scholarly journals Annihilation of the Catalytic Activity in Butene Isomerization of Porous Vycor Glass by Washing with EDTA Aqueous Solution

1977 ◽  
Vol 50 (12) ◽  
pp. 3411-3412 ◽  
Author(s):  
Shoji Hirai ◽  
Akira Morikawa ◽  
Yoshio Ishinaga ◽  
Kiyoshi Otsuka ◽  
Yuji Wada
Keyword(s):  
Aqueous Solution ◽  
Catalytic Activity ◽  
Vycor Glass ◽  
Porous Vycor Glass ◽  
Butene Isomerization

Nickel(II) and manganese(III) tetraazaannulenes complexes encapsulated in porous Vycor glass (PVG): investigation of catalytic activity

2004 ◽  
Vol 222 (1-2) ◽  
pp. 213-222 ◽  
Author(s):  
José Maurício Almeida Caiut ◽  
Shirley Nakagaki ◽  
Geraldo Roberto Friedermann ◽  
Sueli Maria Drechsel ◽  
Aldo José Gorgatti Zarbin
Keyword(s):  
Catalytic Activity ◽  
Vycor Glass ◽  
Porous Vycor Glass

Immobilization of iron porphyrins into porous vycor glass: characterization and study of catalytic activity

2002 ◽  
Vol 185 (1-2) ◽  
pp. 203-210 ◽  
Author(s):  
Shirley Nakagaki ◽  
André Ricardo Ramos ◽  
Flávio Luiz Benedito ◽  
Patricio Guillermo Peralta-Zamora ◽  
Aldo José Gorgatti Zarbin
Keyword(s):  
Catalytic Activity ◽  
Iron Porphyrins ◽  
Vycor Glass ◽  
Porous Vycor Glass

Decomposition of hydrogen peroxide on a two-component NiO-CdO catalyst and the effect of ionizing radiation on its catalytic properties

1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Nickel Oxide ◽  
Catalytic Properties ◽  
Cadmium Oxide ◽  
Chemisorb Oxygen ◽  
Composition Region ◽  
Chemisorbed Oxygen ◽  
Two Component

The catalytic properties of two-component catalyst nickel oxide-cadmium oxide with the proportions of the components covering the whole composition region 0-100% were examined by studying the decomposition of hydrogen peroxide in aqueous solution on it. In the range 0-25 mol.% CdO, cadmium oxide is found to affect infavourably the ability of nickel oxide to chemisorb oxygen. The amount of the chemisorbed oxygen increases several times on gamma irradiation of the samples. The effect of cadmium oxide on the catalytic activity of the system shows up in fresh samples only indirectly via the changed amount of the oxygen chemisorbed. In older samples the initial catalytic activity of the system is changed, which can be explained based on the concept of bivalent catalytic centres in terms of the co-action of the catalytic centres of the two oxides, which are in equilibrium. The irradiation of the system under study speeds up the processes leading to the establishing of this equilibrium which is thermally very stable, and results in a substantial increase of the catalytic activity of the samples investigated.

scholarly journals Thermal properties of metal-metal bonded Pd(I) complexes supported onto porous Vycor glass

2008 ◽  
Vol 80 (2) ◽  
pp. 263-269
Author(s):  
Iara F. Gimenez ◽  
Oswaldo L. Alves
Keyword(s):  
Solid State ◽  
Thermal Stabilization ◽  
Decomposition Products ◽  
Vycor Glass ◽  
X Ray ◽  
Porous Vycor Glass ◽  
Metal Metal ◽  
Condensed Phosphates ◽  
Diffuse Reflectance Infrared ◽  
Immobilized Complexes

Thermal behavior of the complexes Pd2(dppm)2Cl2, Pd2(dppm)2(SnCl3)Cl and Pd2(dppm)2(SnCl3)2 (dppm = bis[diphenylphosphino(methane)], ((C6H5)2PCH2P(C6H5)2) in the solid state and immobilized onto porous Vycor glass was studied. Similar decomposition mechanisms were observed for the solid and immobilized complexes, with a small thermal stabilization upon immobilization. The decomposition products were characterized by X-ray diffractometry, Raman and diffuse reflectance infrared spectroscopy, which indicated the presence of a mixture of metallic palladium and oxidized species such as PdO,condensed phosphates, SnO2 and SnP2O7. According to X-ray diffractometry, the decomposition products of the immobilized complexes presented higher amounts of PdO than the solid-state residues, probably as an effect of interactions with silanol groups present in the glass surface.

Stimuli-responsive Janus mesoporous nanosheets towards robust interfacial emulsification and catalysis

2020 ◽  
Vol 7 (12) ◽  
pp. 3242-3249
Author(s):  
Jiangyan Yang ◽  
Jialin Wang ◽  
Yijiang Liu ◽  
Huaming Li ◽  
Zhiqun Lin
Keyword(s):  
Aqueous Solution ◽  
Catalytic Activity ◽  
Stimuli Responsive ◽  
Phase Type

Stimuli-responsive amphiphilic Janus mesoporous nanosheets with pH-triggered emulsification performance, switchable catalytic activity in aqueous solution and oil-phase-type-dependent catalytic activity at an emulsion interface were crafted.

scholarly journals AuNPs-Based Thermoresponsive Nanoreactor as an Efficient Catalyst for the Reduction of 4-Nitrophenol

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 963
Author(s):  
Wei Liu ◽  
Xiaolian Zhu ◽  
Chengcheng Xu ◽  
Zhao Dai ◽  
Zhaohui Meng
Keyword(s):  
Aqueous Solution ◽  
Electron Transfer ◽  
Phase Transformation ◽  
Catalytic Activity ◽  
Catalytic Efficiency ◽  
Environmental Pollutant ◽  
Temperature Sensitive ◽  
Efficient Catalyst ◽  
Catalytic Rate ◽  
Silica Core

A new AuNPs-based thermosensitive nanoreactor (SiO2@PMBA@Au@PNIPAM) was designed and prepared by stabilizing AuNPs in the layer of poly(N,N’-methylenebisacrylamide) (PMBA) and subsequent wrapping with the temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) layer. The new nanoreactor exhibited high dispersibility and stability in aqueous solution and effectively prevented the aggregation of AuNPs caused by the phase transformation of PNIPAM. The XPS and ATR-FTIR results indicated that AuNPs could be well stabilized by PMBA due to the electron transfer between the N atoms of amide groups in the PMBA and Au atoms of AuNPs. The catalytic activity and thermoresponsive property of the new nanoreactor were invested by the reduction of the environmental pollutant, 4-nitrophenol (4-NP), with NaBH4 as a reductant. It exhibited a higher catalytic activity at 20 °C and 30 °C (below LCST of PNIPAM), but an inhibited catalytic activity at 40 °C (above LCST of PNIPAM). The PNIPAM layer played a switching role in controlling the catalytic rate by altering the reaction temperature. In addition, this nanoreactor showed an easily recyclable property due to the existence of a silica core and also preserved a rather high catalytic efficiency after 16 times of recycling.

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