- Reduction of 2,4,6-trinitrotoluene by iron metal: Kinetic controls on product distributions in batch experiments
-
The reaction kinetics and product distributions for the reduction of 2,4,6-trinitrotoluene (TNT) by granular iron metal (Fe0) were studied in batch experiments under a variety of initial concentrations of TNT and Fe0. Although the kinetics of TNT disappearance were found to behave in accord with the standard theory for surface-mediated reactions, a complex relationship was found between the initial concentrations of TNT and Fe 0 and the appearance of the expected nitro reduction product, 2,4,6-triaminotoluene (TAT). TNT was completely converted to TAT only when the initial concentration of TNT was low and/or the initial concentration of Fe 0 was high. Mathematical analysis of a range of generic reaction schemes that produce stable end products in addition to TAT showed that (i) surface complexation of TAT is insufficient to describe all of our data and (ii) polymerization reactions involving TAT and/or various reaction intermediates are the likely source of the incomplete conversion of TNT to TAT at high initial TNT concentration and low Fe0 concentration. The relationship between TAT production and reaction conditions is shown to imply that passivation due to reaction products is more likely when the ratio of initial TNT concentration to Fe0 concentration is high and, therefore, that passivation rates observed at the laboratory scale are likely to be faster than those which would be observed at the field scale.
- Bandstra, Joel Z.,Miehr, Rosemarie,Johnson, Richard L.,Tratnyek, Paul G.
-
-
Read Online
- Novel preparation method of insensitive explosive TATB
-
The invention provides a novel preparation method of an insensitive explosive TATB. The method comprises the following steps: 1, with 2,4,6-trinitrotoluene as a raw material, subjecting 2,4,6-trinitrotoluene to reacting with hydrogen and acetic anhydride in sequence to obtain 2,4,6-triacetylaminotoluene; 2, subjecting the obtained 2,4,6-triacetylaminotoluene o oxidation and a decarboxylation reaction to obtain 1,3,5-triacetylaminobenzene; and 3, carrying out nitrification and hydrolysis reactions on the obtained 1,3,5-triacetylaminobenzene to obtain 2,4,6-trinitro-1,3,5-triaminobenzene. According to the invention, the raw material used in the preparation method is the cheap 2,4,6-trinitrotoluene, and used reactants or catalysts are commonly used products in the chemical industry, so the preparation method has characteristics of low cost and usage of simple and easily available raw materials. In addition, the preparation method also has the characteristics of short synthesis steps, simple operation of each step, high yield, high reaction rate, easy separation and collection of intermediate and final products and the like, and is beneficial for realization of mass production of TATB.
- -
-
Paragraph 0055; 0057-0073
(2020/12/10)
-
- Preparation method of 2,4,6-toluene triisocyanate
-
The invention provides a preparation method of 2,4,6-toluene triisocyanate, which comprises the steps of 1, under the catalytic action of nitrogen-doped porous carbon supported palladium, taking 2,4,6-trinitrotoluene as a raw material to obtain 2,4,6-triaminotoluene hydrochloride; and 2, taking 2,4,6-triaminotoluene hydrochloride as a raw material, and carrying out phosgenation reaction and reduced pressure distillation to prepare 2,4,6-toluene triisocyanate. The catalyst nitrogen-doped porous carbon loaded palladium adopted by the invention has the characteristics of simple preparation, low palladium loading capacity, efficient catalysis and reusability, and the production cost can be obviously reduced. Each step has the advantages of simple operation, high reaction conversion rate, easyseparation and collection of intermediate and final products, and the like. The preparation method has the advantage of low overall difficulty. Moreover, all intermediate products in the method are high in reaction activity, can be fully reacted, have few by-products, and are more beneficial to realizing high-quality production of 2,4,6-toluene triisocyanate.
