635-22-3Relevant academic research and scientific papers
Biomass Sucrose-Derived Cobalt@Nitrogen-Doped Carbon for Catalytic Transfer Hydrogenation of Nitroarenes with Formic Acid
Yuan, Man,Long, Yu,Yang, Jin,Hu, Xiwei,Xu, Dan,Zhu, Yangyang,Dong, Zhengping
, p. 4156 - 4165 (2018/11/01)
Fabrication of non-noble metal-based heterogeneous catalysts by a facile and cost-effective strategy for ecofriendly catalytic transfer hydrogenation (CTH) is of great significance for organic transformations. A cobalt@nitrogen-doped carbon (Co@NC) catalyst was prepared from renewable biomass-derived sucrose, harmless melamine, and earth-abundant Co(AcO)2 as the precursor materials by hydrothermal treatment and carbonization. Co nanoparticles (NPs) were coated with NC shells and uniformly embedded in the NC framework. The as-obtained Co@NC-600 (carbonized at 600 °C) catalyst exhibited excellent catalytic efficiency for CTH of various functionalized nitroarenes with formic acid (FA) as hydrogen donor in aqueous solution. The uniformly incorporated N atoms in the C matrix and the encapsulated Co NPs showed synergistic effects in the CTH reactions. A mechanistic analysis indicated that the protons from FA were activated by Co sites after being captured by N atoms, and then reacted with nitroarenes adsorbed on the surface of the catalysts to generate the corresponding aromatic amines. Moreover, the catalyst showed excellent durability and reusability without obvious decrease in activity even after five reaction cycles. Thus, the study reported herein provides a cost-effective, sustainable strategy for fabrication of biomass-derived non-noble metal-based catalysts for green and efficient catalytic transformations.
Catalytic Materials Based on Surface Coating with Poly(ethyleneimine)-Stabilized Gold Nanoparticles
Ortega-Mu?oz, Mariano,Blanco, Victor,Hernandez-Mateo, Fernando,Lopez-Jaramillo, F. Javier,Santoyo-Gonzalez, Francisco
, p. 3965 - 3973 (2017/09/14)
Gold nanoparticles (AuNPs) can be obtained from HAuCl4 by using poly(ethyleneimine) (PEI) as both reductant and stabilizing agent. However, the known affinity of PEI for different materials has not been exploited to coat them and turn their surface catalytic. We demonstrate that the irradiation of a solution of HAuCl4 and branched PEI 1800 (bPEI2K) with microwave (MW) yields PEI-stabilized AuNPs (MW-PEI@AuNPs) with an average size of 7.6 nm that are catalytically active in the reduction with NaBH4 of different nitroarenes functionalized with a variety of functional groups. Moreover, the as-prepared MW-PE@-AuNPs show affinity for different materials such as polystyrene (standard spectrophotometry disposal cuvettes), polypropylene (Falcon-type tubes), and silica (Silica gel 60), turning their surface catalytic without any additional synthetic step. This feature was exploited to transform standard tubing (Tygon, poly(ether ether ketone), and stainless steel) into flow reactors by simple passage of a solution of MW-PEI@AuNPs. This straightforward functionalization is especially appealing in the case of the stainless-steel tubing, one of the materials more widely used in HPLC, which is of interest for flow nanocatalysis.
Platinum nanoparticles onto pegylated poly(lactic acid) stereocomplex for highly selective hydrogenation of aromatic nitrocompounds to anilines
Oberhauser, Werner,Evangelisti, Claudio,Tiozzo, Cristina,Bartoli, Mattia,Frediani, Marco,Passaglia, Elisa,Rosi, Luca
, p. 50 - 58 (2017/03/16)
A stereocomplexed poly(lactic acid)-polyethyleneglycol copolymer was synthesized and successfully used as recyclable support for Pt nanoparticles, generated by the metal vapor synthesis technique. The confinement of the Pt nanoparticles were determined by thermal analysis. Hydrogenation reactions of chlorinated aromatic nitro compounds, containing other reducible functional groups, to the corresponding anilines occurred with the latter supported Pt nanoparticles in MeOH under very mild reaction conditions (i.e. 30?°C, p(H2)?=?5.0?bar). The covalently attached polyethyleneglycol polymer significantly increased the catalytic activity of the supported Pt nanoparticles compared to an analogous catalytic system which did not contain polyethyleneglycol but the same sized Pt nanoparticles.
