scholarly journals Kinetics of liquid-phase diphenylacetylene hydrogenation on “single-atom alloy” Pd-Ag catalyst: Experimental study and kinetic analysis

2021 ◽  
Vol 506 ◽  
pp. 111550
Author(s):  
Alexander V. Rassolov ◽  
Igor S. Mashkovsky ◽  
Galina O. Bragina ◽  
Galina N. Baeva ◽  
Pavel V. Markov ◽  
...  
Keyword(s):  
Experimental Study ◽  
Liquid Phase ◽  
Kinetic Analysis ◽  
Single Atom ◽  
Ag Catalyst ◽  
Kinetics Of ◽  
Single Atom Alloy

scholarly journals Liquid-Phase Hydrogenation of 1-Phenyl-1-propyne on the Pd1Ag3/Al2O3 Single-Atom Alloy Catalyst: Kinetic Modeling and the Reaction Mechanism

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3286
Author(s):  
Alexander V. Rassolov ◽  
Igor S. Mashkovsky ◽  
Galina N. Baeva ◽  
Galina O. Bragina ◽  
Nadezhda S. Smirnova ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Liquid Phase ◽  
Reaction Kinetic ◽  
Single Atom ◽  
Kinetic Characteristics ◽  
Liquid Phase Hydrogenation ◽  
Alkyne Hydrogenation ◽  
Kinetics Of ◽  
Al2o3 Catalyst ◽  
Single Atom Alloy

This research was focused on studying the performance of the Pd1Ag3/Al2O3 single-atom alloy (SAA) in the liquid-phase hydrogenation of di-substituted alkyne (1-phenyl-1-propyne), and development of a kinetic model adequately describing the reaction kinetic being also consistent with the reaction mechanism suggested for alkyne hydrogenation on SAA catalysts. Formation of the SAA structure on the surface of PdAg3 nanoparticles was confirmed by DRIFTS-CO, revealing the presence of single-atom Pd1 sites surrounded by Ag atoms (characteristic symmetrical band at 2046 cm−1) and almost complete absence of multiatomic Pdn surface sites (<0.2%). The catalyst demonstrated excellent selectivity in alkyne formation (95–97%), which is essentially independent of P(H2) and alkyne concentration. It is remarkable that selectivity remains almost constant upon variation of 1-phenyl-1-propyne (1-Ph-1-Pr) conversion from 5 to 95–98%, which indicates that a direct alkyne to alkane hydrogenation is negligible over Pd1Ag3 catalyst. The kinetics of 1-phenyl-1-propyne hydrogenation on Pd1Ag3/Al2O3 was adequately described by the Langmuir-Hinshelwood type of model developed on the basis of the reaction mechanism, which suggests competitive H2 and alkyne/alkene adsorption on single atom Pd1 centers surrounded by inactive Ag atoms. The model is capable to describe kinetic characteristics of 1-phenyl-1-propyne hydrogenation on SAA Pd1Ag3/Al2O3 catalyst with the excellent explanation degree (98.9%).

Palladium–gold single atom alloy catalysts for liquid phase selective hydrogenation of 1-hexyne

2017 ◽  
Vol 7 (19) ◽  
pp. 4276-4284 ◽  
Author(s):  
Jilei Liu ◽  
Junjun Shan ◽  
Felicia R. Lucci ◽  
Sufeng Cao ◽  
E. Charles H. Sykes ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Selective Hydrogenation ◽  
Single Atom ◽  
Mild Conditions ◽  
Alloy Catalysts ◽  
Single Atom Alloy ◽  
Single Atom Alloys

Silica supported and unsupported PdAu single atom alloys (SAAs) were investigated for the selective hydrogenation of 1-hexyne to hexenes under mild conditions.

Single-Atom Alloy Pd–Ag Catalyst for Selective Hydrogenation of Acrolein

2015 ◽  
Vol 119 (32) ◽  
pp. 18140-18148 ◽  
Author(s):  
Payoli Aich ◽  
Haojuan Wei ◽  
Bridget Basan ◽  
A. Jeremy Kropf ◽  
Neil M. Schweitzer ◽  
...  
Keyword(s):  
Selective Hydrogenation ◽  
Single Atom ◽  
Ag Catalyst ◽  
Single Atom Alloy

Effect of ionizing radiation on the kinetics of hydrogenation on the Ni-MgO mixed catalyst

1982 ◽  
Vol 47 (7) ◽  
pp. 1780-1786 ◽  
Author(s):  
Rostislav Kudláček ◽  
Jan Lokoč
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Liquid Phase ◽  
Ionizing Radiation ◽  
Oxide Catalyst ◽  
Absorbed Dose ◽  
Hydrogenation Rate ◽  
Solution Composition ◽  
Mixed Catalyst ◽  
Kinetics Of

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.

Kinetics of esterification of monoisopropylphenols with phosphoryl trichloride

1989 ◽  
Vol 54 (5) ◽  
pp. 1311-1317
Author(s):  
Miroslav Magura ◽  
Ján Vojtko ◽  
Ján Ilavský
Keyword(s):  
Liquid Phase ◽  
Rate Constants ◽  
Reaction Rates ◽  
Activation Energies ◽  
The Individual ◽  
Kinetics Of

The kinetics of liquid-phase isothermal esterification of POCl3 with 2-isopropylphenol and 4-isopropylphenol have been studied within the temperature intervals of 110 to 130 and 90 to 110 °C, respectively. The rate constants and activation energies of the individual steps of this three-step reaction have been calculated from the values measured. The reaction rates of the two isomers markedly differ: at 110 °C 4-isopropylphenol reacts faster by the factors of about 7 and 20 for k1 and k3, respectively. This finding can be utilized in preparation of mixed triaryl phosphates, since the alkylation mixture after reaction of phenol with propene contains an excess of 2-isopropylphenol over 4-isopropylphenol.

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

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