scholarly journals Copper(ii)-containing tungstotellurates(vi): syntheses, structures and their catalytic performances in selective oxidation of thioethers

RSC Advances ◽  
2020 ◽  
Vol 10 (38) ◽  
pp. 22515-22521
Author(s):  
Xuanyao Li ◽  
Peihe Li ◽  
Jinghai Liu ◽  
Zhengguo Lin ◽  
Changwen Hu
Keyword(s):  
Catalytic Activity ◽  
Selective Oxidation ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Very High ◽  
Catalytic Performances

Two copper(ii)-containing tungstotellurates(vi) were synthesized and present very high catalytic activity for the selective oxidation of thioethers under ambient conditions.

Ordered Intermetallic Nanoparticles with High Catalytic Activity Prepared by an Electrochemically Induced Phase Transformation

2019 ◽  
Author(s):  
Du Sun ◽  
yunfei wang ◽  
Kenneth Livi ◽  
chuhong wang ◽  
ruichun luo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Diffusion Mechanism ◽  
Reduction Reaction ◽  
Atomic Scale ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Magnetic Devices ◽  
Disordered Alloys ◽  
Ordered Intermetallic ◽  
Intermetallic Nanoparticles

<div> <p>The synthesis of alloys with long range atomic scale ordering (ordered intermetallics) is an emerging field of nanochemistry. Ordered intermetallic nanoparticles are useful for a wide variety of applications such as catalysis, superconductors, and magnetic devices. However, the preparation of nanostructured ordered intermetallics is challenging in comparison to disordered alloys, hindering progress in materials development. We report a process for converting colloidally synthesized ordered intermetallic PdBi<sub>2</sub> to ordered intermetallic Pd<sub>3</sub>Bi nanoparticles under ambient conditions by an electrochemically induced phase transition. The low melting point of PdBi<sub>2</sub> corresponds to low vacancy formation energies which enables the facile removal of the Bi from the surface, while simultaneously enabling interdiffusion of the constituent atoms via a vacancy diffusion mechanism under ambient conditions. The resulting phase-converted ordered intermetallic Pd<sub>3</sub>Bi exhibits 11x and 3.5x higher mass activty and high methanol tolerance for the oxygen reduction reaction compared to Pt/C and Pd/C, respectively,which is the highest reported for a Pd-based catalyst, to the best of our knowledge. These results establish a key development in the synthesis of noble metal rich ordered intermetallic phases with high catalytic activity, and sets forth guidelines for the design of ordered intermetallic compounds under ambient conditions.</p> </div>

PtAu alloy nanoparticles supported on thermally expanded graphene oxide as a catalyst for the selective oxidation of glycerol

RSC Advances ◽  
2015 ◽  
Vol 5 (47) ◽  
pp. 37112-37118 ◽  
Author(s):  
Gao-Yuan Yang ◽  
Shuai Shao ◽  
Yi-Hu Ke ◽  
Chun-Ling Liu ◽  
Hui-Fang Ren ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Catalytic Activity ◽  
Selective Oxidation ◽  
High Catalytic Activity ◽  
Alloy Nanoparticles

Thermally expanded graphene oxide supported PtAu alloy nanoparticles showed high catalytic activity in the oxidation of glycerol in base-free aqueous solution.

Rapid and large-scale synthesis of Co3O4 octahedron particles with very high catalytic activity, good supercapacitance and unique magnetic properties

RSC Advances ◽  
2015 ◽  
Vol 5 (127) ◽  
pp. 104991-105002 ◽  
Author(s):  
Mahabubur Chowdhury ◽  
Oghenochuko Oputu ◽  
Mesfin Kebede ◽  
Franscious Cummings ◽  
Oscar Cespedes ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Catalytic Activity ◽  
Large Scale ◽  
High Catalytic Activity ◽  
Large Scale Synthesis ◽  
Very High

Octahedron Co3O4 particles with very high catalytic activity, good supercapacitance, and unique magnetic properties.

