30107-43-8Relevant articles and documents
Preparation of 14C-labelled dimethylsilane-1,1-diol
Cella,Carpenter
, p. 427 - 430 (1994)
The preparation of 14C-labelled dimethylsilane-1,1-diol in two steps from 14C-labelled diphenyldimethylsilane is described. Aluminum chloride catalyzed protodesilylation of diphenyldimethyisilane with HCl in dichloromethane or dimethyldichlorosilane at 0-5°C affords labelled dimethyldichlorosilane which is hydrolyzed in the presence of triethylamine to afford the title compound in 45-60% yield.
Honeycomb-like CuO/ZnO hybrid nanocatalysts prepared from solid waste generated in the organosilane industry
Li, Jing,Liu, Hezhi,Ji, Yongjun,Zhang, Yu,Wang, Guangna,Zhu, Yongxia,Zhong, Ziyi,Hu, Xiao,Su, Fabing
, p. 59737 - 59748 (2016)
We report the preparation of honeycomb-like CuO/ZnO (CZx/y) nanocatalysts with CuO nanospheres (NSs) adhered with ZnO nanoparticles (NPs) for the Rochow reaction. The synthesis was carried out via adsorption of Cu2+/Zn2+ ions on carbon black (CB) which acted as both the agglomeration inhibitor and the hard template, and followed by calcination in air. The low cost Cu2+/Zn2+ ions were recovered from the solid waste generated in the organosilane industry via a simple ammonia leaching treatment. The samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and temperature-programmed reduction. The as-obtained CZx/y nanohybrids had a honeycomb-like structure with large voids and openings among the CuO NSs. When re-used as a Cu-based catalyst for the Rochow reaction, the CZx/y NPs sample with an optimized ratio showed significantly improved dimethyldichlorosilane (M2) selectivity and silicon (Si) conversion as compared with the CuO/ZnO NPs prepared in the absence of CB, discrete CuO or ZnO NPs and the CuO/ZnO NPs with different compositions, mainly due to the unique honeycomb-like structure, smaller crystal size and synergistic electronic effect at the interface between Cu and ZnO in CZx/y NPs.
Heterojunctions generated in SnO2-CuO nanocatalysts for improved catalytic property in the Rochow reaction
Zou, Shanying,Ji, Yongjun,Wang, Guangna,Zhu, Yongxia,Liu, Hezhi,Jia, Lihua,Guo, Xiangfeng,Zhong, Ziyi,Su, Fabing
, p. 63355 - 63362 (2015)
We report the improved catalytic performance of SnO2-CuO hybrid nanocatalysts synthesized by rationally designing and controlling the local heterojunction structure. The SnO2 nanoparticle (NP) decorated CuO nanorods (NRs) (SnO2-CuO) with a mace-like structure and with various CuO:SnO2 ratios were prepared via depositing pre-synthesized SnO2 NPs on CuO NRs in the presence of polyvinylpyrrolidone molecules. The CuO NRs were obtained by a facile hydrothermal reaction using Cu(NO3)2·3H2O as the precursor. The samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and temperature-programmed reduction analyses. The results indicated that in the SnO2-CuO hybrid nanostructures, the heterojunctions were well generated as the SnO2 NPs were well dispersed on the CuO NRs. Their catalytic performances were then explored via the Rochow reaction, in which solid silicon (Si) reacts with gaseous methyl chloride (MeCl) to produce dimethyldichlorosilane (M2). Compared to separate CuO and SnO2 as well as their physical mixture, the SnO2-CuO hybrids exhibit significantly enhanced M2 selectivity and Si conversion because of the enhanced synergistic interaction between SnO2 and CuO due to the generated heterojunctions. This work demonstrates that the performance of heterogeneous catalysts can be improved by carefully designing and controlling their structures even when their composition remains unchanged.
