scholarly journals High-temperature heterogeneous catalysis in platinum nanoparticle – molten salt suspensions

2020 ◽  
Vol 10 (3) ◽  
pp. 625-629
Author(s):  
Behzad Tangeysh ◽  
Clarke Palmer ◽  
Horia Metiu ◽  
Michael J. Gordon ◽  
Eric W. McFarland

Suspensions of platinum nanoparticles (PtNPs) were formed in molten LiCl–LiBr–KBr via thermal decomposition of H2PtCl6, and subsequently evaluated for thermal stability and CO oxidation activity.

RSC Advances ◽  
2018 ◽  
Vol 8 (39) ◽  
pp. 21699-21711
Author(s):  
Yu Huanhuan ◽  
Chen Fayun ◽  
Zhubaolin Zhubaolin ◽  
Huang Weiping ◽  
Zhang Shoumin

A CePO4–GdPO4 composite was prepared by a general ultrasound method and could be a good support for gold nanocatalysts. Au/CePO4–GdPO4 catalysts with a low content of gold showed good catalytic activity, high temperature resistance and stability for CO oxidation.


2008 ◽  
Vol 32 (12) ◽  
pp. 1164-1174 ◽  
Author(s):  
Qiang Peng ◽  
Xiaolan Wei ◽  
Jing Ding ◽  
Jianping Yang ◽  
Xiaoxi Yang

2018 ◽  
Vol 8 (5) ◽  
pp. 1383-1394 ◽  
Author(s):  
Iljeong Heo ◽  
Steven J. Schmieg ◽  
Se H. Oh ◽  
Wei Li ◽  
Charles H. F. Peden ◽  
...  

CuO supported on a commercial mixed cerium–zirconium oxide shows remarkable improvement in CO oxidation after high temperature hydrothermal aging.


2011 ◽  
Vol 142 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Toshihiko Osaki ◽  
Kiho Yamada ◽  
Koji Watari ◽  
Koji Tajiri ◽  
Saori Shima ◽  
...  

2017 ◽  
Vol 7 (21) ◽  
pp. 5038-5048 ◽  
Author(s):  
Jinshi Dong ◽  
Jun Wang ◽  
Jianqiang Wang ◽  
Ming Yang ◽  
Wei Li ◽  
...  

Alumina with 5.0 μmol m−2 phosphorus additives could retain a higher Pd dispersion after aging, resulting in much higher CO oxidation activity.


2021 ◽  
Author(s):  
James Ewen ◽  
Carlos Ayestaran Latorre ◽  
Chiara Gattinoni ◽  
Arash Khajeh ◽  
Joshua Moore ◽  
...  

<p></p><p>Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. An atomic-level understanding of phosphate ester tribofilm formation mechanisms is required to improve their tribological performance. A process of particular interest is the thermal decomposition of phosphate esters on steel surfaces, since this initiates polyphosphate film formation. In this study, reactive force field (ReaxFF) molecular dynamics (MD) simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. The ReaxFF parameterisation was validated for a representative system using density functional theory (DFT) calculations. During the MD simulations on Fe 3 O 4 (001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature increases from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe 3 O 4 , most of the molecules are physisorbed and some desorption occurs at high temperature. Thermal decomposition rates were much higher on Fe 3 O 4 (001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe 3 O 4. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately polyphosphate film formation. For the alkyl phosphates, thermal decomposition proceeds mainly through CO and C-H cleavage on Fe 3 O 4 (001). Aryl phosphates show much higher thermal stability, and decomposition on Fe 3 O 4 (001) only occurs through P-O and C-H cleavage, which require very high temperature. The onset temperature for CO cleavage on Fe 3 O 4 (001) increases as: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is consistent with experimental observations for the thermal stability of antiwear additives with similar substituents. The simulation results clarify a range of surface and substituent effects on the thermal decomposition of phosphate esters on steel that should be helpful for the design of new molecules with improved tribological performance.<br></p><p></p>


Author(s):  
Mohit Mittal ◽  
Rajiv Chaudhary

Recently, most of the industries are looking towards to incorporate sustainable, renewable, eco- friendly and affordable raw materials and production process. To achieve this goal, engineers and technologist are working on biocomposite material. The primary reason behind the selection of natural fiber based material in the automobile, construction, and aerospace industry is its low cost, lightweight, high specific strength and modulus, biodegradability, and friendly processing. Inspite of all beneficial features, one of the main barriers to their utilization in all mentioned sectors is thermal degradability. Natural fibers can be subjected to thermal degradation during composite processing and their application in the high-temperature field. So it is practically significant to understand the thermal decomposition of lignocellulosic fibers and to modify it for the purpose of high-temperature stability. In this work, alkaline treatment of varying concentrations (2%, 4%, 6%, 8%, and 10 wt %) was used to study the effect of alkaline treatment on thermal stability of pineapple leaf fibers. The thermal behavior of untreated and alkali treated pineapple leaf fiber was examined by using a thermal gravimetric analysis instrument (TGA). The results show that 4 wt% NaOH treated pineapple leaf fiber have maximum thermal stability. The decomposition of untreated and treated PALF was a two-stage process attributed to the thermal decomposition of hemicellulose, cellulose, and lignin. The results also showed that the temperature of initial degradation 251 0C increased to 285 0C after 4% alkaline treatment due to partial removal of hemicellulose and lignin.


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