95-76-1Relevant articles and documents
Lanthanum ion doped nano TiO2 encapsulated in zeozyme and impregnated in a polystyrene film as a photocatalyst for the degradation of diuron in an aquatic ecosystem
Saranya,Sathiyanarayanan,Maheswari
, p. 110970 - 110975 (2016)
The occurrence of chlorinated herbicide diuron in water bodies is considered serious pollution and a major health hazard to flora, fauna and mankind. In the present investigation, we studied the photocatalytic degradation of diuron in an aquatic ecosystem using lanthanum ion doped nano TiO2 (Lnp) encapsulated in NaY zeolite pores (1 : 10) and impregnated in polystyrene film (ZLT). The hydrophobic nature of the polystyrene support resulted in an efficient and highly recoverable heterogeneous system. Catalyst characterization was carried out by FT-IR, XRD, DRS-UV, fluorescence, BET, SEM-EDAX and XPS. BET results revealed the successful loading of lanthanum ion doped TiO2 (Lnp) inside the NaY zeolite pores via a decrease in surface area for the zeolite encapsulated Lnp (ZLnp) as compared to NaY zeolite alone. DRS UV supported the impregnation of ZLnp in the polystyrene films; the bathochromic shift (Δλ) was 4 nm and the hypochromic shift decreased in intensity 10 fold. The photocatalytic reaction was carried out at a concentration of 20 mg L-1 of diuron, with 0.01 M H2O2 and a catalytic amount of 500 mg L-1 ZLT under unstirred conditions. Degradation of diuron by ZLT reached 40% after 2 hours. Noteworthy features are the good results under optimized conditions and that the same film models were used successfully in the presence of zebra fish (Danio rerio). The present investigation also demonstrated successful re-use of the photocatalytic film six times without any appreciable loss in catalytic activity. From the abovementioned results, it was proven that ZLT is an efficient and ecofriendly catalyst.
Kinetics of the chemical degradation of diuron.
Salvestrini, Stefano,Di Cerbo, Paola,Capasso, Sante
, p. 69 - 73 (2002)
The influence of pH and buffer concentration on the chemical degradation of diuron in water has been analysed over a wide temperature range. The process irreversibly gives 3,4-dichloroaniline as the only product containing the phenyl ring. H+, OH- and phosphate buffer are efficient catalysts of the reaction. The rate constant first increases rapidly at low buffer concentrations and then gradually levels off at higher ones. At 40 degrees C and high phosphate concentration (>0.01 M), or in the extreme pH regions, the half-life is approximately 4 months and the activation energy is 127 +/- 2 kJmol(-1).
Catalytic Hydrogenation of Urea Derivatives and Polyureas
Kumar, Amit,Luk, James
supporting information, p. 4546 - 4550 (2021/08/30)
We present herein the catalytic hydrogenation of various urea derivatives to amines and methanol. The reaction is catalyzed by a ruthenium or an iridium Macho pincer complex and produces amine and methanol in very good to excellent yields. Moreover, we also expand this concept to demonstrate the first example of the hydrogenative depolymerization of polyureas to produce diamines and methanol in moderate yields.
Highly efficient hydrogenation reduction of aromatic nitro compounds using MOF derivative Co-N/C catalyst
Dai, Yuyu,Li, Xiaoqing,Wang, Likai,Xu, Xiangsheng
, p. 22908 - 22914 (2021/12/24)
The direct hydrogenation reduction of aromatic nitro compounds to aromatic amines with non-noble metals is an attractive area. Herein, the pyrolysis of Co(2-methylimidazole)2 metal-organic framework successfully produces a magnetic Co-N/C nanocomposite, which exhibits a porous structure with a high specific area and uniform Co nanoparticle distribution in nitrogen-doped graphite. In addition, the Co-N/C catalysts possess high cobalt content (23%) with highly active β-Co as the main existing form and high nitrogen content (3%). These interesting characteristics endow the Co-N/C nanocomposite with excellent catalytic activity for the hydrogenation reduction of nitro compounds under mild conditions. In addition, the obtained Co-N/C nanocomposites possess a broad substrate scope and good cycle stability for the reduction of halogen-substituted or carbonyl substituted phenyl nitrates. This journal is
Synthesis of CoFe2O4@Pd/Activated carbon nanocomposite as a recoverable catalyst for the reduction of nitroarenes in water
Hamadi, Hosein,Kazeminezhad, Iraj,Mohammadian, Sara
, (2021/07/06)
Efficient reduction of nitro compounds into amines is an important industrial transformation. So, it is a great deal to design new catalysts for efficient reduction of the nitro compounds especially in water. In this work, a new magnetic Pd/activated carbon nanocomposite (CoFe2O4@Pd/AC) was synthesized via metal-impregnation-pyrolysis method. The CoFe2O4@Pd/AC was fully characterized by FT-IR, PXRD, FESEM, TEM, VSM, EDX-mapping and BET techniques. The results showed that CoFe2O4@Pd/AC is a highly reactive and easily recoverable magnetic catalyst for the reduction of the nitro compounds by using NaBH4 in water. For instance, aniline was obtained in high yield (99%) after 75 ?min at 25 ?C by using just 6 ?mg of the catalyst. In addition, CoFe2O4@Pd/AC was recovered by a simple magnetic decantation and it exhibits stable activity and remains intact during the catalytic process with no significant loss in activity (8 cycles).
