorption and H2-O2 titration. Systems over silica were also analyzed by transmission electron microscopy and EXAFS. The metallic dispersion decreased from 20% to 7% when the content of Pd was increased from 0.5wt.-% to 3wt.-% in monometallic catalysts. The addition of 3 wt.-% Cu to obtain Pd-Cu catalysts caused a remarkable capacity loss of hydrogen chemisorption. TPR analysis suggested an interaction between the two metals and EXAFS characterization of the catalyst supported on silica confirmed the formation of Pd-Cu alloy. Pd/Nb2O5 catalysts showed turnover numbers higher than those obtained with the Pd/SiO2 systems in the cyclohexane dehydrogenation. However, the bimetallic catalysts showed very low turnover numbers.
Documentos Relacionados
- REMOVAL OF NITRATE FROM DRINKING WATER BY USING PdCu STRUCTURED CATALYSTS BASED ON CORDIERITE MONOLITHS
- Selective Hydrogenolysis of Glycerol to 1,2-Propanediol Over Bimetallic Cu-Ni Catalysts Supported on γ-Al2O3
- SYNTHESIS AND THEORETICAL STUDY OF HPW CATALYSTS SUPPORTED ON NIOBIA CALCINATED AT 500 AND 600 ºC
- Hidrogenólise de glicerol catalisada por Pt, Pd e Ru suportados em nióbia, alumina e suas misturas
- Effects of impregnation methods and drying conditions on quinoline hydrodenitrogenation over Ni-W based catalysts