7369-50-8Relevant academic research and scientific papers
Copper(II)-Doped ZIF-8 as a Reusable and Size Selective Heterogeneous Catalyst for the Hydrogenation of Alkenes using Hydrazine Hydrate
Nagarjun, Nagarathinam,Arthy, Kannan,Dhakshinamoorthy, Amarajothi
, p. 2108 - 2119 (2021/06/01)
In recent years, synthesis of mixed-metal organic frameworks has received considerable attention due to their superior performance than with mono-metallic metal organic frameworks (MOFs). In the present manuscript, Cu2+ ions are doped within the framework of ZIF-8 (ZIF: Zeolitic Imidazolate Frameworks) to obtain Cu@ZIF-8 and is characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV-Visible diffuse reflectance spectra (DRS), scanning electron microscope (SEM) and transmission electron microcope (TEM) studies. The reaction conditions are optimized with styrene as a model substrate using Cu@ZIF-8 as a solid catalyst. Heterogeneity of the reaction is confirmed by leaching test and the solid is reusable for three recycles with no diminishing activity. Further, the structural integrity of Cu@ZIF-8 is also retained after hydrogenation of styrene as evidenced by powder X-ray diffraction. The size selective catalysis of Cu@ZIF-8 is demonstrated by comparing the activity of Cu2+ ions adsorbed over ZIF-8 solid (Cu/ZIF-8) in the hydrogenation of 1-hexene, 1-octene, cyclohexene, cyclooctene and t-stilbene. The catalytic results indicate that Cu/ZIF-8 shows superior activity than Cu@ZIF-8 for all these olefins due to the lack of diffusion to access the active sites (Cu2+). In contrast, Cu@ZIF-8 exhibits higher activity for those olefins with lower molecular dimensions (1-hexene, 1-octene) than the pores of ZIF-8 indicating the facile diffusion of these substrates inside the pores ZIF-8 while poor activity is observed with t-stilbene due to its larger molecular dimension than the pore apertures of ZIF-8. These catalytic data clearly establish the size selective hydrogenation of Cu@ZIF-8 due to the effective confinement provided by ZIF-8 framework and the presence of the active sites within the framework. Furthermore, this is the first report showing the size selective hydrogenation of olefins promoted by Cu@ZIF-8 (mixed-metal MOFs) compared to other noble metal nanoparticles (NPs) embedded over MOFs as catalysts.
Water-soluble NHC-stabilized platinum nanoparticles as recoverable catalysts for hydrogenation in water
Baquero, Edwin A.,Chaudret, Bruno,De Jesús, Ernesto,Flores, Juan C.,Gonzalez-Arellano, Camino,Ruiz-Varilla, Andrea M.
, p. 2874 - 2881 (2020/06/17)
The production of water-soluble and stable metallic nanoparticles that can act as recoverable catalysts still remains a challenge. Herein we report the behavior of a series of water-soluble platinum nanoparticles containing different sulfonated NHC ligands as recoverable catalysts for the hydrogenation of aromatic compounds in pure water. The NHC-protected nanoparticles are found to be active and, in general, can be reutilized with no loss of activity or selectivity, although differences are observed depending on the substitution of the NHC ligand or on the substrate being hydrogenated. Pt leaching was determined to be only 0.03-0.29%. TEM images reveal that the shape of the nanoparticles remains unaltered after catalysis. However, the size of the particles increased, although with no influence on their catalytic properties in many instances.
Finely Controlled Platinum Nanoparticles over ZnO Nanorods for Selective Hydrogenation of 3-Nitrostyrene to 3-Vinylaniline
Gao, Tongtong,Liu, Zhong-Wen,Shi, Wen,Zhang, Bingsen,Zhang, Liyun,Zhang, Ying
, (2020/07/13)
Metallic platinum nanocatalysts play a key role in the liquid-phase selective hydrogenation of substrates with more than one unsaturated bond. However, the commonly applied explanation for the effects of different electronic and geometric properties of catalysts on reactions remains of a heuristic nature due to the difficulties involved in preparing catalysts with precise structure. In this work, we have directly loaded pre-synthesized metallic platinum nanoparticles onto well-structured ZnO nanorods and then subjected them to thermal treatment in a reductive atmosphere for different temperatures. The effects of the different electronic and geometric properties of the catalysts on the selective reduction of 3-nitrostyrene to 3-vinylaniline as a model reaction have been rigorously explored through an analysis of the catalyst structures and the activity and selectivity profiles. Both the electron transfer from zinc to platinum and the decreased platinum surface density as a result of the formation of PtZn intermetallic compounds are key factors for improving the selectivity for the desired 3-vinylaniline. Azobenzene was detected in the reaction with all the Pt/ZnO catalysts after 10–90 min, which indicates that the reaction follows a condensation mechanism.
