Ligand effect in enantioselegtive hydrogenation on skeletal copper-palladium catalysts

1987 ◽  
Vol 36 (2) ◽  
pp. 243-245
Author(s):  
A. A. Vedenyapin ◽  
T. I. Kuznetsova ◽  
E. I. Klabunovskii
Keyword(s):  
Palladium Catalysts ◽  
Ligand Effect ◽  
Skeletal Copper

Behavior of skeletal copper-palladium catalysts in enantioselective hydrogenation

1983 ◽  
Vol 32 (10) ◽  
pp. 1990-1994
Author(s):  
A. A. Vedenyapin ◽  
T. I. Kuznetsova ◽  
E. I. Klabunovskii ◽  
V. M. Akimov ◽  
N. B. Gorina ◽  
...  
Keyword(s):  
Palladium Catalysts ◽  
Enantioselective Hydrogenation ◽  
Skeletal Copper

Model reactions for the study of hydrogenation and acidic activity of palladium catalysts

1987 ◽  
Vol 52 (8) ◽  
pp. 2019-2027 ◽  
Author(s):  
Libor Červený ◽  
Nguyen Thi Du ◽  
Ivo Paseka
Keyword(s):  
Palladium Catalysts ◽  
Styrene Oxide ◽  
Side Reactions ◽  
Pd Catalysts ◽  
Variable Parameters ◽  
Acid Properties ◽  
Liquid Phase Hydrogenation ◽  
Acid Catalysed Reactions ◽  
Different Content ◽  
Model Reactions

Palladium catalysts have been used to study the hydrogenation of 1-phenyl-2-butene-1-ol which is accompanied by several side reactions considered to be acid-catalysed. Another model reaction studied was dehydration and subsequent hydrogenation or hydrogenolysis of 1-phenyl-1,3-propanediol to 3-phenyl-1-propanol, accompanied by formation of propylbenzene. The dehydration and propylbenzene formation can be again classified as acid-catalysed reactions. Another one is methanolysis of styrene oxide taking place under conditions of liquid phase hydrogenation due to the acid properties of Pd-H systems. Hydrogenation activity of Pd catalysts was tested by hydrogenation of cyclohexene. Sixteen Pd catalysts on different supports and with different content of active component were used, their activity and selectivity was determined and the effect of variable parameters in the synthesis of these catalysts on the activity and selectivity is discussed.

Voltammetric Studies of Some Novel Fe(III) Complexes with Quadridentate Ligands. The Axial Ligand-Exchange Reactions in DMF and DMSO

1995 ◽  
Vol 60 (7) ◽  
pp. 1140-1157 ◽  
Author(s):  
Ljiljana S. Jovanovic ◽  
Luka J. Bjelica
Keyword(s):  
Oxidation State ◽  
Chemical Reactions ◽  
Ligand Exchange ◽  
Kinetic Data ◽  
Central Atom ◽  
Axial Ligand ◽  
Exchange Reactions ◽  
Ligand Effect ◽  
Condensation Products ◽  
Voltammetric Studies

The electrochemistry of four novel Fe(III) complexes of the type [Fe(L)Cl], involving quadridentate ligands based on the condensation products of benzoylacetone-S-methylisothiosemicarbazone with salicylaldehyde, 5-chlorosalicylaldehyde, 3,5-dichlorosalicylaldehyde or 5-nitrosalicylaldehyde, was studied in DMF and DMSO at a GC electrode. All complexes undergo a two-step one-electron reductions, usually complicated by chemical reactions. In solutions containing Cl-, the ligand-exchange reactions Cl--DMF and Cl--DMSO take place. Stability of the chloride-containing complexes was discussed in terms of the coordinated ligand effect, oxidation state of the central atom and, in particular, of the donor effect of the solvent. Some relevant kinetic data were calculated.

Attaching Palladium Catalysts to Antibodies

2021 ◽  
pp. 116298
Author(s):  
Paul Cowling ◽  
Mark Bradley ◽  
Annamaria Lilienkampf
Keyword(s):  
Palladium Catalysts

scholarly journals Sintering Activated Atomic Palladium Catalysts with High-Temperature Tolerance of ∼1,000°C

2020 ◽  
pp. 100287
Author(s):  
Nating Yang ◽  
Yonghui Zhao ◽  
Hao Zhang ◽  
Weikai Xiang ◽  
Yuhan Sun ◽  
...  
Keyword(s):  
High Temperature ◽  
Palladium Catalysts ◽  
Temperature Tolerance ◽  
High Temperature Tolerance

scholarly journals Development of Highly Efficient, Glassy Carbon Foam Supported, Palladium Catalysts for Hydrogenation of Nitrobenzene

