Hydroxyapatite as a bifunctional nanocatalyst for solventless Henry reaction: A demonstration of morphology dependent catalysis

2022 ◽  
Author(s):  
Smriti Mukherjee ◽  
Iyyappan E ◽  
Keerthi Satheesh ◽  
Elsa Maria Jordi ◽  
Saranya S ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Precipitation ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
Current Investigation ◽  
Henry Reaction

In the current investigation, HA nanorods and nanoplates with a high surface area have been synthesized using the chemical precipitation method via alcogel formation employing L-arginine as a crystal growth...

Crystal growth in supercritical ammonia using high surface area silicon nitride feedstock

2004 ◽  
Vol 261 (1) ◽  
pp. 99-104 ◽  
Author(s):  
Stefan Kaskel ◽  
Meikh Khanna ◽  
Bodo Zibrowius ◽  
Hans-Werner Schmidt ◽  
Dirk Ullner
Keyword(s):  
Crystal Growth ◽  
Silicon Nitride ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Supercritical Ammonia

Thermal Stabilization of γ-Al2O3 with Modification of Polyethylene Glycol by Reverse Precipitation Method

2012 ◽  
Vol 560-561 ◽  
pp. 169-173
Author(s):  
Yu Sheng Wu ◽  
Jiao Ma ◽  
Fang Hu
Keyword(s):  
Polyethylene Glycol ◽  
Surface Area ◽  
High Surface ◽  
Catalyst Support ◽  
High Surface Area ◽  
Thermal Stabilization ◽  
Treatment Temperature ◽  
Precipitation Method ◽  
Different Content ◽  
Reverse Precipitation

A series of γ-Al2O3 modified with different content of polyethylene glycol (PEG) was prepared by a reverse precipitation method. The phase transformation, thermal stabilization and the morphology of PEG-modified γ-Al2O3 was studied by XRD, BET and TEM, respectively. The results showed that the γ-Al2O3 with 1mol% PEG-modified has the excellent thermal stabilization after calcined at 1100°C for 3h. With the content of PEG increasing, the surface area of γ-Al2O3 was reduced gradually. Simultaneity, the γ-Al2O3 phase was transferred to θ-Al2O3 with the surface area 92 m2g-1 and a pore volume of 0.77 cm3g-1. The high surface area maintained at such high treatment temperature shows the 1mol% PEG-modified γ-Al2O3 prepared by reverse precipitation method can be applied in the automotive three-way catalyst support.

Synthesis and Hydrodesulfurization Performance of Bulk Ni-Mo-W Catalyst with High Surface Area

2013 ◽  
Vol 634-638 ◽  
pp. 604-607
Author(s):  
Hai Bin Yu ◽  
Jing Cheng Zhang ◽  
Jun Nan ◽  
Shan Geng ◽  
Yu Ting Zhang ◽  
...  
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Great Influence ◽  
Precipitation Method ◽  
High Catalytic Activity ◽  
Organic Sulfur Compounds ◽  
Hydrodesulfurization Catalysts ◽  
Deep Desulfurization ◽  
Complex Organic

Bulk Ni-Mo-W hydrodesulfurization catalysts with high catalytic activity were synthesized via direct precipitation and controlled pH precipitation method, respectively. Analysis results shows that the preparation method has great influence on the morphology and pore structure, and further influence the hydrodesulfurization activity. The catalyst synthesized by controlled pH precipitation method has much higher surface area and pore volume, 132.9 m2/g and 0.30 mL/g, due to its developed porous structure accumulated by small crystal particles. The activity evaluation indicates that the bulk Ni-Mo-W hydrodesulfurization catalysts has good ultra-deep desulfurization activity of removing complex organic sulfur compounds, such as DBT and Cn-DBT.

Influences of Physicochemical Properties of ZnO on the Adsorptive Desulfurization Performance of Ni/ZnO Adsorbent

2012 ◽  
Vol 581-582 ◽  
pp. 418-421 ◽  
Author(s):  
Zhang Yong Liu
Keyword(s):  
Physicochemical Properties ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Precipitation Method ◽  
Adsorptive Desulfurization ◽  
Support Materials ◽  
Sulfur Adsorption ◽  
Ppm Level ◽  
Nanosize Zno

ZnO nanoparticles with high surface area were synthesized by hydrothermal homogeneous precipitation method, and the influences of physicochemical properties of ZnO materials on the adsorptive desulfurization performance of Ni/ZnO adsorbent were investigated. Activity evaluation showed that the Ni/ZnO adsorbent using nanosize ZnO as support materials had better adsorption performance, and the sulfur adsorption capacity was maximized depending on the surface area and particle size of ZnO materials. The thiophene removal efficiency and the breakthrough capacity (10 ppm level) were found to be 100% and 6.1 (mg of sulfur per g of adsorbent), respectively.

scholarly journals High-surface-area activated red mud for efficient removal of methylene blue from wastewater

2017 ◽  
Vol 36 (1-2) ◽  
pp. 62-79 ◽  
Author(s):  
Zhong-Pan Hu ◽  
Ze-Min Gao ◽  
Xinying Liu ◽  
Zhong-Yong Yuan
Keyword(s):  
Methylene Blue ◽  
Surface Area ◽  
Red Mud ◽  
High Surface ◽  
High Surface Area ◽  
Influence Factors ◽  
Interaction Mechanism ◽  
Precipitation Method ◽  
Order Kinetic ◽  
Alkaline Conditions

Red mud was activated by a digestion–precipitation method, resulting in a mesostructure with high surface area, and the activated red mud was further used as the adsorbent for methylene blue removal. The physicochemical properties of the resultant samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry analysis, and nitrogen sorption techniques. Batch studies were measured to investigate the influence factors including adsorbent dosage, contact time, pH, and initial concentration. It was revealed that the activated red mud was highly efficient for removal of methylene blue. Adsorption experiments were found to be better achieved in faintly acidic and alkaline conditions, where the adsorption capacity of activated red mud and activated red mud-200 reached 232 and 274 mg/g at pH 7.0, respectively. Langmuir, Freundlich, Temkin isotherms, and pseudo-second-order kinetic model fitted the experimental data well, demonstrating an electrostatic interaction mechanism.

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