Synergistic effect in bimetallic copper-silver (CuxAg) nanoparticles enhances silicon conversion in Rochow reaction
Zhang, Zailei,Ji, Yongjun,Li, Jing,Zhong, Ziyi,Su, Fabing
, p. 54364 - 54371 (2015)
The oleylamine thermal reduction process was employed to prepare bimetallic copper-silver (CuxAg (0 ≤ x ≤ 50)) nanoparticles, such as Cu, Cu50Ag, Cu20Ag, Cu10Ag, Cu5Ag, CuAg, CuAg2, and Ag, by using Cu(CH3COO)2 and AgNO3 as the precursors. The samples were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The CuxAg hybrid nanostructure showed good particle dispersion, and Cu and Ag metals were well mixed. The catalytic properties of these bimetallic CuxAg nanoparticles as model catalysts for the Rochow reaction were explored. Compared to monometallic Cu and Ag nanoparticles, bimetallic CuxAg nanoparticles resulted in a much higher silicon conversion, which is attributed to the synergistic electronic effect between Cu and Ag metals. For example, the Cu atom was observed to have a lower electron density in the CuxAg bimetallic nanoparticle than that in monometallic Cu nanoparticles, which enhanced the formation of methylchlorosilanes on the silicon surface with chloromethane, demonstrating the significance of the CuxAg bimetallic catalysts in catalytic reactions during organosilane synthesis. The insights gained in this study should be conducive to the design of good Cu-based catalysts for the Rochow reaction.
Porous (CuO)xZnO hollow spheres as efficient Rochow reaction catalysts
Zhang, Zailei,Ji, Yongjun,Li, Jing,Zhu, Yongxia,Zhong, Ziyi,Su, Fabing
, p. 2808 - 2819 (2016)
Nowadays, how to achieve both high dimethyldichlorosilane selectivity and silicon conversion in the Rochow reaction still remains a major challenge in the organosilane industry, in which silicon and chloromethane are converted into methylchlorosilanes on Cu-based catalysts mixed with ZnO promoter. Therefore, this calls for the development of outstanding catalysts with both high activity and selectivity for the Rochow reaction and also for a deep fundamental understanding of the catalytic mechanism. In this work, we designed and synthesized a series of copper oxide-zinc oxide catalysts ((CuO)xZnO (0 ≤ x ≤ 49)) with a distinct porous hollow spherical structure for the reaction. These porous hollow spherical catalysts composed of CuO and ZnO nanoparticles were prepared through co-adsorption of Cu2+ and Zn2+ in the interior and outer surfaces of the hydrothermally synthesized carbonaceous spheres, followed by a new hydrothermal treatment and calcination in air. The catalytic properties of the (CuO)xZnO hollow spheres for dimethyldichlorosilane synthesis via the Rochow reaction was investigated, and a deeper understanding of the catalytic mechanism was obtained. As compared to pure CuO hollow spheres, the prepared (CuO)19ZnO hollow spheres exhibited much higher dimethyldichlorosilane selectivity and silicon conversion, which are clearly related to the synergistic electronic effect between Cu and ZnO and to the distinct catalyst structures which allow intimate contact of the reactant molecules with the active component and the efficient transport of the molecules. This work opens a new way for the fabrication of efficient and integrated Cu-based catalysts for the Rochow reaction.
Synthesis of dimethyldichlorosilane by catalytic disproportionation of methyltrichlorosilane over a H2SO4 activated chinese bentonite
Ao, Zhiyong,Zhang, Ning,Jian, Lijuan,Fu, Qiong,Zhang, Fang,Chen, Chao
, p. 2135 - 2144 (2011)
Disproportionation of methyltrichlorosilane (MTS) to produce dimethyldichlorosilane (DMCS) was firstly carried out over a bentonite from Zhejiang province (China) after H2SO4 activation. The results demonstrated that the bentonite activated with 30 wt% H 2SO4 solution exhibited an excellent activity with 92% conversion of MTS and 41% yield of DMCS at 673 K under atmospheric pressure. The catalysts were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray powder diffraction (XRD) and N2 absorption-desorption. The acidic sites of these bentonites were studied by in situ FTIR spectra of pyridine adsorption. It revealed that the coexistence of Lewis (L) and Bronsted (B) acidic sites facilitated the formation of DMCS and reaction temperature played important roles in the disproportionation reaction. Copyright Taylor & Francis Group, LLC.