Structure and Catalytic Activity of Cr-Doped BaTiO3 Nanocatalysts Synthesized by Conventional Oxalate and Microwave Assisted Hydrothermal Methods
Srilakshmi, Chilukoti,Saraf, Rohit,Prashanth,Rao, G. Mohan,Shivakumara
, p. 4795 - 4805 (2016/06/09)
In the present study synthesis of BaTi1-xCrxO3 nanocatalysts (x = 0.0 ≤ x ≤ 0.05) by conventional oxalate and microwave assisted hydrothermal synthesis methods was carried out to investigate the effect of synthesis methods on the physicochemical and catalytic properties of nanocatalysts. These catalysts were thoroughly characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 physisortion, and total acidity by pyridine adsorption method. Their catalytic performance was evaluated for the reduction of nitrobenzene using hydrazine hydrate as the hydrogen source. Structural parameters refined by Rietveld analysis using XRD powder data indicate that BaTi1-xCrxO3 conventional catalysts were crystallized in the tetragonal BaTiO3 structure with space group P4mm, and microwave catalysts crystallized in pure cubic BaTiO3 structure with space group Pm3μm. TEM analysis of the catalysts reveal spherical morphology of the particles, and these are uniformly dispersed in microwave catalysts whereas agglomeration of the particles was observed in conventional catalysts. Particle size of the microwave catalysts is found to be 20-35 nm compared to conventional catalysts (30-48 nm). XPS studies reveal that Cr is present in the 3+ and 6+ mixed valence state in all the catalysts. Microwave synthesized catalysts showed a 4-10-fold increase in surface area and pore volume compared to conventional catalysts. Acidity of the BaTiO3 catalysts improved with Cr dopant in the catalysts, and this could be due to an increase in the number of Lewis acid sites with an increase in Cr content of all the catalysts. Catalytic reduction of nitrobenzene to aniline studies reveals that BaTiO3 synthesized by microwave is very active and showed 99.3% nitrobenzene conversion with 98.2% aniline yield. The presence of Cr in the catalysts facilitates a faster reduction reaction in all the catalysts, and its effect is particularly notable in conventional synthesized catalysts.
Gold supported on titania for specific monohydrogenation of dinitroaromatics in the liquid phase
Liu, Shuang-Shuang,Liu, Xiang,Yu, Lei,Liu, Yong-Mei,He, He-Yong,Cao, Yong
, p. 4162 - 4169 (2014/09/29)
Liquid-phase selective monohydrogenation of various substituted dinitroaromatics to the corresponding valuable nitroanilines was investigated on gold-based catalysts. Special attention was paid to the effect of Au particle size on this monoreduction reaction. Interestingly, TiO2 supported gold catalysts containing a relatively larger mean Au particle size (>5 nm) showed far superior chemoselectivity for specific mono-hydrogenation of dinitroaromatics, with the highest performance attainable for the catalyst bearing Au particles of ca. 7.5 nm. Results in the intermolecular competitive hydrogenation showed that the intrinsic higher accumulation rates of the desired nitroanilines associated with the catalyst possessing larger Au particles were responsible for the high chemoselectivity observed. the Partner Organisations 2014.
Perovskite-type ferromagnetic BiFeO3 nanopowder: A new magnetically recoverable heterogeneous nanocatalyst for efficient and selective transfer hydrogenation of aromatic nitro compounds into aromatic amines under microwave heating
Farhadi,Rashidi
, p. 1021 - 1031 (2013/02/23)
Perovskite-type ferromagnetic BiFeO3 nanopowder was readily synthesized via thermal decomposition of Bi[Fe(CN)6].5H2O complex and characterized using thermal analysis (TGA/DSC), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), magnetic measurement and Brunauer-Emmett- Teller (BET) specific surface area measurements. The magnetic measurements show a ferromagnetic behavior for the BiFeO3 nanoparticles at room temperature. This nanosized ferromagnetic oxide with an average particle size of approximately 20 nm and a specific surface area of 48.5 m2/g was used as a new magnetically recoverable heterogeneous nanocatalyst for the highly efficient and selective reduction of aromatic nitro compounds into their corresponding amines by using propan-2-ol as the hydrogen donor under microwave irradiation. This method is regio- and chemoselective, clean, inexpensive and compatible with the substrates having hydrogenlyzable or reducible functional groups. As compared with conventional heating, this method is very fast and suitable for the large-scale preparation of different substituted anilines as well as other arylamines. The catalyst can also be reused without loss of activity. Iranian Chemical Society 2012.
