111-49-9Relevant articles and documents
Reductive amination of 1,6-hexanediol with Ru/Al2O3 catalyst in supercritical ammonia
Li, Yan,Cheng, Haiyang,Zhang, Chao,Zhang, Bin,Liu, Tong,Wu, Qifan,Su, Xinluona,Lin, Weiwei,Zhao, Fengyu
, p. 920 - 926 (2017)
Hexamethylenediamine (HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an environmental friendly route to produce HMDA via catalytic reductive amination of 1,6-hexanediol (HDO) in the presence of hydrogen. The activities of several heterogeneous metal catalysts such as supported Ni, Co, Ru, Pt, Pd catalysts were screened for the present reaction in supercritical ammonia without any additives. Among the catalysts examined, Ru/Al2O3 presented a high catalytic activity and highest selectivity for the desired product of HMDA. The high performance of Ru/Al2O3 was discussed based on the Ru dispersion and the surface properties like the acid-basicity. In addition, the reaction parameters such as reaction temperature, time, H2 and NH3 pressure were examined, and the reaction processes were discussed in detail.
Improved catalytic performance of acid-activated sepiolite supported nickel and potassium bimetallic catalysts for liquid phase hydrogenation of 1,6-hexanedinitrile
Lv, Yang,Hao, Fang,Liu, Pingle,Xiong, Shaofeng,Luo, He'an
, p. 15 - 23 (2017)
Different inorganic acids were used to activate sepiolite, and the acid-activated sepiolites supported nickel and potassium bimetallic catalysts were prepared. Nitrogen adsorption-desorption, hydrogen chemisorption, ammonia temperature programmed desorption (NH3-TPD), temperature programmed reduction (TPR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and energy dispersive X-ray (EDX) were used to characterize the catalysts. The catalytic performance of the acid-activated sepiolite supported K-Ni bimetallic catalysts were investigated in 1,6-hexanedinitrile (HDN) hydrogenation in liquid phase. It was revealed that the potassium could increase the alkalinity of the catalyst with the aim of inhibiting the formation of the 1-azacycloheptane (ACH). And the addition of potassium reduces the particle size of nickel and improves its dispersion. Compared with hydrochloric acid and sulfuric acid, nitric acid treatment increases more silanol groups (Si[sbnd]OH) on the sepiolite surface, which is helpful to nickel particles adsorption and dispersion. Nitric acid activated sepiolite supported nickel and potassium bimetallic catalysts (K-Ni/NASEP) present the best catalytic performance, the conversion of HDN comes up to 92.0% under moderate conditions of lower temperature and pressure, the selectivity to 6-aminocapronitrile (ACN) and 1,6-hexanediamine (HDA) is up to 95.2%.
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Ziegler,Orth
, p. 1867,1871 (1933)
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Liquid phase hydrogenation of adiponitrile over directly reduced Ni/SiO2 catalyst
Jia, Zekun,Zhen, Bin,Han, Minghan,Wang, Chengqiang
, p. 80 - 83 (2016)
Liquid phase hydrogenation of adiponitrile (ADN) to 6-aminocapronitrile (ACN) and hexamethylenediamine (HMD) was investigated on Ni/SiO2 catalysts prepared under different conditions. In this reaction, the highly reactive imine intermediate forms condensation byproducts by reacting with the primary amine products (ACN and HMD). A highly dispersed Ni/SiO2 catalyst prepared by the direct reduction of Ni(NO3)2/SiO2 was found to suppress the condensation reactions by promoting the hydrogenation of adsorbed imine, and it gave excellent hydrogenation activity and primary amine selectivity. Addition of NaOH increased the primary amine selectivity to 79% at the ADN conversion of 86%.
Surface Characterization and Hydrogenation Properties of Several Nickel/α-Alumina Catalysts
Medina, Francisco,Salagre, Pilar,Sueiras, Jesus-Eduardo,Fierro, Jose-Luis-Garcia
, p. 3507 - 3512 (1993)
Studies of the chemical preparation, X-ray photoelectron spectra (XPS), activation energies of reduction, temperature-programmed reduction (TPR), X-ray diffraction (XRD) and catalytic activities of several nickel/α-alumina catalysts have been caried out for the catalytic hydrogenation of hexanedinitrile, in a continuous process at 1 atm pressure, 443 K, and in the absence of ammonia.XPS results show complete reduction of non-stoichiometric NiO on α-alumina at temperatures higher than 623 K and higher surface nickel dispersion with increasing nickel content anddecreasing reduction temperatures.Activation energies of reduction for the α-alumina-supported non-stoichiometric NIO were higher than those of the unsupported non-stoichiometric NiO.TPR results show that the initial and final temperatures of reduction of the α-alumina-supported nonstoichiometric NiO are higher with unsupported NiO, confirming the inhibiting effect of α-alumina on NiO reduction.XRD measurements show the presence of α-alumina, NiO and Ni phases, and also the increase in crystallite size with increasing reduction temperature.Catalytic conversions increase with the nickel content and selectivities toward 6-aminohexanenitrile increase at lower nickel contents, high space velocities, and higher metallic sintering, probably owing to the presence of a higher content of specific crystal sites responsible for the production of 6-aminohexanenitrile.A mechanism is proposed.
METHOD FOR PRODUCING HEXAMETHYLENE DIAMINE
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Paragraph 0033-0055, (2021/02/13)
To provide a method for producing hexamethylene diamine from 1,6-hexanediol and ammonia, under easy-to-control mild conditions.SOLUTION: A method for producing hexamethylene diamine includes reacting 1,6-hexanediol with ammonia in the presence of a solvent by means of a noble metal-supporting catalyst.SELECTED DRAWING: None
One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
Coeck, Robin,De Vos, Dirk E.
supporting information, p. 5105 - 5114 (2020/08/25)
The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
