Low-temperature catalytic decomposition of N2O on platinum and bismuth-modified platinum: identification of active sites

2002 ◽  
pp. 2738-2739 ◽  
Author(s):  
R. Burch ◽  
G. A. Attard ◽  
S. T. Daniells ◽  
D. J. Jenkins ◽  
J. P. Breen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Active Sites ◽  
Catalytic Decomposition

Low-Temperature Diffusion of Transition Metals at the Presence of Radiation Defects in Silicon

2011 ◽  
Vol 178-179 ◽  
pp. 421-426
Author(s):  
Jan Vobecký ◽  
Volodymyr Komarnitskyy ◽  
Vít Záhlava ◽  
Pavel Hazdra
Keyword(s):  
Low Temperature ◽  
Active Sites ◽  
Carrier Lifetime ◽  
High Energy ◽  
Deep Levels ◽  
Radiation Defects ◽  
Metal Atoms ◽  
Temperature Diffusion ◽  
Concentration Enhancement ◽  
Application Potential

Low-temperature diffusion of Cr, Mo, Ni, Pd, Pt, and V in silicon diodes is compared in the range 450 - 800 oC. Before the diffusion, the diodes were implanted with high-energy He2+ to assess, if the radiation defects enhance the concentration of metal atoms at electrically active sites and what is the application potential for carrier lifetime control. The devices were characterized using AES, XPS, DLTS, OCVD carrier lifetime and diode electrical parameters. The metal atoms are divided into two groups. The Pt, Pd and V form deep levels in increased extent at the presence of radiation defects above 600 oC, which reduces the excess carrier lifetime. It is shown as a special case that the co-diffusion of Ni and V from a NiV surface layer results fully in the concentration enhancement of the V atoms. The enhancement of the acceptor level V-/0 (EC 0.203 eV) and donor level V0/+ (EC 0.442 eV) resembles the behavior of substitutional Pts. The second group is represented by the Mo and Cr. They easily form oxides, which can make their diffusion into a bulk more difficult or impossible. Only a slight enhancement of the Cr-related deep levels by the radiation defects has been found above 700 oC.

scholarly journals Production of COx-Free Hydrogen and Few-Layer Graphene Nanoplatelets by Catalytic Decomposition of Methane over Ni-Lignin-Derived Nanoparticles

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 503
Author(s):  
Qiangu Yan ◽  
Timothy Ketelboeter ◽  
Zhiyong Cai
Keyword(s):  
Active Sites ◽  
Nickel Nanoparticles ◽  
Catalytic Decomposition ◽  
Graphene Nanoplatelets ◽  
Methane Decomposition ◽  
High Catalytic Activity ◽  
Layer Graphene ◽  
Free Hydrogen ◽  
Decomposition Of Methane ◽  
Few Layer Graphene

Nickel (Ni)-lignin nanocomposites were synthesized from nickel nitrate and kraft lignin then catalytically graphitized to few-layer graphene-encapsulated nickel nanoparticles (Ni@G). Ni@G nanoparticles were used for catalytic decomposition of methane (CDM) to produce COx-free hydrogen and graphene nanoplatelets. Ni@G showed high catalytic activity for methane decomposition at temperatures of 800 to 900 °C and exhibited long-term stability of 600 min time-on-stream (TOS) without apparent deactivation. The catalytic stability may be attributed to the nickel dispersion in the Ni@G sample. During the CDM reaction process, graphene shells over Ni@G nanoparticles were cracked and peeled off the nickel cores at high temperature. Both the exposed nickel nanoparticles and the cracked graphene shells may participate the CDM reaction, making Ni@G samples highly active for CDM reaction. The vacancy defects and edges in the cracked graphene shells serve as the active sites for methane decomposition. The edges are continuously regenerated by methane molecules through CDM reaction.

scholarly journals CO Oxidation over Metal Oxide (La2O3, Fe2O3, PrO2, Sm2O3, and MnO2) Doped CuO-Based Catalysts Supported on Mesoporous Ce0.8Zr0.2O2 with Intensified Low-Temperature Activity

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 724 ◽  
Author(s):  
Yan Cui ◽  
Leilei Xu ◽  
Mindong Chen ◽  
Chufei Lv ◽  
Xinbo Lian ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Co Oxidation ◽  
Active Sites ◽  
Earth Metal ◽  
High Dispersion ◽  
Impregnation Method ◽  
X Ray

