Accelerated catalytic activity of Pd NPs supported on amine-rich silica hollow nanospheres for quinoline hydrogenation

2017 ◽  
Vol 7 (11) ◽  
pp. 2221-2227 ◽  
Author(s):  
Miao Guo ◽  
Can Li ◽  
Qihua Yang
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Small Particle ◽  
High Surface ◽  
High Catalytic Activity ◽  
Small Particle Size ◽  
Hollow Nanospheres ◽  
Hollow Nanosphere ◽  
Surface Electron ◽  
Solid Catalysts

The ultra-small Pd NPs stabilized by the amine-rich silica hollow nanosphere with a TOF as high as 5052 h−1 are among the most active solid catalysts for quinoline hydrogenation. The high catalytic activity could be mainly attributed to the ultra-small particle size and high surface electron density of Pd NPs.

Synthesis of ultrafine amorphous PtP nanoparticles and the effect of PtP crystallinity on methanol oxidation

RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 20722-20728 ◽  
Author(s):  
Yanjiao Ma ◽  
Hui Wang ◽  
Hao Li ◽  
Julian Key ◽  
Shan Ji ◽  
...  
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Carbon Black ◽  
Methanol Oxidation ◽  
Small Particle ◽  
Amorphous Structure ◽  
High Catalytic Activity ◽  
Small Particle Size ◽  
Electrocatalytic Performance ◽  
Different Levels

Ultrafine amorphous PtP nanoparticles supported on carbon black were prepared. Comparison of electrocatalytic performance of the samples with different levels of crystallinity showed ultrafine amorphous PtP nanoparticles have high catalytic activity for methanol oxidation due to their small particle size and amorphous structure.

Shaping Strategies for Porous Ti Fabrication throughout Colloidal Chemistry

2016 ◽  
Vol 704 ◽  
pp. 406-412 ◽  
Author(s):  
Esther Molero ◽  
Antonio Javier Sanchez-Herencia ◽  
Roberto G. das Neves ◽  
Elena Gordo ◽  
Begoña Ferrari
Keyword(s):  
Particle Size ◽  
Small Particle ◽  
Fine Particles ◽  
High Surface ◽  
High Reactivity ◽  
Surface Reactivity ◽  
Metal Powders ◽  
Small Particle Size ◽  
Foaming Agents ◽  
Porous Ti

Aimed by reducing the total cost of products, powder metallurgy (PM) processing of Ti is a subject of high interest. However, using of conventional PM techniques presents difficulties due to the intrinsic characteristics of Ti, like low strain ability, and high reactivity, which lead to low compressibility. Moreover, Ti powders with small particle size are difficult to process by conventional PM techniques as they present a lower compressibility and also a poor flowability. On the other hand, the colloidal processing has been used for long in ceramics to achieve green bodies with high densities, complex shapes and homogeneous microstructures, but they are rarely used to shape metal powders because of its high density and high surface reactivity. However, the possibility to process fine particles makes these techniques interesting for metals with low density like Ti.The colloid-chemistry control of metallic powders in aqueous slurries is proposed as a way to prepare Ti porous parts with small particle size, throughout the formulation of aqueous slurries with solid contents as high as 50 vol.%. The chemical and chemical-physic stability of Ti powders 10 μm in size was determined by measuring the zeta potential as a function of pH, and dispersant concentration, while the later optimization of Ti slurries and their adequation for the use of different colloidal techniques, were studied in terms of rheology and the addition of the processing additives, such as gel or foaming agents. Techniques such as thermal gelling, foaming, and impregnation of exo-templates or robocasting were used to build Ti parts with random and/or tailored macroporosity. The shaped pieces made on Ti were sintered in vacuum at 1100 oC for 30 minutes, and their microstructure and mechanical properties were determined and compared with dense materials shaped by combining PM and colloidal techniques in previous works

A cheap and efficient catalyst with ultra-high activity for reduction of 4-nitrophenol

CrystEngComm ◽  
2015 ◽  
Vol 17 (30) ◽  
pp. 5744-5750 ◽  
Author(s):  
Weicheng Pan ◽  
Shenghuan Zhang ◽  
Fei He ◽  
Shili Gai ◽  
Yanbo Sun ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Particle Size ◽  
Catalytic Activity ◽  
Small Particle ◽  
Ni Nanoparticles ◽  
Small Particle Size ◽  
Efficient Catalyst ◽  
Nitrophenol Reduction ◽  
Loading Amount

Ni/SBA-15 catalyst with ultra-small particle size (7 nm), good dispersion, and ultra-high loading amount (57.4%) of Ni nanoparticles was prepared by a unique in situ thermal decomposition and reduction route. It exhibits excellent catalytic activity and stability for 4-nitrophenol reduction.