Effect of an Oxides Composite Support of Ce(Sm)O3-La(Sr)CrO3 on Pd-Ni Alloy for Decomposition Activity of CH4

2010 ◽  
Vol 65 ◽  
pp. 215-224
Author(s):  
Ichiro Yamanaka ◽  
Yuta Nabae ◽  
Takeo Ito
Keyword(s):  
Catalytic Activity ◽  
Spherical Shape ◽  
Open Circuit ◽  
Fiber Formation ◽  
Oxidation Catalysis ◽  
High Catalytic Activity ◽  
Composite Anode ◽  
Composite Support ◽  
Ni Alloy ◽  
Very High

A Pd-Ni/La(Sr)CrO3-Ce(Sm)O2 composite anode showed good performance for solid oxide fuel cell reactions with dry CH4. Compositions of Pd and Ni in the Pd-Ni/La(Sr)CrO3-Ce(Sm)O2 composite anode affected the electrochemical oxidation catalysis of dry CH4. The Pd and Ni ratios from 50:50 to 75:25 were suitable for the oxidation. The Pd-Ni/La(Sr)CrO3-Ce(Sm)O2 composite anode showed the high tolerance to the carbon deposition under closed and open circuit conditions. A Pd-Ni/Ce(Sm)O2 catalyst showed very low catalytic activity for decomposition of dry CH4. A Pd-Ni/SiO2 catalyst showed very high catalytic activity for the decomposition of dry CH4 and a large amount of deposited carbon formed. The Pd-Ni particles on SiO2 were quite multifaceted from TEM-EDS observation. On the other hand, the Pd-Ni particles on Ce(Sm)O2 support had a spherical shape and doping of Ce and Sm was confirmed. This nature should inhibit the formation of particular plane that is essential for the carbon fiber formation. The detail function of Ce(Sm)O2 and La(Sr)CrO3 supports was discussed.

scholarly journals Single-walled carbon nanotube supported Pt-Ru bimetallic superb nanocatalyst for the hydrogen generation from the methanolysis of methylamine-borane at mild conditions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Eda Gokirmak Sogut ◽  
Hilal Acidereli ◽  
Esra Kuyuldar ◽  
Yasar Karatas ◽  
Mehmet Gulcan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Carbon Nanotube ◽  
Hydrogen Generation ◽  
Catalyst System ◽  
Metal Nanoparticle ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Different Temperatures

Abstract Several metal nanoparticle based catalysts have been synthesized for catalyzing the hydrogen production process by hydrolysis of methylamine-borane (MeAB). However, there was only one study that catalyzes the producing of hydrogenvia the methanolysis of MeAB, and it was carried out by our research group. For this reason, in this work, a new catalyst system entitled by single-walled carbon nanotube (SWCNT) supported bimetallic platinum-ruthenium nanoparticles were developed and called as PtRu@SWCNT. These NPs were characterized by several techniques (XRD, XPS, Raman, and TEM), and they were performed for the methanolysis of MeAB with high catalytic activity. The prepared PtRu@SWCNT NPs were also tested in the methanolysis of MeAB at different parameters including different temperatures, catalyst and substrate concentrations, and reusability performance. Experimental results revealed that the new PtRu@SWCNT NPs had excellent catalytic activity and reusability for removing of hydrogen from the methanolysis of MeAB at ambient conditions. According to the obtained data, the turnover frequency is 136.25 mole H2/mole PtRu × min, and the activation energy (Ea) is 17.29 kJ/mole. More than 99% of conversion was observed at room temperature.

scholarly journals Application of Nanotechnology in Post-treatment of Automobile Tail Gas Nitrogen Oxides

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Xie Yansheng
Keyword(s):  
Catalytic Activity ◽  
High Catalytic Activity ◽  
Good Prospect ◽  
Exhaust Gas ◽  
Automobile Exhaust ◽  
Existing Problems ◽  
Catalytic Materials ◽  
Nano Catalyst ◽  
And Performance ◽  
Very High

Nano-catalyst has a very high catalytic activity and has a good prospect in automobile exhaust gas purifi cation. Thispaper summarizes the research status of nano-scale automobile exhaust gas purifi cation catalytic materials in recentyears, focusing on the analysis of the structure and performance of several components in the tail gas catalyst afternano-scale, and discusses its existing problems and application trends.