Perovskite-type LaFeO3 nanoparticles prepared by thermal decomposition of the La[Fe(CN)6]·5H2O complex: A new reusable catalyst for rapid and efficient reduction of aromatic nitro compounds to arylamines with propan-2-ol under microwave irradiation
Farhadi, Saeid,Siadatnasab, Firouzeh
experimental part, p. 108 - 116 (2011/05/19)
Perovskite-type LaFeO3 nanoparticles were readily synthesized via thermal decomposition of the La[Fe(CN)6]·5H2O complex and characterized by using thermal analysis (TGA), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and BET specific surface area measurement. This nanosized perovskite-type oxide with an average particle size of 35 nm and a specific surface area 38.5 m2/g was used as a new reusable heterogeneous catalyst for highly efficient and selective reduction of aromatic nitro compounds into their corresponding amines by using propan-2-ol as the hydrogen donor under microwave irradiation. This method is regio- and chemoselective, clean, inexpensive and compatible with the substrates having hydrogenlysable or reducible functional groups. As compared with conventional heating, this method is very fast and suitable for large scale preparation of different substituted anilines as well as other arylamines. The catalyst can also be reused without observable loss of its activity.
Microwave-assisted rapid and efficient reduction of aromatic nitro compounds to amines with propan-2-ol over Nanosized perovskite-type SmFeO 3 powder as a new recyclable heterogeneous catalyst
Farhadi, Saeid,Siadatnasab, Firouzeh,Kazem, Maryam
experimental part, p. 104 - 108 (2011/06/27)
Nanosized perovskite-type SmFeO3 powder, prepared through the thermal decomposition of Sm[Fe(CN)6].4H2O with an average particle diameter of 28 nm and a specific surface area of 42 m2 g-1, was used as a recyclable heterogeneous catalyst for the efficient and selective reduction of aromatic nitro compounds into the corresponding amines by using propan-2-ol as a hydrogen donor (reducing agent) and KOH as a promoter under microwave irradiation. This highly regio-and chemoselective catalytic method is fast, clean, inexpensive, high yielding and also compatible with the substrates containing easily reducible functional groups. In addition, the nanosized SmFeO3 catalyst can be reused without loss of activity.
Highly chemo-and regioselective transfer reduction of aromatic nitro compounds using ammonium formate catalyzed by supported gold nanoparticles
Lou, Xia-Bing,He, Lin,Qian, Yue,Liu, Yong-Mei,Cao, Yong,Fan, Kang-Nian
supporting information; experimental part, p. 281 - 286 (2011/04/16)
A highly chemo-and regioselective reduction of a wide diversity of aromatic nitro compounds to the corresponding amines has been achieved by a combination of gold nanoparticles supported on titania and ammonium formate (HCOONH 4) in ethanol at room temperature. Furthermore, a direct and mild route to formanilides from aromatic nitro compounds bearing different functional groups by reductive N-formylation using the gold-mediated transfer reduction protocol is also established.
NiO nanoparticles prepared via thermal decomposition of the bis(dimethylglyoximato)nickel(II) complex: A novel reusable heterogeneous catalyst for fast and efficient microwave-assisted reduction of nitroarenes with ethanol
Farhadi, Saeid,Kazem, Maryam,Siadatnasab, Firouzeh
scheme or table, p. 606 - 613 (2011/04/16)
NiO nanoparticles with an average size of 12 nm and a high specific surface area of 88.5 m2/g were easily prepared via the thermal decomposition of the complex Ni(dmgH)2 and were characterized by TGA, XRD, FT-IR, TEM and BET surface area measurement. This nanosized transition metal oxide was used as a new heterogeneous catalyst for the reduction of nitroarenes under microwave irradiation. The efficient and selective reduction of aromatic nitro compounds into their corresponding amines was observed by using ethanol as a hydrogen donor (reducing agent) and KOH as a promoter under microwave irradiation. This highly regio-and chemoselective method is fast, simple, inexpensive, high yielding, clean and compatible with several sensitive functionalities, such as halogens,-OH,-OCH3,-CHO,-COCH 3,-COOH,-COOEt,-CONH2,-CN,-CHCH2 and-NHCOCH3. This method is suitable for the large scale preparation of different substituted anilines as well as other arylamines. In addition, the catalytic activity of nanosized NiO is higher than that of the bulk sample.
