Improvement of zeolite adsorption and catalytic properties by precisely controlling its particle morphology

2022 ◽  
Author(s):  
Shiying Li ◽  
Huanhuan Yang ◽  
Sen Wang ◽  
Jianguo Wang ◽  
Weibin Fan ◽  
...  
Keyword(s):  
Porous Structure ◽  
Catalytic Properties ◽  
Molecular Size ◽  
Particle Morphology ◽  
Chemical Compositions

Aluminosilicate zeolite has a porous structure with opening comparable to molecular size, which endows it with unique adsorptive and catalytic properties that are highly dependent on its chemical compositions and...

Preparation of copper compounds of different compositions and particle morphologies

1991 ◽  
Vol 6 (4) ◽  
pp. 766-777 ◽  
Author(s):  
Stanka Kratohvil ◽  
Egon Matijević
Keyword(s):  
Essential Role ◽  
Solid Phase ◽  
Particle Morphology ◽  
Chemical Compositions ◽  
Rapid Phase ◽  
Copper Compounds ◽  
Sulfate Solutions ◽  
Amorphous Particles ◽  
Particle Shapes ◽  
Nitrate Solutions

Copper compounds of different chemical compositions and particle shapes were prepared by homogeneous precipitation from copper salt solutions in the presence of urea. It was demonstrated that the nature of the anions played an essential role in the properties of the generated solid phase. Thus, Cu(II)-nitrate solutions yielded spherical amorphous particles which had the composition of malachite [Cu2(OH)2CO3], the Cu(II)-chloride solutions gave bipyramidal particles of atacamite [CuCl2 · 3Cu(OH)2], and in Cu(II)-sulfate solutions needle-shaped brochantite [3Cu(OH)2 · CuSO4] or platelets of posnjakite [3Cu(OH)2 · CuSO4 · H2O] were formed. The addition of NaOH to prepared dispersions resulted in a rapid phase transformation of all above solids into needle-like Cu(OH)2. Calcination of various copper basic compounds at 700–800 °C temperature produced CuO, while the particle morphology was retained.

scholarly journals A Study of the Catalytic Properties of Synthetic Aluminosilicates of Different Morphologies in Cracking Reactions of the Byproducts of Isoprene Synthesis

2021 ◽  
Vol 47 (5) ◽  
pp. 469-480
Author(s):  
Yu. A. Alikina ◽  
E. A. Spetsov ◽  
N. Yu. Ulyanova ◽  
O. Yu. Golubeva
Keyword(s):  
Catalytic Activity ◽  
Aluminum Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Catalytic Properties ◽  
Raw Materials ◽  
Layered Silicates ◽  
Chemical Compositions ◽  
Cyclic Compounds ◽  
Isoprene Synthesis

Abstract The catalytic activity of synthetic samples of aluminosilicates of various morphologies and chemical compositions in a cascade of reactions that are byproducts (BPs) in the decomposition process of 4,4‑dimethyl-1,3-dioxane is studied. Aluminosilicates with montmorillonite structures (Na0.2Al1.8Mg0.2Si4O10(OH)2⋅nH2O, Mg3Si4O10(OH)2⋅nH2O), and kaolinite (Al2Si2O5(OH)4) with the spherical and platy morphologies of particles, as well as their porous-textural characteristics and surface properties, are studied. It is shown that the specific surface area of the studied samples, depending on the composition, varies from 11 to 470 m2/g, and the content of aluminum oxide in the samples ranged from 0 to 24 wt %. It is found that layered silicates with a montmorillonite structure contribute to reducing the gasification of organic raw materials and increasing the yield of isoprene. Kaolinite with a spherical morphology of particles increases the yield of formaldehyde, and with a platy morphology of particles, it increases the degree of decomposition of heteroatomic and cyclic compounds.

