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Rhodium-catalyzed borylative carbon monoxide reduction to gem-diborylmethane

2021, Xua, Jian-Xing, Wu, Fu-Peng, Wu, Xiao-Feng

Herein, we developed a rhodium-catalyzed reduction of CO with bis(pinacolato)diboron (B2pin2) under atmospheric pressure of CO with silane as the hydride source, gem-diborylmethane [H2C(Bpin)2] as a versatile and fundamental C1 compound can be formed. Notably, this is the first example on transition metal-catalyzed borylation of CO. © 2020 The Author(s)

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Monodisperse nickel-nanoparticles for stereo- and chemoselective hydrogenation of alkynes to alkenes

2019, Murugesan, Kathiravan, Alshammari, Ahmad S., Sohail, Manzar, Beller, Matthias, Jagadeesh, Rajenahally V.

Here, we report the use of monosaccharides for the preparation of novel nickel nanoparticles (NP), which constitute selective hydrogenation catalysts. For example, immobilization of fructose and Ni(OAc)2 on silica and subsequent pyrolysis under inert atmosphere produced graphitic shells encapsulated Ni-NP with uniform size and distribution. Interestingly, fructose acts as structure controlling compound to generate specific graphitic layers and the formation of monodisperse NP. The resulting stable and reusable catalysts allow for stereo- and chemoselective semihydrogenation of functionalized and structurally diverse alkynes in high yields and selectivity. © 2019 The Author(s)

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Decomposition of methane over alumina supported Fe and Ni–Fe bimetallic catalyst: Effect of preparation procedure and calcination temperature

2016, Al-Fatesh, A.S., Fakeeha, A.H., Ibrahim, A.A., Khan, W.U., Atia, H., Eckelt, R., Seshan, K., Chowdhury, B.

Catalytic decomposition of methane has been studied extensively as the production of hydrogen and formation of carbon nanotube is proven crucial from the scientific and technological point of view. In that context, variation of catalyst preparation procedure, calcination temperature and use of promoters could significantly alter the methane conversion, hydrogen yield and morphology of carbon nanotubes formed after the reaction. In this work, Ni promoted and unpromoted Fe/Al2O3 catalysts have been prepared by impregnation, sol–gel and co-precipitation method with calcination at two different temperatures. The catalysts were characterized by X-ray diffraction (XRD), N2 physisorption, temperature programmed reduction (TPR) and thermogravimetric analysis (TGA) techniques. The catalytic activity was tested for methane decomposition reaction. The catalytic activity was high when calcined at 500 °C temperature irrespective of the preparation method. However while calcined at high temperature the catalyst prepared by impregnation method showed a high activity. It is found from XRD and TPR characterization that disordered iron oxides supported on alumina play an important role for dissociative chemisorptions of methane generating molecular hydrogen. The transmission electron microscope technique results of the spent catalysts showed the formation of carbon nanotube which is having length of 32–34 nm. The Fe nanoparticles are present on the tip of the carbon nanotube and nanotube grows by contraction–elongation mechanism. Among three different methodologies impregnation method was more effective to generate adequate active sites in the catalyst surface. The Ni promotion enhances the reducibility of Fe/Al2O3 oxides showing a higher catalytic activity. The catalyst is stable up to six hours on stream as observed in the activity results.

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The Exploration of Aroyltrimethylgermane as Potent Synthetic Origins and Their Preparation

2019, Yuan, Yang, Zhang, Youcan, Chen, Bo, Wu, Xiao-Feng

The synthetic utilities of acylgermanes are surprisingly rarely explored compared with their analogues. In this communication, the survey of aroyltrimethylgermane as potent synthetic origins has been studied. A variety of novel chemical transformations have been realized, including using the acylgermane group as a directing group in Rh-catalyzed aromatic C-H alkenylation reaction and Ir-catalyzed aromatic C-H amidation reactions. Additionally, a general approach for acylgermanes preparation has been established as well. The catalytic system proceeds effectively in the presence of Pd(OAc)2/BINOL-based monophosphite (L11) and allows for the straightforward access to a wide range of functionalized acylgermanes in high yields. © 2019 The Author(s)Catalysis; Organic Synthesis; Organic Reaction; Chemical Synthesis © 2019 The Author(s)

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ZnO Nanoparticles Encapsulated in Nitrogen-Doped Carbon Material and Silicalite-1 Composites for Efficient Propane Dehydrogenation

2019, Zhao, Dan, Li, Yuming, Han, Shanlei, Zhang, Yaoyuan, Jiang, Guiyuan, Wang, Yajun, Guo, Ke, Zhao, Zhen, Xu, Chunming, Li, Ranjia, Yu, Changchun, Zhang, Jian, Ge, Binghui, Kondratenko, Evgenii V.

Chemistry; Catalysis; Nanoparticles © 2019 The Author(s)Non-oxidative propane dehydrogenation (PDH)is an attractive reaction from both an industrial and a scientific viewpoint because it allows direct large-scale production of propene and fundamental analysis of C-H activation respectively. The main challenges are related to achieving high activity, selectivity, and on-stream stability of environment-friendly and cost-efficient catalysts without non-noble metals. Here, we describe an approach for the preparation of supported ultrasmall ZnO nanoparticles (2–4 nm, ZnO NPs)for high-temperature applications. The approach consists of encapsulation of NPs into a nitrogen-doped carbon (NC)layer in situ grown from zeolitic imidazolate framework-8 on a Silicalite-1 support. The NC layer was established to control the size of ZnO NPs and to hinder their loss to a large extent at high temperatures. The designed catalysts exhibited high activity, selectivity, and on-stream stability in PDH. Propene selectivity of about 90% at 44.4% propane conversion was achieved at 600°C after nearly 6 h on stream. © 2019 The Author(s)