Valence variation of phase-pure M1 MoVNbTe oxide by plasma treatment for improved catalytic performance in oxidative dehydrogenation of ethane

RSC Advances ◽  
2015 ◽  
Vol 5 (111) ◽  
pp. 91295-91301 ◽  
Author(s):  
Xin Chen ◽  
Qianli Yang ◽  
Bozhao Chu ◽  
Hang An ◽  
Yi Cheng

This work presents a new method of catalyst surface modification by using oxygen plasma to change the oxidation state of active sites in metal oxide catalysts.

Author(s):  
Aline Villarreal ◽  
Gabriella Garbarino ◽  
Paola Riani ◽  
Aida Gutiérrez Alejandre ◽  
Jorge Ramírez ◽  
...  

The influence of incorporating a small amount of silica on the catalytic performance of MoO3/Al2O3 catalyst was studied. Molybdenum supported on pure alumina and 5% SiO2-Al2O3 supports were synthesized. The catalysts were characterized by XRD, Raman, UV-Vis and IR spectroscopies, FE-SEM microscopy, and their activity was evaluated in the oxidative dehydrogenation of ethanol to acetaldehyde. Molybdenum supported on pure alumina gives a 74% yield to acetaldehyde (at 573 K) due to the generation of oxy-dehydrogenation active sites by molybdenum and to the decrement of the alumina dehydration sites. For the molybdenum catalyst supported on silica-containing alumina, the molybdenum species were displaced from the strongest alumina’s acid-base couples, located on nanoparticles edges, corners and defects, to weaker ones located on plane faces causing the rise of weakly bonded species with less active redox behavior.  


2017 ◽  
Vol 53 ◽  
pp. 450-459 ◽  
Author(s):  
Abdulrahman Baki ◽  
Cheryl V. Rahman ◽  
Lisa J. White ◽  
David J. Scurr ◽  
Omar Qutachi ◽  
...  

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Abolfazl Mozaffari ◽  
Mazeyar Parvinzadeh Gashti ◽  
Mohammad Mirjalili ◽  
Masoud Parsania

In the present study, we developed a novel approach for functionalization of gelatin nanofibers using the plasma method for tissue engineering applications. For this purpose, tannic acid-crosslinked gelatin nanofibers were fabricated with electrospinning, followed by treatment with argon and argon–oxygen plasmas in a vacuum chamber. Samples were evaluated by using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, contact angle (CA) and X-ray diffraction (XRD). The biological activity of plasma treated gelatin nanofibers were further investigated by using fibroblasts as cell models. SEM studies showed that the average diameter and the surface morphology of nanofibers did not change after plasma treatment. However, the mean surface roughness (RMS) of samples were increased due to plasma activation. ATR-FTIR spectroscopy demonstrated several new bands on plasma treated fibers related to the plasma ionization of nanofibers. The CA test results stated that the surface of nanofibers became completely hydrophilic after argon–oxygen plasma treatment. Finally, increasing the polarity of crosslinked gelatin after plasma treatment resulted in an increase of the number of fibroblast cells. Overall, results expressed that our developed method could open new insights into the application of the plasma process for functionalization of biomedical scaffolds. Moreover, the cooperative interplay between gelatin biomaterials and argon/argon–oxygen plasmas discovered a key composition showing promising biocompatibility towards biological cells. Therefore, we strongly recommend plasma surface modification of nanofiber scaffolds as a pretreatment process for tissue engineering applications.


Author(s):  
Yuji Kikukawa ◽  
Yui Sakamoto ◽  
Hikari Hirasawa ◽  
Yushi Kurimoto ◽  
Hiroya Iwai ◽  
...  

Elucidation of the correlation between the catalytic performance and the structures of active sites on inorganic materials provides insights into the chemistry of the local structures on metal oxide catalysts....


Author(s):  
Dan Dang ◽  
Yuxin Chen ◽  
Xin Chen ◽  
Kai Feng ◽  
Binhang Yan ◽  
...  

The catalytic performance of the phase-pure M1 MoVNbTeOx catalyst is enhanced by introducing TiO2 in oxidative dehydrogenation of ethane (ODHE). The space-time yield (STY) of the M1/TiO2 composite catalyst increases...


2015 ◽  
Vol 595 ◽  
pp. 164-170 ◽  
Author(s):  
S. Alwin ◽  
X. Sahaya Shajan ◽  
Ranjini Menon ◽  
P.Y. Nabhiraj ◽  
K.G.K. Warrier ◽  
...  

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