Variations in the synthesis of barium hexaferrite doped with iridium and its effect in the catalytic combustion of hydrocarbons

1998 ◽  
Vol 13 (6) ◽  
pp. 1637-1643 ◽  
Author(s):  
A. C. Pierre ◽  
A. Favre ◽  
N. Guilhaume
Keyword(s):  
Porous Structure ◽  
Catalytic Combustion ◽  
Catalytic Properties ◽  
Barium Hexaferrite ◽  
Metal Salts ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Bet Analysis ◽  
Structure Phase

This paper discusses the influence of the synthesis technique on the porous structure, phase transformation, and catalytic properties of barium hexaferrite. Barium hexaferrite was synthesized by two different citrate gel methods. The first one involved metal salts, citric acid, and ammonia, while the second dispersed the same components in a polyacrylamide gel. X-ray diffraction analysis was used to determine the nature of the phase while the Brunauer, Emmett, and Teller (BET) analysis was used to study the porous structure of the material which were heat-treated at 700 °C, 900 °C, and 1200 °C. The catalytic activity of all materials in the combustion of methane was also measured.

scholarly journals Pd-Ru Bimetallic Nanocrystals with a Porous Structure and Their Enhanced Catalytic Properties

2018 ◽  
Vol 35 (5) ◽  
pp. 1700386 ◽  
Author(s):  
Shulin Wan ◽  
Qingxiao Wang ◽  
Haihang Ye ◽  
Moon J. Kim ◽  
Xiaohu Xia
Keyword(s):  
Porous Structure ◽  
Catalytic Properties ◽  
Bimetallic Nanocrystals

Effects of Eu Doping and Calcination Temperatures on Chemical Compositions, Microstructure and Luminescent Intensity of BaAl2O4

2018 ◽  
Vol 766 ◽  
pp. 233-240
Author(s):  
Oratai Jongprateep ◽  
Kritthin Chunwijitra
Keyword(s):  
Particle Morphology ◽  
Secondary Phase ◽  
Chemical Compositions ◽  
Luminescent Intensity ◽  
Forgery Detection ◽  
Solution Combustion ◽  
Calcination Temperatures ◽  
Secondary Phase Formation ◽  
Crack Monitoring ◽  
Combustion Technique

Photoluminescent (PL) materials are commonly utilized in applications such as leakage test, crack monitoring, banknote forgery detection, and fingerprint detection. Doping, chemical compositions and microstructure, are generally accepted as factors that influence luminescent intensity of spinel-structure phosphors such as SrAl2O4, CaAl2O4, and BaAl2O4. This study aimed at synthesizing BaAl2O4 photoluminescent powders by solution combustion technique. Effects of Eu doping and calcination temperatures on chemical compositions, microstructure and luminescent intensity of the materials were also examined. Experimental results indicated that Eu concentrations did not exhibit a significant effect on chemical composition and particle morphology. Higher calcination temperatures, on the contrary, resulted in reduction of secondary phase formation, and in alteration of morphology of particles and pores. The greatest luminescent intensity was achieved in the BaAl2O4 sample with 3 mol% Eu subjected to calcination at 900°C. Enhancement of the luminescent intensity in this sample might be attributed to minimal secondary phase and pore content.

scholarly journals Effect of Structure-Controlled Ruthenium Oxide by Nanocasting in Electrocatalytic Oxygen and Chlorine Evolution Reactions in Acidic Conditions

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 549 ◽  
Author(s):  
Jisu Han ◽  
Hyung Jun An ◽  
Tae-Wan Kim ◽  
Kwan-Young Lee ◽  
Hyung Ju Kim ◽  
...  
Keyword(s):  
Porous Structure ◽  
Catalytic Properties ◽  
High Surface ◽  
High Surface Area ◽  
Ruthenium Oxide ◽  
Chlorine Evolution ◽  
Electrocatalytic Properties ◽  
Acidic Conditions ◽  
Ordered Porous ◽  
Effect Of Structure

RuO2 has been used for various applications because of its good catalytic properties. To further improve its electrocatalytic properties, we used a nanocasting technique. By using this technique, we obtained structure-controlled (SC) RuO2 with a high surface area and an ordered porous structure, which created enhanced electrocatalytic properties over commercial RuO2 nanoparticles for both oxygen and chlorine evolution reactions.

Peculiarities of formation of phase composition, porous structure, and catalytic properties of tungsten oxide-based macroporous materials fabricated by sol–gel synthesis

2014 ◽  
Vol 88 ◽  
pp. 42-51 ◽  
Author(s):  
Evgeniy Konstantinovich Papynov ◽  
Vitaliy Yurevich Mayorov ◽  
Marina Sergeevna Palamarchuk ◽  
Valentin Aleksandrovich Avramenko
Keyword(s):  
Phase Composition ◽  
Porous Structure ◽  
Tungsten Oxide ◽  
Catalytic Properties ◽  
Sol Gel ◽  
Macroporous Materials ◽  
Sol Gel Synthesis
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