Flower-like ZnO grown on urchin-like CuO microspheres for catalytic synthesis of dimethyldichlorosilane
Zhu, Yongxia,Wang, Yingli,Song, Lianying,Chen, Xin,Liu, Wuyuan,Sun, Jin,She, Xilin,Zhong, Ziyi,Su, Fabing
, p. 9794 - 9802 (2013)
We report the rational growth of flower-like ZnO on urchin-like CuO (f-ZnO@u-CuO) microspheres via a facile solvothermal method using copper nitrate and zinc nitrate as precursors in the presence of sodium nitrate and ethanol. A formation mechanism was proposed based on the observation of a series of reaction intermediates. The samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, inductively coupled plasma optical emission spectrometer, and temperature-programmed reduction. It was found that the morphology of the samples was highly dependent on the synthesis conditions, particularly the reaction time and the ammonia amount added. As a copper-based catalyst for dimethyldichlorosilane synthesis via the Rochow reaction, f-ZnO@u-CuO microspheres show better catalytic performance than the Cu-based catalysts physically mixed with ZnO promoter, probably because of the well-developed p-n heterojunction structures at the CuO and ZnO interfaces that generate a much strong synergistic effect. The work provides a simple method to synthesize hierarchical CuO/ZnO composites and would be helpful for understanding the catalytic mechanism of the Rochow reaction.
Catalytic disproportionation of methyltrichlorosilane by AL-MCM-41 to prepare dichlorodimethylsilane
Fu, Qiong,Zhang, Ning,Zhang, Jun,Hong, Sanguo
, p. 1183 - 1194 (2012)
Al-MCM-41 samples with various Si/Al ratios were prepared and then used to disproportionate methyltrichlorosilane (MTS) to produce dichlorodimethylsilane (DMCS). The catalysts were characterized by FT-IR, X-ray powder diffraction (XRD), 27Al magic angle spinning nuclear magnetic resonance ( 27Al MAS NMR), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and N2 absorption-desorption. It reveals that all samples show the hexagonal structure of MCM-41 and exhibit large BET surface areas (over 842m2g1). FT-IR spectra of pyridine adsorption demonstrates that Al-MCM-41 samples have Lewis (L) and Brnsted (B) acidic sites, and the B acidic sites are stable in the temperature ranging from 423 to 623K. The effects of aluminum content and temperature on the disproportionation reaction were also investigated. The results show that the Al-MCM-41 with the Si/Al ratio of 15:1 exhibits an excellent activity with 100% conversion of MTS and 47% selectivity of DMCS at 623K under atmospheric pressure. Taylor and Francis Group, LLC.
Controllable wet synthesis of multicomponent copper-based catalysts for Rochow reaction
Zhai, Yanzhao,Ji, Yongjun,Wang, Guangna,Zhu, Yongxia,Liu, Hezhi,Zhong, Ziyi,Su, Fabing
, p. 73011 - 73019 (2015)
This work aims to provide a facile, low-cost and scalable method for the preparation of multicomponent Cu-Cu2O-CuO catalysts, which are of high interest to the organosilane industry. A series of submicrometer-sized and Cu-based catalysts containing CuO, Cu2O and Cu, or some combination of them, were synthesized by a simple low-temperature wet chemical method using CuSO4·5H2O as the precursor and N2H4·H2O as a reducing agent. The samples were characterized by X-ray diffraction, thermogravimetric analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy techniques. It was observed that the composition of the samples could be tailored by varying the amount of reducing agent at a given reaction temperature and time. These catalysts were then tested in the Rochow reaction, using silicon powder and methyl chloride (MeCl) as reactants to produce dimethyldichlorosilane (M2), which is the most important organosilane monomer in the industry. Compared with bare CuO and Cu particles, the ternary CuO-Cu2O-Cu catalyst displayed much improved M2 selectivity and Si conversion, which can be attributed to the smaller copper particle size and the synergistic effect among the different components in the CuO-Cu2O-Cu catalyst. This catalyst preparation method is expected to yield efficient and low-cost copper catalysts for the organosilane industry.
Reactions of chlorinated vinylsilanes with hydrogen chloride
Lakhtin, V. G.,Ryabkov, V. L.,Kisin, A. V.,Nosova, V. M.,Chernyshev, E. A.
, p. 375 - 378 (1999)
Catalytic hydrochlorination of a series of chloro(chlorovinyl)methylsilanes was studied. The course of the reaction depends on the number and position of the chlorine atoms in the initial monomers.
