Molecular perspective of MoS2/Co unsupported catalyst using computer assisted TEM simulations

2012 ◽  
Vol 1373 ◽  
Author(s):  
Manuel Ramos ◽  
Joseph Serrano-Matos ◽  
Eduan Martinez-Soto ◽  
Brenda Torres ◽  
Gilles Berhault ◽  
...  

ABSTRACTUnderstanding the morphology of catalytically active materials has been approached successfully in past decades using field electron microscopy in scanning and transmission modes. In this respect, some simulated TEM measurements for unsupported promoted molybdenum di-sulfide (MoS2/Co) provided some insights about molecular structure in those catalytic layered transition metal sulfides (LTMS). However, due to poor resolution, lack of color enhancement, and other factors, sections of those materials observed under TEM do not resolve the structure by itself; in particular about the localization of cobalt atoms for promoted MoS2 unsupported catalyst. This work concludes an epitaxial growth of MoS2 slabs over (111)-Co9S8 crystallographic plane, with a stacking degree size of 6 slabs. Results presented in here are obtained using experimental HRTEM and TEM simulations using the multi-slice method with a slice thickness of 25 Å and projected potential$f(U) = \sum\limits_{i = 1}^n {a_i e^{(- b_i U^2)} } $, where ai and bi are coefficients to be determined.

2013 ◽  
Vol 49 (7) ◽  
pp. 681-684 ◽  
Author(s):  
O. S. Khalipova ◽  
S. A. Kuznetsova ◽  
S. I. Galanov ◽  
V. V. Kozik

2009 ◽  
Vol 21 (4) ◽  
pp. 655-661 ◽  
Author(s):  
Felipe Gándara ◽  
Enrique Gutiérrez Puebla ◽  
Marta Iglesias ◽  
Davide M. Proserpio ◽  
Natalia Snejko ◽  
...  

2020 ◽  
Vol 56 (7) ◽  
pp. 765-769
Author(s):  
N. P. Shabel’skaya ◽  
E. A. Yatsenko ◽  
R. P. Medvedev ◽  
B. M. Gol’tsman ◽  
E. V. Vasil’eva ◽  
...  

2019 ◽  
Vol 63 (4) ◽  
pp. 265-276
Author(s):  
Cristina Estruch Bosch ◽  
Stephen Poulston ◽  
Paul Collier ◽  
Joris W. Thybaut ◽  
Guy B. Marin

Microemulsions were used to develop a catalyst with high selectivity towards ethylene and ethane while maintaining considerable methane (CH4) conversion. The use of this technique to produce lanthanum nanoparticles was studied under different conditions. Temperature was shown to have the most significant effect on the final material properties providing a minimum crystallite size at 25°C. The morphology observed for all the samples was flake or needle like materials containing nanocrystallites. To obtain the catalytically active materials a thermal treatment was needed and this was studied using in situ X-ray diffraction (XRD). This analysis demonstrated that the materials exhibited significant changes in phase and crystallite size when submitted to thermal treatment and these were shown to be difficult to control, meaning that the microemulsion synthesis method is a challenging route to produce La nanoparticles in a reproducible manner. The materials were tested for oxidative coupling of methane (OCM) and no correlation could be observed between the ‘as synthesised’ crystallite size and activity. However, the presence of La carbonates in the materials produced was deemed to be crucial to ensure an adequate OCM activity.


1980 ◽  
Vol 7 (1) ◽  
pp. 61-63 ◽  
Author(s):  
Nicholas J. Schneiders ◽  
Stewart C. Bushong

2020 ◽  
Vol 22 (2) ◽  
pp. 455-464 ◽  
Author(s):  
Joanna Kwiczak-Yiğitbaşı ◽  
Özge Laçin ◽  
Mine Demir ◽  
Recep Erdem Ahan ◽  
Urartu Özgür Şafak Şeker ◽  
...  

Mechanochemical production of cellulose–metal NP composites requires no capping or reducing agents, and yields antibacterial and catalytically active materials.


2015 ◽  
Vol 51 (74) ◽  
pp. 14026-14029 ◽  
Author(s):  
Faegheh Hoshyargar ◽  
Husnaa Khan ◽  
Kourosh Kalantar-zadeh ◽  
Anthony P. O'Mullane

A facile route to prepare catalytically active materials from a liquid metal alloy is introduced. Sonication of liquid galinstan (GaInSn) in alkaline solution or treating it with reducing agents generates In : Sn rich microspheres that are catalytically active for electron transfer reactions such as potassium ferricyanide and 4-nitrophenol reduction.


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