Chemoselective Hydrogenation of Nitroaromatics at the Nanoscale Iron(III)–OH–Platinum Interface
Fu, Gang,Li, Laiyang,Ming, Jiang,Qin, Ruixuan,Ren, Juan,Wang, Yongke,Wang, Yu,Zhang, Wuyong,Zheng, Nanfeng,Zhou, Wenting
, p. 12736 - 12740 (2020/06/01)
Catalytic hydrogenation of nitroaromatics is an environment-benign strategy to produce industrially important aniline intermediates. Herein, we report that Fe(OH)x deposition on Pt nanocrystals to give Fe(OH)x/Pt, enables the selective hydrogenation of nitro groups into amino groups without hydrogenating other functional groups on the aromatic ring. The unique catalytic behavior is identified to be associated with the FeIII-OH-Pt interfaces. While H2 activation occurs on exposed Pt atoms to ensure the high activity, the high selectivity towards the production of substituted aniline originates from the FeIII-OH-Pt interfaces. In situ IR, X-ray photoelectron spectroscopy (XPS), and isotope effect studies reveal that the Fe3+/Fe2+ redox couple facilitates the hydrodeoxygenation of the -NO2 group during hydrogenation catalysis. Benefitting from FeIII-OH-Pt interfaces, the Fe(OH)x/Pt catalysts exhibit high catalytic performance towards a broad range of substituted nitroarenes.
Environmentally responsible, safe, and chemoselective catalytic hydrogenation of olefins: ppm level Pd catalysis in recyclable water at room temperature
Gallou, Fabrice,Gao, Eugene S.,Lipshutz, Bruce H.,Takale, Balaram S.,Thakore, Ruchita R.
supporting information, p. 6055 - 6061 (2020/10/14)
Textbook catalytic hydrogenations are typically presented as reactions done in organic solvents and oftentimes under varying pressures of hydrogen using specialized equipment. Catalysts new and old are all used under similar conditions that no longer reflect the times. By definition, such reactions are both environmentally irresponsible and dangerous, especially at industrial scales. We now report on a general method for chemoselective and safe hydrogenation of olefins in water using ppm loadings of palladium from commercially available, inexpensive, and recyclable Pd/C, together with hydrogen gas utilized at 1 atmosphere. A variety of alkenes is amenable to reduction, including terminal, highly substituted internal, and variously conjugated arrays. In most cases, only 500 ppm of heterogeneous Pd/C is sufficient, enabled by micellar catalysis used in recyclable water at room temperature. Comparison with several newly introduced catalysts featuring base metals illustrates the superiority of chemistry in water.
Method for preparing 1-ethyl-3-nitrobenzene
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Page/Page column 4-6, (2019/12/08)
The invention discloses a method for preparing 1-ethyl-3-nitrobenzene. The method comprises the following steps: S1. sequentially adding methanol and m-nitroacetophenone into a reaction bottle, cooling the temperature of the reaction bottle to 0 DEG C, adding sodium borohydride in batches, carrying out a reaction at a normal temperature under normal pressure, concentrating methanol, carrying out extracting, merging organic phases, and carrying out concentrating, so as to obtain 1-(3-nitrobenzophenone)ethanol; S2. sequentially adding dichloromethane, the 1-(3-nitrobenzophenone)ethanol, imidazole, triphenyl phosphine and elemental iodine into the reaction bottle, carrying out a reaction at a normal temperature under normal pressure, carrying out extracting, merging organic phases, and carrying out concentrating, so as to obtain crude 1-(1-iodoethyl)-3-nitrobenzene; and S3. dissolving the crude 1-(1-iodoethyl)-3-nitrobenzene in a polar solvent, adding sodium borohydride in batches, carrying out a reaction at a normal temperature under normal pressure, carrying out extracting, merging organic phases, carrying out concentrating, carrying out reduced-pressure distillation, thereby obtaining pure 1-ethyl-3-nitrobenzene. According to the method for preparing the 1-ethyl-3-nitrobenzene, disclosed by the invention, the reaction conditions are mild, a preparation process and purificationsteps are safe and simple, the product yield is high, and thus, industrialization is convenient to achieve.
