Hydrogenation of Nitro Compounds over Catalytic Systems Containing Rare-Earth Oxides

2021 ◽  
Vol 316 ◽  
pp. 684-688
Author(s):  
G. M. Kurunina ◽  
O.M. Ivankina ◽  
G.M. Butov
Keyword(s):  
Rare Earth ◽  
Palladium Catalysts ◽  
Nitro Compounds ◽  
Rare Earth Oxides ◽  
Partial Replacement ◽  
Hydrogenation Rate ◽  
Catalytic Systems ◽  
Liquid Phase Hydrogenation ◽  
The Individual ◽  
Reference Catalyst

The paper studies the activity of 1 % palladium catalysts containing rare earth oxides (REOs) and alumina as a carrier in the hydrogenation of nitro compounds exemplified by nitrobenzene and o-nitro anisole. Under the liquid-phase hydrogenation conditions, these catalytic systems provide high selectivity of the process and a quantitative yield. It has been found that the partial replacement of Al2O3 with REO allows increasing the hydrogenation rate by 5–6 times, as compared with the reference catalyst and by 1.2–1.7 times as compared with the individual carrier. The oxide mixtures (REO and Al2O3) containing 20–40 % REO allow reaching the same hydrogenation rate with that over an REO-containing 1 % Pd catalyst.

Hydrogenation of Para-Nitrotoluene on Catalytic Systems Containing Oxides of Rare Earth Elements

2021 ◽  
Vol 410 ◽  
pp. 389-393
Author(s):  
Galina M. Kurunina ◽  
Olga M. Ivankina ◽  
Gennady M. Butov
Keyword(s):  
Rare Earth ◽  
Reaction Rate ◽  
High Selectivity ◽  
Nitro Compounds ◽  
Aqueous Alcohol ◽  
Hydrogenation Rate ◽  
Catalytic Systems ◽  
Liquid Phase Hydrogenation ◽  
Aqueous Alcohol Solutions ◽  
Hydrogenation Reactions

This work is devoted to the study of the activity of 1% platinum catalysts containing rare earth element oxides (OREE) - Gd2O3, Ce2O3 and aluminum oxide as a carrier in the hydrogenation reactions of nitro compounds on the example of n-nitrotoluene. These catalytic systems in the conditions of liquid-phase hydrogenation provide high selectivity of the process and practically quantitative yield. The process was controlled by the potentiometric method, the reaction rate was judged by the amount of hydrogen absorbed per unit time. It is found that 20% and higher aqueous alcohol solutions can be used as a solvent during hydrogenation. It was found that the initial hydrogenation rate for 1% Pt/Gd2O3 is 3.2 times higher, and for 1% Pt/Ce2O3 Cerium it is 1.6 times higher relative to the 1% Pt/Al2O3 comparison catalyst.

scholarly journals SUPPORTED PALLADIUM CATALYSTS FOR SELECTIVE LIQUID-PHASE HYDROGENATION OF AROMATIC NITRO COMPOUNDS

2021 ◽  
Vol 14 (03) ◽  
pp. 1795-1802
Author(s):  
L.R. Sassykova ◽  
A.R. Sassykova ◽  
B.T. Dossumova ◽  
M. S. Ilmuratova ◽  
N. E. Maximov ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Palladium Catalysts ◽  
Nitro Compounds ◽  
Supported Palladium Catalysts ◽  
Aromatic Nitro Compounds ◽  
Liquid Phase Hydrogenation ◽  
Supported Palladium ◽  
Aromatic Nitro

Effect of Rare Earth Oxides on Electrical Properties of Spark Plasma Sintered AlN Ceramics

2015 ◽  
Vol 30 (3) ◽  
pp. 267
Author(s):  
HUANG Lin-Yun ◽  
LI Chen-Hui ◽  
KE Wen-Ming ◽  
SHI Yu-Sheng ◽  
HE Zhi-Yong ◽  
...  
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Rare Earth Oxides ◽  
Spark Plasma

A glance on rare earth oxides: importance, reserves, demand, applications, critical uncertainties, global economy, and zeta potential characterization

2020 ◽  
Vol 05 ◽  
Author(s):  
Silas Santos ◽  
Orlando Rodrigues ◽  
Letícia Campos
Keyword(s):  
Rare Earth ◽  
Zeta Potential ◽  
Sample Preparation ◽  
Rare Earths ◽  
Smart Materials ◽  
Global Economy ◽  
Materials Science ◽  
Functional Materials ◽  
Rare Earth Oxides ◽  
Interparticle Forces

Background: Innovation mission in materials science requires new approaches to form functional materials, wherein the concept of its formation begins in nano/micro scale. Rare earth oxides with general form (RE2O3; RE from La to Lu, including Sc and Y) exhibit particular proprieties, being used in a vast field of applications with high technological content since agriculture to astronomy. Despite of their applicability, there is a lack of studies on surface chemistry of rare earth oxides. Zeta potential determination provides key parameters to form smart materials by controlling interparticle forces, as well as their evolution during processing. This paper reports a study on zeta potential with emphasis for rare earth oxide nanoparticles. A brief overview on rare earths, as well as zeta potential, including sample preparation, measurement parameters, and the most common mistakes during this evaluation are reported. Methods: A brief overview on rare earths, including zeta potential, and interparticle forces are presented. A practical study on zeta potential of rare earth oxides - RE2O3 (RE as Y, Dy, Tm, Eu, and Ce) in aqueous media is reported. Moreover, sample preparation, measurement parameters, and common mistakes during this evaluation are discussed. Results: Potential zeta values depend on particle characteristics such as size, shape, density, and surface area. Besides, preparation of samples which involves electrolyte concentration and time for homogenization of suspensions are extremely valuable to get suitable results. Conclusion: Zeta potential evaluation provides key parameters to produce smart materials seeing that interparticle forces can be controlled. Even though zeta potential characterization is mature, investigations on rare earth oxides are very scarce. Therefore, this innovative paper is a valuable contribution on this field.

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.

Critical Current of Bi-2212 Single Crystal by Doping Oxides as a Pinning Center

2014 ◽  
Vol 95 ◽  
pp. 175-180
Author(s):  
Takuya Agou ◽  
Hiroya Imao
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Single Crystals ◽  
Crystal Surface ◽  
Rare Earth Oxides ◽  
Pinning Centers ◽  
Current Path ◽  
Pinning Center ◽  
Superconducting Current ◽  
A Current

It is necessary to formpinning centers in superconductors to allow the flow of large currents throughthe specimens. To clarify the properties of pinning centers, it is preferableto investigate single crystals. In this study, heat treatment was used to dopevarious oxides into Bi2Sr2CaCu2Ox(Bi-2212) single crystals prepared by self-flux methods and the criticalcurrent (Ic) was measured. The oxides used in this study were Al2O3and the rare earth oxides Er2O3and Nd2O3. At 77K, Nd2O3and Er2O3 are magnetic, whereas Al2O3is nonmagnetic. The Ic of the samples were measured as a current per width of 1cm (Ics). The resulting Ics of the Bi-2212 single crystal was 2.8A/cm and thatof the Al2O3 doped Bi-2212 sample was 4.5A/cm. Comparedwith these samples, doping the other rare earth oxides gave Ics values inexcess 10A/cm. The results indicated that the doping oxides were effective inoperating as pinning centers in the samples. We assumed the current path in asingle crystal, and calculated the Ics by superconducting current simulation.The results indicated that the oxides permeated from a crystal surface in aporous shape. The oxides increase the current which flow in the Cu-O2planes that are parallel to the a-b plane.

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