Indirect reduction of CO2and recycling of polymers by manganese-catalyzed transfer hydrogenation of amides, carbamates, urea derivatives, and polyurethanes
Liu, Xin,Werner, Thomas
, p. 10590 - 10597 (2021/08/20)
The reduction of polar bonds, in particular carbonyl groups, is of fundamental importance in organic chemistry and biology. Herein, we report a manganese pincer complex as a versatile catalyst for the transfer hydrogenation of amides, carbamates, urea derivatives, and even polyurethanes leading to the corresponding alcohols, amines, and methanol as products. Since these compound classes can be prepared using CO2as a C1 building block the reported reaction represents an approach to the indirect reduction of CO2. Notably, these are the first examples on the reduction of carbamates and urea derivatives as well as on the C-N bond cleavage in amides by transfer hydrogenation. The general applicability of this methodology is highlighted by the successful reduction of 12 urea derivatives, 26 carbamates and 11 amides. The corresponding amines, alcohols and methanol were obtained in good to excellent yields up to 97%. Furthermore, polyurethanes were successfully converted which represents a viable strategy towards a circular economy. Based on control experiments and the observed intermediates a feasible mechanism is proposed.
Minimization of Back-Electron Transfer Enables the Elusive sp3 C?H Functionalization of Secondary Anilines
Zhao, Huaibo,Leonori, Daniele
supporting information, p. 7669 - 7674 (2021/03/08)
Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N-Dialkyl-derivatives enable radical generation α to the N-atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back-electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α-anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C?H functionalization.
Synthesis and characterization of go-chit-ni nanocomposite as a recoverable nanocatalyst for reducing nitroarenes in water
Azadi, Roya,Sarvestani, Mosayeb
, p. 523 - 531 (2020/07/17)
In the present study, nickel nanoparticles (Ni-NPs) immobilized on graphene oxide-chitosan (GO-Chit-Ni) have been synthesized and characterized as a catalyst for reduction of nitroarenes in water. For this purpose, GO has been functionalized with chitosan (GO-Chit). Then, Ni-NPs were immobilized on the surface of GO-Chit using a simple method. The GO-Chi-Ni nanocomposites were characterized using Fourier Transforms Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), X-Ray Diffraction Measurements (XRD), and Atomic Adsorption Spectrometry (AAS). The GO-Chi-Ni nanoparticles demonstrated appropriate catalytic activity in reducing nitroarenes to aryl amines in the existence of sodium borohydride (NaBH4) aqueous solution as a hydrogen source at 80oC. This catalytic system applies environmentally benign water as a solvent that is cheap, easily accessible, non-toxic, non-volatile, non-flammable and thermally stable. This type of catalyst can be applied several times with no considerable change in its performance.
Synthesis method of halogenated aniline
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Paragraph 0153-0155, (2020/08/09)
The invention provides a synthesis method of halogenated aniline. The synthesis method comprises the following steps: taking a carbon-coated nickel nano composite material containing alkaline-earth metals as a catalyst, and catalyzing a hydrogenation reduction reaction of halogenated nitrobenzene in a hydrogen atmosphere, wherein the nano composite material contains a core-shell structure with a shell layer and an inner core, the shell layer is a graphitized carbon layer containing alkaline-earth metals and oxygen, and the inner core is nickel nano particles. According to the method, the nanocomposite material is used as a catalyst; a carbon material and the nickel nano particles generate a synergistic effect and a good catalytic effect, the alkaline-earth metals of the shell layer further synergistically improve the catalytic performance of the nano composite material, and the catalyst is used for hydrogenation reduction of halogenated nitrobenzene to synthesize halogenated aniline,has excellent activity, selectivity and safety, and can effectively solve the dehalogenation problem in the reaction process.
Synthesis method of halogenated aniline
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Paragraph 0138-0140, (2020/08/09)
The invention provides a synthesis method of halogenated aniline. The synthesis method comprises the following steps: taking a carbon-coated nickel nano composite material containing alkali metals asa catalyst, and catalyzing a hydrogenation reduction reaction of halogenated nitrobenzene in a hydrogen atmosphere; wherein the nano composite material contains a core-shell structure with a shell layer and an inner core, the shell layer is a graphitized carbon layer containing alkali metals, nitrogen and oxygen, and the inner core is nickel nano particles. According to the method, the nano composite material is used as a catalyst; a carbon material and the nickel nano particles generate a synergistic effect and a good catalytic effect, the alkali metals of the shell layer further synergistically improve the catalytic performance of the nano composite material, and the catalyst is used for hydrogenation reduction of halogenated nitrobenzene to synthesize halogenated aniline, has excellentactivity, selectivity and safety, and can effectively solve the dehalogenation problem in the reaction process.