Chemoselective Hydrogenation with Supported Organoplatinum(IV) Catalyst on Zn(II)-Modified Silica
Camacho-Bunquin, Jeffrey,Ferrandon, Magali,Sohn, Hyuntae,Yang, Dali,Liu, Cong,Ignacio-De Leon, Patricia Anne,Perras, Frédéric A.,Pruski, Marek,Stair, Peter C.,Delferro, Massimiliano
, p. 3940 - 3951 (2018/03/29)
Well-defined organoplatinum(IV) sites were grafted on a Zn(II)-modified SiO2 support via surface organometallic chemistry in toluene at room temperature. Solid-state spectroscopies including XAS, DRIFTS, DRUV-vis, and solid-state (SS) NMR enhanced by dynamic nuclear polarization (DNP), as well as TPR-H2 and TEM techniques revealed highly dispersed (methylcyclopentadienyl)methylplatinum(IV) sites on the surface ((MeCp)PtMe/Zn/SiO2, 1). In addition, computational modeling suggests that the surface reaction of (MeCp)PtMe3 with Zn(II)-modified SiO2 support is thermodynamically favorable (ΔG = -12.4 kcal/mol), likely due to the increased acidity of the hydroxyl group, as indicated by NH3-TPD and DNP-enhanced 17O{1H} SSNMR. In situ DRIFTS and XAS hydrogenation experiments reveal the probable formation of a surface Pt(IV)-H upon hydrogenolysis of Pt-Me groups. The heterogenized organoplatinum(IV)-hydride sites catalyze the selective partial hydrogenation of 1,3-butadiene to butenes (up to 95%) and the reduction of nitrobenzene derivatives to anilines (up to 99%) with excellent tolerance of reduction-sensitive functional groups (olefin, carbonyl, nitrile, halogens) under mild reaction conditions.
Significance of surface oxygen-containing groups and heteroatom P species in switching the selectivity of Pt/C catalyst in hydrogenation of 3-nitrostyrene
Wu, Qifan,Zhang, Bin,Zhang, Chao,Meng, Xiangchun,Su, Xinluona,Jiang, Shan,Shi, Ruhui,Li, Yan,Lin, Weiwei,Arai, Masahiko,Cheng, Haiyang,Zhao, Fengyu
, p. 297 - 307 (2018/06/20)
The selectivity of 3-nitrostyrene (NS) hydrogenation over 0.5 wt-% Pt catalysts supported on carbon materials can be switched simply by changing reduction temperature. When the reduction temperature was 150 °C, 1-ethyl-3-nitrobenzene (ENB) was mainly produced in a selectivity of 93% at a conversion of 95% (at 100 °C). When the reduction was conducted at a higher temperature of 450 °C, in contrast, the main product was switched to 3-aminostyrene (AS) in a selectivity of 96% at a conversion of 91%. That is, the Pt/C catalysts reduced at low and high temperatures could preferentially catalyze the hydrogenation of vinyl and nitro groups of NS, respectively. This switching of the product selectivity may be ascribed to actions of surface oxygen-containing functional groups and surface hetero P species. The quantity and nature of these surface species were examined in detail by a few different methods. For the low-temperature reduced catalyst, surface acidic groups present close to Pt nanoparticles (～2 nm) would interact with the nitro group of a NS molecule and make its vinyl group more likely to interact with the surface active metal species of Pt nanoparticles; this facilitates the hydrogenation of the latter and produces ENB selectively. For the high-temperature reduced catalyst, however, P species would interact with Pt and form Pt-POx complex, on which a NS molecule is likely to be adsorbed with its nitro group, facilitating the selective production of AS via its hydrogenation. It is demonstrated that surface functional groups and surface hetero atoms (like P), in addition to main active metal species (like Pt), should have direct actions in the catalysis for such a catalyst that exposes a larger quantity of surface functional groups and/or hetero atoms compared to the number of supported metal nanoparticles.
Hollow carbon anchored highly dispersed Pd species for selective hydrogenation of 3-nitrostyrene: metal-carbon interaction
Lou, Yang,Xu, Jia,Wu, Honglu,Liu, Jingyue
supporting information, p. 13248 - 13251 (2018/12/11)
Constructing Pd-C bond between Pd particles and defective hollow nanocarbons (h-NCs) not only enables facile H2 dissociation but also diffusion of the dissociated H species, which makes the Pd/h-NC highly active with a TOF of 21?845 h?1 (>80 times higher than that of the best catalyst in literature), selective (97%), and stable (4 cycles) for selective hydrogenation of 3-nitrostyrene to 3-ethylnitrobenze.
Room-Temperature Chemoselective Reduction of 3-Nitrostyrene to 3-Vinylaniline by Ammonia Borane over Cu Nanoparticles
Shen, Mengqi,Liu, Hu,Yu, Chao,Yin, Zhouyang,Muzzio, Michelle,Li, Junrui,Xi, Zheng,Yu, Yongsheng,Sun, Shouheng
, p. 16460 - 16463 (2018/12/11)
We report a new strategy of controlling catalytic activity and selectivity of Cu nanoparticles (NPs) for the ammonia borane initiated hydrogenation reaction. Cu NPs are active and selective for chemoselective reduction of nitrostyrene to vinylaniline under ambient conditions. Their activity, selectivity, and more importantly, stability are greatly enhanced by their anchoring on WO2.72 nanorods, providing a room-temperature full conversion of nitrostyrene selectively to vinylaniline (>99% yield). Compared with all other catalysts developed thus far, our new Cu/WO2.72 catalyst shows much enhanced hydrogenation selectivity and stability without the use of pressured hydrogen. The synthetic approach demonstrated here can be extended to prepare various M/WO2.72 catalysts (M = Fe, Co, Ni), with M being stabilized for many chemical reactions.
