3964-52-1Relevant articles and documents
Catalytic Activities of Mono- and Bimetallic (Gold/Silver) Nanoshell-Coated Gold Nanocubes toward Catalytic Reduction of Nitroaromatics
Sundarapandi, Manickam,Viswanathan, Perumal,Sivakumar, Shanmugam,Ramaraj, Ramasamy
, p. 13897 - 13904 (2018)
A new class of core-shell metallic nanostructures with tunable near-surface composition and surface morphology with excellent catalytic activity is reported. Very thin shells of metal nanoassemblies such as monolayer (Ag and Au), bilayer of Ag or Au, and AgAu alloy layer with controlled size and morphology were deposited onto a gold nanocube (AuNC) core. UV-vis absorption spectroscopy and high-resolution transmission electron microscopy analyses along with selected-area electron diffraction, energy dispersive X-ray spectroscopy, inductively coupled plasma mass spectrometer, and X-ray diffraction techniques were used to characterize the prepared core-shell nanocubes. High-angle annular dark field scanning transmission electron microscopy-energy dispersive X-ray spectroscopy mapping images were recorded for the bilayer shell and alloy layer shell in the core-shell nanostructures. Reduction of 4-nitroaniline in the presence of sodium borohydride was chosen to validate the catalytic activity of the prepared core-shell metal nanocubes. Interestingly, the AgAu alloy shell layer over the AuNC (AuNC1@Ag0.25Au0.25) showed excellent catalytic activity compared with the pristine AuNC and monolayer and bilayer core-shell nanostructures.
Nitrogen-doped carbon supported iron oxide as efficient catalysts for chemoselective hydrogenation of nitroarenes
Xu, Shaodan,Yu, Deqing,Liao, Shangfu,Ye, Tao,Sheng, Huadong
, p. 96431 - 96435 (2016)
Chemoselective hydrogenation has been widely used in the production of fine chemicals, and developing heterogeneous catalysts with high activity and chemoselectivity is always a challenging topic. Herein, we report a new type of catalysts synthesized from biomass-derived chitosan and non-noble iron, which is denoted as nitrogen-doped carbon supported iron (Fe/N-C). TEM and XRD characterization indicate the presence of iron species. Interestingly, the Fe/N-C catalysts exhibited excellent catalytic performances in the hydrogenation of nitroarenes, and excellent yields of target aniline products could be obtained under industrially viable conditions.
Record-high catalytic hydrogenated activity in nitroarenes reduction derived from in-situ nascent active metals enabled by constructing bimetallic phosphate
Yang, Fu,Wang, Jin,Gao, Shuying,Zhou, Shijian,Kong, Yan
, (2020/03/10)
Herein, we report an excellent in-situ exsolution triggered hydrogenated catalyst F-Ni/Cu-P-RT started from bimetallic phosphate Ni/Cu-P-RT, affording an ultrafast catalytic hydrogenated rate (20 s even 5 s) in nitrophenol reduction. In the first catalytic cycle, we proved the enhanced catalytic reduction activity of bimetallic Ni/Cu-P-RT within 50 s compared to monometallic counterparts. The kinetics results revealed Ni/Cu-P-RT affords the reaction rate K of 2.85/4.23/6.6 min?1 at 20, 30, and 40 °C with the activation energy 32 kJ/mol. Impressively, the involved reaction induction period is visibly observed and interpreted by reconstruction and evolution of active metal during the reaction, but was eliminated through integrating two metal Cu-Ni by regulation of electronic band energy of phosphate from 4.1–3.5 eV. The nascent Cu and Ni nanoparticles as reaction-preferred active species were in-situ exsolved partially after adding NaBH4, triggering the resulted higher active and stable F-Ni/Cu-P-RT(20 s, 14.1 min?1) in later multiple cycles.
Fe-Catalyzed Amination of (Hetero)Arenes with a Redox-Active Aminating Reagent under Mild Conditions
Liu, Jianzhong,Wu, Kai,Shen, Tao,Liang, Yujie,Zou, Miancheng,Zhu, Yuchao,Li, Xinwei,Li, Xinyao,Jiao, Ning
supporting information, p. 563 - 567 (2017/01/18)
A novel and efficient Fe-catalyzed direct C?H amination (NH2) of arenes is reported using a new redox-active aminating reagent. The reaction is simple, and can be performed under air, mild, and redox-neutral conditions. This protocol has a broad substrate scope and could be used in the late-stage modification of bioactive compounds. Mechanistic studies demonstrate that a radical pathway could be involved in this transformation.