Results 191 to 200 of about 9,159 (244)

Ruthenium–Niobia Interaction in Nb2O5-Supported and Nb2O5-Modified Ru Catalysts

Bulletin of the Chemical Society of Japan, 1994
Abstract The effect of H2 reduction treatments on H2 chemisorption, ethane hydrogenolysis, and CO hydrogenation over Nb2O5-supported and Nb2O5-modified Ru catalysts has been studied to elucidate the nature of the metal-oxide interaction, and the results are compared with those of a SiO2-supported Ru catalyst.
Kimio Kunimori, Hisakazu Shindo, Daisuke Nishio, Takeshi Sugiyama, Toshio Uchijima   +4 more
openaire   +1 more source

Interaction of pyridine on Nb2O5

Journal of Molecular Structure: THEOCHEM, 2005
Abstract We have studied the interaction of pyridine on oxide surface in order to characterize the Lewis acid sites. Ab initio RHF method was employed at 3-21G* all electron basis set level. The LanL2DZ effective core potential was also used and compared with all electron basis set results.
João B.L. Martins, Tiago A.S. Fialho
openaire   +1 more source

Activity and acidity of Nb2O5-MoO3 and Nb2O5-WO3 in the Friedel-Crafts alkylation

Catalysis Today, 2006
Abstract Nb2O5 loaded on the supports and mixed with oxides was studied to investigate the activity and acidity for Friedel-Crafts benzylation of anisole. From the study on the loaded catalysts, a preliminary conclusion for the selection of metal oxide was obtained; namely, such an acidic oxide as silica was suitable for the support of Nb2O5.
K YAMASHITA, M HIRANO, K OKUMURA, M NIWA
openaire   +1 more source

Catalytic cracking of polystyrene pyrolysis oil: Effect of Nb2O5 and NiO/Nb2O5 catalyst on the liquid product composition

Waste Management, 2022
The catalytic cracking of polystyrene pyrolysis oil was investigated over a Nb2O5 and a NiO/Nb2O5 catalyst in a fixed bed reactor. First, the pyrolysis of two different polystyrene feedstock (polystyrene foam and polystyrene pellet) was carried out in a semi-batch reactor, and the resulting polystyrene pellets pyrolysis oil was selected for catalytic ...
Um-E-Salma, Amjad, Arshia, Tajjamal, Anwar, Ul-Hamid, Abrar, Faisal, Syed Ammar Hussain, Zaidi, Lubna, Sherin, Amna, Mir, Maria, Mustafa, Nabeel, Ahmad, Murid, Hussain, Young-Kwon, Park   +10 more
openaire   +2 more sources

Use of Nb2O5 as nickel passivating agent: characterisation of the Ni/Nb2O5/SiO2 system

Catalysis Today, 2003
Abstract Niobia-modified silica was used as support for nickel-based catalysts. Catalysts with different nickel loading were prepared by successive incipient-wetness impregnation of toluenic nickel octanoate solutions. The samples were characterised after both calcination and reduction by TEM-EDX techniques and tested in the ethane hydrogenolysis ...
Luciana T. Santos, Evandro B. Pereira, Narcís Homs, Jordi Llorca, Pilar Ramírez de la Piscina, Marcelo M. Pereira   +5 more
openaire   +1 more source

Synthesis of (Na2O,PbO)–Nb2O5, (Na2O,BaO)–Nb2O5, and (K2O,SrO)–Nb2O5 thin films using sol–gel method

Thin Solid Films, 2010
Abstract Homogeneous pore-free Ba 2 NaNb 5 O 15 , KSr 2 Nb 5 O 15 , and 2·Na 2 O–PbO–6·Nb 2 O 5 thin films were fabricated on sapphire substrates using the sol–gel technique. By controlling the gelation and coating process, thickness of thin films fabricated was controllable from ~ 40 nm to ~ 10 μm.
Fei Peng, Dongsheng Li
openaire   +1 more source

Effect of Nb2O5 and MgO/Nb2O5 doping on densification, microstructure and wear resistance of alumina

Ceramics International, 2019
Abstract In this paper, the influence of Nb2O5 single-doping and MgO/Nb2O5 co-doping on the densification, microstructure and wear resistance of Al2O3 has been investigated. The results show that Nb2O5 single-doping can increase the density of alumina effectively, but excessive Nb2O5 will lead to abnormal grain growth.
Cheng Chen, Wei Li
openaire   +1 more source

Structural investigations of nitrided Nb2O5 and Nb2O5–SiO2 sol–gel derived films

Journal of Non-Crystalline Solids, 2008
Sol-gel derived ×Nb 2 O 5 -(100- ×)SiO 2 films (where x = 100, 80, 60, 50, 40, 20, 0 mol%) were nitrided at various temperatures (800°C, 900°C, 1000°C, 1100°C and 1200°C). The structural transformations occurring in the films as a result of ammonolysis were studied using X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron ...
B. Kościelska, A. Winiarski
openaire   +1 more source

The systems Y2O3-Nb2O5 and Ho2O3-Nb2O5: the cubic solid-solution region

Journal of Materials Science Letters, 1984
Determination des parametres cristallins en fonction de la composition dans la region cubique, par diffraction de ...
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The phase diagrams of Na2O and K2O with Nb2O5 and the ternary system Nb2O5-Na2O-Yb2O3

Thermochimica Acta, 1991
Abstract The Nb 2 O,-Na 2 O and Nb 2 -K 2 O systems were re-investigated between 50 and 100 mol% Nb 2 O 5 by thermal analysis, dilatometry and X-ray techniques. Five compounds were found in the investigated region of the first system: NaNbO 3 , Na 2 Nb 4 O 11 , Na 1± x Nb 3± x O 8±2 x ' NaNb 7 O 18 and NaNb 13 O 33 .
E. Irle, R. Blachnik, B. Gather
openaire   +1 more source