Synthesis, Surface Reactivity, and Catalytic Activity of High Specific Surface Area Molybdenum Nitride Powders

Author(s):  
L. Volpe ◽  
S.T. Oyama ◽  
M. Boudart
2021 ◽  
Vol 1036 ◽  
pp. 130-136
Author(s):  
Ting Qun Tan ◽  
Lei Geng ◽  
Yan Lin ◽  
Yan He

In order to prepare carbon nanotubes with high specific surface area, small diameter, low resistivity, high purity and high catalytic activity, the Fe-Mo/Al2O3 catalyst was prepared based on the microreactor. The influence of different Fe/Al molar ratios on the catalyst and the carbon nanotubes prepared was studied through BET, SEM, TEM and other detection methods. Studies have shown that the pore structure of the catalyst is dominated by slit pores at a lower Fe/Al molar ratio. The catalytic activity is the highest when the Fe/Al molar ratio is 1:1, reaching 74.1%. When the Fe/Al molar ratio is 1:2, the catalyst has a higher specific surface area, the maximum pore size is 8.63 nm, and the four-probe resistivity and ash content of the corresponding carbon nanotubes are the lowest. The higher the proportion of aluminum, the higher the specific surface area of the catalyst and the carbon nanotubes, and the finer the diameter of the carbon nanotubes, which gradually tends to relax. The results show that when the Fe/Al molar ratio is 1:2, although the catalytic activity of the catalyst is not the highest, the carbon nanotubes prepared have the best performance.


2007 ◽  
Vol 361-363 ◽  
pp. 809-812 ◽  
Author(s):  
C. Azevedo ◽  
B. Tavernier ◽  
Jean Louis Vignes ◽  
Pierre Cenedese ◽  
Pierre Dubot

Recent studies showed that the particle size of fillers, using for the reinforcement of dental resin composites, should be as small as possible to provide the maximum surface area for bonding to resin monomer, and should be kept well dispersed so as to be functionalized by a silane. In the present study, porous alumina monoliths with high specific surface area, measured by the Brunauer-Emmett-Teller (B.E.T.) method, were obtained using a novel preparation method. Structure and surface reactivity have been investigated as functions of temperature and chemical treatments. The impregnation of the as-prepared material by Triméthyletoxysilane (TMES) stabilized alumina with high specific surface area at higher temperature. A FTIR study has described the effect of TMES treatment and temperature on the structure of the material. The use of allyldimethoxysilane (ADMS) as a probe molecule for measuring the surface reactivity, has allowed us to show that the treatment of samples with TMES and their reheating at 1300°C results in adsorption sites which give stronger chemical bonds. This preliminary study has, therefore, allowed us to optimize the structural and surface treatment of experimental fillers before their use in the reinforcement of resin composites or resin-modified glass-ionomer cements.


2018 ◽  
Vol 6 (20) ◽  
pp. 9716-9722 ◽  
Author(s):  
Ya-Nan Chen ◽  
Yibo Guo ◽  
Huijuan Cui ◽  
Zhaojun Xie ◽  
Xin Zhang ◽  
...  

MnO@Co–N/C composites were fabricated with excellent bifunctional catalytic activity and outstanding performance for both liquid- and solid-state Zn–air batteries. The excellent electrocatalytic activities are attributed to the unique 1D nanowire structure with abundant Co–Nx active sites and a high specific surface area.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.


2021 ◽  
Vol 45 (12) ◽  
pp. 5712-5719
Author(s):  
Yongxiang Zhang ◽  
Peifeng Yu ◽  
Mingtao Zheng ◽  
Yong Xiao ◽  
Hang Hu ◽  
...  

Porous carbons with a high specific surface area (2314–3470 m2 g−1) are prepared via a novel KCl-assisted activation strategy for high-performance supercapacitor.


2021 ◽  
Vol 319 ◽  
pp. 111063
Author(s):  
Yury M. Volfkovich ◽  
Valentin E. Sosenkin ◽  
Alexei Y. Rychagov ◽  
Alexandr V. Melezhik ◽  
Alexei G. Tkachev ◽  
...  

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