Dose schedule of Rasa Aushadhis

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Dr. Jambla Neha ◽  
Saroch Vikas ◽  
Johar Smita
Keyword(s):  
Particle Size ◽  
Oral Mucosa ◽  
Small Particle ◽  
Dose Schedule ◽  
The Body ◽  
Small Particle Size ◽  
Inherent Property ◽  
Ayurvedic Drugs ◽  
Modern Era

Rasashastra deals with the Rasa Aushadhis, the drugs of metallic and mineral origin. Mercury is used in most of the Rasaaushadhis. The toxicity of Mineral and metallic preparations are reduced to such an extent by various procedures of Shodhana, Marana etc. that Mercury converts its inherent property of toxicity into medicinal property. Rasa Aushadhis works quickly on the body because due to their small particle size, their absorption starts from the oral mucosa itself. The action of drugs depends largely upon the Anupana i.e. the vehicle for the drug. Rasacharayas have mentioned various Rasa preparations like Bhasmas, Parpati, Pottali, Manduras, Karpooras etc. along with their doses, dose schedule and Anupana / Sahapana etc. The principles of Rasaaushadhis when correlated in modern era are found to be scientifically accurate. We may say that Rasacharyas had already mastered the science of nanotechnology, purification, action of metabolic catalysts, biotransformation and preservation of medicines. The Ayurvedic drugs can be harmful for our body when not administered in proper dosage as per mentioned in classic literatures.

scholarly journals Flower-Shaped C-Dots/Co3O4{111} Constructed with Dual-Reaction Centers for Enhancement of Fenton-Like Reaction Activity and Peroxymonosulfate Conversion to Sulfate Radical

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 135
Author(s):  
Zhibin Wen ◽  
Qianqian Zhu ◽  
Jiali Zhou ◽  
Shudi Zhao ◽  
Jinnan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Centers ◽  
Organic Radicals ◽  
The Other ◽  
High Catalytic Activity ◽  
High Adsorption ◽  
High Turnover

Novel flower-shaped C-dots/Co3O4{111} with dual-reaction centers were constructed to improve the Fenton-like reaction activity and peroxymonosulfate (PMS) conversion to sulfate radicals. Due to the exposure of a high surface area and Co3O4{111} facets, flower-shaped C-dots/Co3O4{111} could provide more Co(II) for PMS activation than traditional spherical Co3O4{110}. Meanwhile, PMS was preferred for adsorption on Co3O4{111} facets because of a high adsorption energy and thereby facilitated the electron transfer from Co(II) to PMS. More importantly, the Co–O–C linkage between C-dots and Co3O4{111} induced the formation of the dual-reaction center, which promoted the production of reactive organic radicals (R•). PMS could be directly reduced to SO4−• by R• over C-dots. On the other hand, electron transferred from R• to Co via Co–O–C linkage could accelerate the redox of Co(II)/(III), avoiding the invalid decomposition of PMS. Thus, C-dots doped on Co3O4{111} improved the PMS conversion rate to SO4−• over the single active site, resulting in high turnover numbers (TONs). In addition, TPR analysis indicated that the optimal content of C-dots doped on Co3O4{111} is 2.5%. More than 99% of antibiotics and dyes were degraded over C-dots/Co3O4{111} within 10 min. Even after six cycles, C-dots/Co3O4{111} still remained a high catalytic activity.

scholarly journals Design and characterization of oil-in-water nanoemulsion for enhanced oil recovery stabilized by amphiphilic copolymer, nonionic surfactant, and LAPONITE® RD

RSC Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1952-1959
Author(s):  
Yi Zhao ◽  
Fangfang Peng ◽  
Yangchuan Ke
Keyword(s):  
Particle Size ◽  
Nonionic Surfactant ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Small Particle ◽  
Amphiphilic Copolymer ◽  
Good Stability ◽  
Small Particle Size ◽  
Oil In Water

Emulsion with small particle size and good stability stabilized by emulsifiers was successfully prepared for EOR application.

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