16750-67-7Relevant articles and documents
Ultrafine silver nanoparticles supported on a covalent carbazole framework as high-efficiency nanocatalysts for nitrophenol reduction
Gong, Wei,Wu, Qianqian,Jiang, Guoxing,Li, Guangji
, p. 13449 - 13454 (2019)
A novel conjugated microporous polymer (CMP) material CZ-TEB was synthesized with a carbazole analogue and 1,3,5-triethynylbenzene. It possessed a high specific surface area, excellent thermal stability and layered-sheet morphology. Furthermore, ultrafine silver nanoparticles were successfully immobilized on CZ-TEB, thus preparing a nanocatalyst Ag0@CZ-TEB. To evaluate its catalytic performance, Ag0@CZ-TEB was exploited in the reduction reaction of nitrophenols, a family of priority pollutants. Ag0@CZ-TEB exhibited high catalytic ability, convenient recovery and excellent reusability. Strikingly, the normalized rate constant (knor) of the reduction reaction of 4-NP to 4-AP is as high as 21.49 mmol-1 s-1. This result shows a significant improvement over all previously reported work. We purposed to use a "capture-release" model to explain the high catalytic ability of Ag0@CZ-TEB. This explanation is supported by further experimental results that agree well with the "capture-release" model.
Zwitterionic Surfactant stabilized palladium nanoparticles as catalysts in aromatic nitro compound reductions
Souza, Franciane D.,Fiedler, Haidi,Nome, Faruk
, p. 372 - 381 (2016/03/19)
Palladium nanoparticles (NPs) stabilized by ImS3-14, a zwitterionic surfactant structurally related to ionic liquids, are revealed here to be good catalysts for the reduction of a large number of substituted aromatic nitro compounds. Our mass spectrometry results are consistent with the formation of amino products in a direct route, where the aromatic nitro compounds are initially reduced to nitroso compounds, which are then reduced to the hydroxylamine derivatives and finally to the anilines. Activation parameters showed that for most Pd catalysts reported in the literature, the mechanism seems to be similar, with lower enthalpy of activation (ΔH?) being compensated by more negative entropy of activation (ΔS?). As a result, the reaction is thermally compensated and the rate constants for most reactions rather similar. Furthermore, Pd NPs stabilized by ImS3-14 showed efficient catalytic activities for the reduction of aromatic nitro compounds, with high conversion and good selectivity even using very low loadings of metal.
Selective oxidation of sulfides and oxidative bromination of organic substrates catalyzed by polymer anchored Cu(II) complex
Islam,Roy, Anupam Singha,Mondal, Paramita,Tuhina, Kazi,Mobarak, Manir,Mondal, John
supporting information; experimental part, p. 127 - 131 (2012/01/17)
A new polymer-anchored Cu(II) complex has been synthesized and characterized. The catalytic performance of the complex has been tested for the oxidation of sulfides and in oxidative bromination reaction with hydrogen peroxide as the oxidant. Sulfides have been selectively oxidized to the corresponding sulfoxides in excellent yields and in the presence of KBr as the bromine source, organic substrates have been selectively converted to mono bromo substituted compounds using polymer-anchored Cu(II) catalyst. This catalyst showed excellent catalytic activity, high selectivity, and recyclability. The polymer-anchored Cu(II) catalyst could be easily recovered by filtration and reused more than five times without appreciable loss of its initial activity.