An Innovative Synthesis of Spinel-Structured and Ferromagnetic Behaviour of Fe3O4 Nanoparticles Antibacterial and Catalytic Activity Evaluated in the Selective Oxidation

2020 ◽  
Vol 18 (3) ◽  
pp. 236-240
Author(s):  
S. Ambika ◽  
K. Saravanan
Keyword(s):  
Antimicrobial Activity ◽  
Catalytic Activity ◽  
Selective Oxidation ◽  
Fe3o4 Nanoparticles ◽  
Ferromagnetic Behaviour ◽  
Combustion Route ◽  
First Time ◽  
Catalytic Performances

Nanocrystalline Fe3O4 powder was produced via the organic combustion route using L-arginine for the first time as fuel. The prepared yields is considered through several investigates, such as, DRS, PL, XRD, SEM, TEM, EDS, and VSM. The current study existence limited only toward the antimicrobial activity that the limit Fe3O4. The influences for catalytic performances were explained in factor, while the samples characterization was presented.

LDH-derived catalysts for complete oxidation of volatile organic compounds

Clay Minerals ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 67-77 ◽  
Author(s):  
K. Bahranowski ◽  
E. Bielańska ◽  
R. Janik ◽  
T. Machej ◽  
E. M. Serwicka
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxide ◽  
Copper Chromite ◽  
Oxide System ◽  
High Catalytic Activity ◽  
Commercial Catalyst ◽  
Volatile Organic ◽  
Double Hydroxides ◽  
Very High

AbstractThe Cu,Cr-, Zn,Cr- and Cu,Al-layered double hydroxides have been synthesized by the coprecipitation method and characterized by elemental analysis, PXRD, SEM/EDS and BET. The mixed oxide materials obtained upon calcination at 873 K show very high catalytic activity for the combustion of toluene and ethanol. The best sample is derived from the Cu,Cr-LDH precursor with a Cu:Cr ratio of 2, composed of copper oxide and copper chromite. This catalyst gave 50% conversion of toluene and ethanol at temperatures of 45 and 15 K lower, respectively, than the reference commercial catalyst. Catalytic tests with a mechanical mixture of CuO and CuCr2O4 demonstrate that the use of an LDH precursor is essential for optimum results. The importance of the simultaneous presence of both Cu and Cr, the influence of the Cu:Cr ratio on the catalytic activity and the role of the interface boundaries in the CuO-CuCr2O4 mixed oxide system are discussed.

In situ Synthesis of Reduced Graphene Oxide Supported CoMo Nanoparticles as Efficient Catalysts for Hydrogen Generation from NH3BH3

2018 ◽  
Vol 232 (3) ◽  
pp. 431-443 ◽  
Author(s):  
Xigang Du ◽  
Yonghua Duan ◽  
Jun Zhang ◽  
Gang Mi
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Catalytic Activity ◽  
Reduced Graphene Oxide ◽  
Hydrogen Generation ◽  
Sodium Molybdate ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Reduced Graphene

AbstractCoMo nanoparticles (NPs) supported on reduced graphene oxide (RGO) were synthesized by a one-stepin situco-reduction of an aqueous solution of cobalt(II) chloride, sodium molybdate dihydrate and graphene oxide (GO) using NaBH4as the sole reductant under ambient conditions. The powder XRD, FTIR, EDS and TEM were employed to characterize the structure, size and composition of the CoMo/RGO catalysts. The as-synthesized Co0.9Mo0.1/RGO catalysts exhibited high catalytic activity for the hydrolytic dehydrogenation of ammonia borane (AB) at room temperature. The as-synthesized Co0.9Mo0.1/RGO nanocatalysts exhibited much higher catalytic activity than Co/RGO, Mo/RGO and the RGO-free Co0.9Mo0.1counterpart. Moreover, kinetic studies indicate that the catalytic hydrolysis of AB by Co0.9Mo0.1/RGO has first order kinetics with respect to the the catalyst concentration, but zero order kinetics with respect to the substrate concentration. The Co0.9Mo0.1/RGO catalyst has a turnover frequency (TOF) of 15.8 mol H2·(mol·Co0.9Mo0.1/RGO)−1·min−1at 25°C. Furthermore, the Co0.9Mo0.1/RGO show good recyclability for hydrogen generation from an aqueous solution of AB, which enables the practical reuse of the catalysts. Hence, this general method can be easily extended to the facile preparation of other RGO-based metallic systems.

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