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1172
Author(s):  
Ádám Prekob ◽  
Mahitha Udayakumar ◽  
Gábor Karacs ◽  
Ferenc Kristály ◽  
Gábor Muránszky ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Glassy Carbon ◽  
Palladium Nanoparticles ◽  
Palladium Catalysts ◽  
Sucrose Solution ◽  
Supported Catalyst ◽  
Carbon Foam ◽  
Hydroxyl Groups ◽  
Polyurethane Elastomers ◽  
Oh Groups

Glassy carbon foam (GCF) catalyst supports were synthesized from waste polyurethane elastomers by impregnating them in sucrose solution followed by pyrolysis and activation (AC) using N2 and CO2 gas. The palladium nanoparticles were formed from Pd(NO3)2. The formed palladium nanoparticles are highly dispersive because the mean diameters are 8.0 ± 4.3 (Pd/GCF), 7.6 ± 4.2 (Pd/GCF-AC1) and 4.4 ± 1.6 nm (Pd/GCF-AC2). Oxidative post-treatment by CO2 of the supports resulted in the formation of hydroxyl groups on the GCF surfaces, leading to a decrease in zeta potential. The decreased zeta potential increased the wettability of the GCF supports. This, and the interactions between –OH groups and Pd ions, decreased the particle size of palladium. The catalysts were tested in the hydrogenation of nitrobenzene. The non-treated, glassy-carbon-supported catalyst (Pd/GCF) resulted in a 99.2% aniline yield at 293 K and 50 bar hydrogen pressure, but the reaction was slightly slower than other catalysts. The catalysts on the post-treated (activated) supports showed higher catalytic activity and the rate of hydrogenation was higher. The maximum attained aniline selectivities were 99.0% (Pd/GCF-AC1) at 293 K and 98.0% (Pd/GCF-AC2) at 323 K.

scholarly journals Development of palladium catalysts modified by ruthenium and molybdenum as anode in direct ethanol fuel cell

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yonis Fornazier Filho ◽  
Ana Caroliny Carvalho da Cruz ◽  
Rolando Pedicini ◽  
José Ricardo Cezar Salgado ◽  
Priscilla Paiva Luz ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Catalysts ◽  
Carbon Support ◽  
X Ray Diffraction ◽  
Direct Ethanol Fuel Cell ◽  
Pd Catalysts ◽  
Bifunctional Mechanism ◽  
Catalytic Activities ◽  
Intrinsic Mechanism ◽  
Ternary Catalysts

AbstractPhysical and electrochemical properties of Pd catalysts combined with Ru and Mo on carbon support were investigated. To this end, Pd, Pd1.3Ru1.0, Pd3.2Ru1.3Mo1.0 and Pd1.5Ru0.8Mo1.0 were synthesized on Carbon Vulcan XC72 support by the method of thermal decomposition of polymeric precursors and then physically and electrochemically characterized. The highest reaction yields are obtained for Pd3.2Ru1.3Mo1.0/C and Pd1.5Ru0.8Mo1.0/C and, as demonstrated by thermal analysis, they also show the smallest metal/carbon ratio compared the other catalysts. XRD (X-ray Diffraction) and Raman analyses show the presence of PdO and RuO2 for the Pd/C and the Pd1.3Ru1.0/C catalysts, respectively, a fact not observed for the Pd3.2Ru1.3 Mo1.0 /C and the Pd1.5Ru0.8Mo1.0/C catalysts. The catalytic activities were tested for the ethanol oxidation in alkaline medium. Cyclic voltammetry (CV) shows Pd1.3Ru1.0/C exhibiting the highest peak of current density, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. From, chronoamperometry (CA), it is possible to observe the lowest rate of poisoning for the Pd1.3Ru1.0/C, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. These results suggested that catalytic activity of the binary and the ternary catalysts are improved in comparison with Pd/C. The presence of RuO2 activated the bifunctional mechanism and improved the catalytic activity in the Pd1.3Ru1.0/C catalyst. The addition of Mo in the catalysts enhanced the catalytic activity by the intrinsic mechanism, suggesting a synergistic effect between metals. In summary, we suggest that it is possible to synthesize ternary PdRuMo catalysts supported on Carbon Vulcan XC72, resulting in materials with lower poisoning rates and lower costs than Pd/C. Graphic abstract

The modifying effect of gallium on the properties of palladium catalysts based on sulfated zirconia

2020 ◽  
Author(s):  
O. E. Bugay ◽  
O. V. Dzhikiya ◽  
M. D. Smolikov ◽  
I. V. Muromtsev ◽  
A. S. Belyi
Keyword(s):  
Sulfated Zirconia ◽  
Palladium Catalysts ◽  
Modifying Effect
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