CuO-based catalysts are usually used for CO oxidation owing to their low cost and excellent catalytic activities. In this study, a series of metal oxide (La2O3, Fe2O3, PrO2, Sm2O3, and MnO2)-doped CuO-based catalysts with mesoporous Ce0.8Zr0.2O2 support were simply prepared by the incipient impregnation method and used directly as catalysts for CO catalytic oxidation. These mesoporous catalysts were systematically characterized by X-ray powder diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), energy-dispersed spectroscopy (EDS) mapping, X-ray photoelectron spectroscopy (XPS), and H2 temperature programmed reduction (H2-TPR). It was found that the CuO and the dopants were highly dispersed among the mesoporous framework via the incipient impregnation method, and the strong metal framework interaction had been formed. The effects of the types of the dopants and the loading amounts of the dopants on the low-temperature catalytic performances were carefully studied. It was concluded that doped transition metal oxides could regulate the oxygen mobility and reduction ability of catalysts, further improving the catalytic activity. It was also found that the high dispersion of rare earth metal oxides (PrO2, Sm2O3) was able to prevent the thermal sintering and aggregation of CuO-based catalysts during the process of calcination. In addition, their presence also evidently improved the reducibility and significantly reduced the particle size of the CuO active sites for CO oxidation. The results demonstrated that the 15CuO-3Fe2O3/M-Ce80Zr20 catalyst with 3 wt. % of Fe2O3 showed the best low-temperature catalytic activity toward CO oxidation. Overall, the present Fe2O3-doped CuO-based catalysts with mesoporous nanocrystalline Ce0.8Zr0.2O2 solid solution as support were considered a promising series of catalysts for low-temperature CO oxidation.

Exposed ternary metal active sites on mesoporous channels: A promising catalyst for low-temperature selective catalytic oxidization of phenol with H2O2

2019 ◽  
Vol 478 ◽  
pp. 110568 ◽  
Author(s):  
Shuying Gao ◽  
Fu Yang ◽  
Xianfeng Liu ◽  
Xu Hu ◽  
Changjian Song ◽  
...  
Keyword(s):  
Low Temperature ◽  
Active Sites ◽  
Ternary Metal ◽  
Catalytic Oxidization

Low Temperature Nitridatio of SiO2 Films using a Catalytic-CVD System

2000 ◽  
Vol 611 ◽  
Author(s):  
Akira Izumi ◽  
Hidekazu Sato ◽  
Hideki Matsumura
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Silicon Dioxide ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Catalytic Decomposition ◽  
Catalytic Chemical Vapor Deposition ◽  
Sio2 Films ◽  
X Ray

ABSTRACTThis paper reports a procedure for low-temperature nitridation of silicon dioxide (SiO2) surfaces using species produced by catalytic decomposition of NH3 on heated tungsten in catalytic chemical vapor deposition (Cat-CVD) system. The surface of SiO2/Si(100) was nitrided at temperatures as low as 200°C. X-ray photoelectron spectroscopy measurements revealed that incorporated N atoms are bound to Si atoms and O atoms and located top-surface of SiO2.

Identification of active sites and reaction mechanism on low-temperature SCR activity over Cu-SSZ-13 catalysts prepared by different methods

2016 ◽  
Vol 6 (16) ◽  
pp. 6294-6304 ◽  
Author(s):  
Tao Zhang ◽  
Feng Qiu ◽  
Huazhen Chang ◽  
Xiang Li ◽  
Junhua Li
Keyword(s):  
Aqueous Solution ◽  
Reaction Mechanism ◽  
Low Temperature ◽  
Ion Exchange ◽  
Active Sites ◽  
One Pot ◽  
One Pot Synthesis ◽  
Low Temperature Scr

Cu-SSZ-13 catalysts with similar Si/Al and Cu/Al ratios were prepared by aqueous solution ion-exchange (Cu-SSZ-13-I) and one-pot synthesis (Cu-SSZ-13-O) methods.

Low-temperature CO oxidation on Ag/ZSM-5 catalysts: Influence of Si/Al ratio and redox pretreatments on formation of silver active sites

Fuel ◽  
2017 ◽  
Vol 188 ◽  
pp. 121-131 ◽  
Author(s):  
E. Kolobova ◽  
A. Pestryakov ◽  
G. Mamontov ◽  
Yu. Kotolevich ◽  
N. Bogdanchikova ◽  
...  
Keyword(s):  
Low Temperature ◽  
Co Oxidation ◽  
Active Sites ◽  
Low Temperature Co Oxidation
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