The influence of Pd–Ag catalyst restructuring on the activation energy for ethylene hydrogenation in ethylene–acetylene mixtures

Monodispersed Pd-nanoparticles on carbon fiber fabrics as structured catalyst for selective hydrogenation

“…4b) and found to be − H Y = 30 kJ mol −1 , − H E = 21 kJ mol −1 , − H H 2 = 28 kJ mol −1 . These values are in fair agreement with the reported for liquidand gas-phase hydrogenations over Pd-group catalysts (Singh and Vannice, 1999;Vattuone et al, 2000;Vincent and Gonzalez, 2001;Zea et al, 2005).…”

New Approach to Ammonia Synthesis by Catalysis in Magnetic Field

“…Both reactions are exothermic and this is according to the theory of ammonia synthesis by the Haber Bosch process. The activation energy of Pd/SiO 2 catalyst was 27.7 kcal/mol at 500 o C and it was dropped by the presence of Ag [18]. Other researcher found that the activation energy of Nibased catalyst for methane production was 90.9, 111.8, 79.5, and 85.9 kJ/mol, respectively [19].…”

Recent advances in silver-based heterogeneous catalysts for green chemistry processes

“…The TPD results show that the addition of Ag to Pd suppresses the overall hydrogenation activity but increases selectivity towards ethylene. Zea et al[71] investigated how reconstruction of bimetallic Pd-Ag surfaces, and the presence of a co-adsorbed CO, work together to alter the reaction behavior of an industrially significant selective hydgrogenation reaction.Sales et al[79] reported a Pd-Ag/γ-Al 2 O 3 catalyst prepared by precipitation in a liquid polyol and applied it to the hydrogenation of hexa-1,5-diene in liquid phase at 40°C. The addition of silver improved the hex-1-ene fractional selectivity in all cases, but lowered the catalyst activity when the Pd/Ag ratio was approximately unity.…”