- -
-
Paragraph 0084; 0090-0091; 0094; 0099-0100; 0130; 0135; 0137
(2021/01/04)
-
- Catalytic Paper Spray Ionization Mass Spectrometry with Metal Nanotubes and the Detection of 2,4,6-Trinitrotoluene
-
Materials are making inroads into mass spectrometry, and an example is the use of advanced materials for enhanced ionization by transformation of a less-ionizable molecule to an easily ionizable one. Here we show the use of Pt nanoparticle-decorated nanotubes as highly active catalysts for the reduction of 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene and subsequent easy detection of the product by in situ ambient ionization mass spectrometry.
- Sarkar, Depanjan,Som, Anirban,Pradeep, Thalappil
-
p. 11378 - 11382
(2019/03/26)
-
- Catalytic hydrogenation of nitrophenols and nitrotoluenes over a palladium/graphene nanocomposite
-
We report a stable palladium/graphene (Pd/G) nanocomposite with differing Pd content for use in the catalytic hydrogenation of nitrophenols and nitrotoluenes. Various microscopic and spectroscopic techniques were employed to characterize the as-prepared catalysts. Catalytic hydrogenation reactions of nitrophenols were conducted in aqueous solution by adding NaBH4, while the nitrotoluene hydrogenation was carried out in methanol in the presence of H2 because of the poor solubility in water. The Pd/G hybrids exhibited much higher activity and higher stability than the commercial Pd/C. Due to the presence of a large excess of NaBH4 compared to p-nitrophenol, the kinetic data can be explained by the assumption of a pseudo-first-order reaction with regard to p-nitrophenol. The resulting high catalytic activity can be attributed to the graphene sheets' strong dispersion effect for Pd nanoparticles and good adsorption ability for nitrobenzene derivatives via π-π stacking interactions. A plausible mechanism is proposed. Considering inductive and conjugation effects that may affect the reactions, the reactivity of nitrophenols in this study is expected to follow the order m-NP > o-NP > p-NP > 2,4-DNP > 2,4,6-TNP, which is in good agreement with the experimental results. This journal is the Partner Organisations 2014.
- Sun, Jingwen,Fu, Yongsheng,He, Guangyu,Sun, Xiaoqiang,Wang, Xin
-
p. 1742 - 1748
(2014/06/09)
-
- In situ formed metal nanoparticle systems for catalytic reduction of nitroaromatic compounds
-
Developing robust and facile catalytic systems for converting nitroaromatic compounds to NH2-containing compounds are of importance to decrease or even eliminate their toxicity or risk in the environment. In view of in situ formed metal nanoparticles, the metal ion (Cu2+, Ag+, AuCl4-, Co2+ and Ni2+)/NaBH4 systems were employed to catalyze the reduction reaction of nitroaromatic compounds. By employing the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a model reaction, the effects of concentration of NaBH4, 4-NP and metal ions on the rate constants of the catalytic reduction reactions were systematically investigated. Apparent activation energies of these metal ion/NaBH4 catalytic systems were further measured and compared. In situ formed metal NPs could be characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Furthermore, these metal ion/NaBH4 systems were successfully employed to catalyze the reduction reaction of a series of other nitroaromatic compounds. These metal ion/NaBH4 catalytic systems investigated in this protocol are simple and do not require the preparation of metal nanoparticles in advance, compared with previous related reports. This journal is
- Wu, Xiao-Qiong,Wu, Xing-Wen,Shen, Jiang-Shan,Zhang, Hong-Wu
-
p. 49287 - 49294
(2014/12/11)
-
- Voltammetry study of the 2,4,6-trinitrotoluene conversion into the amine compounds using zero-valent iron
-
The paper describes the use of voltammetry in monitoring the reductive process of 2,4,6-trinitrotoluene (TNT) to amine compounds by zero-valent iron. This method to simultaneously determine the reduction of TNT and the increase of Fe2+ concentrations in the samples. The method may be applied to establish the efficiency of the conversion process of TNT, the role of zero-valent iron and its efficiency in the reductive process. The factors such as pH, TNT concentration, reaction times and Fe(0) mass influencing on the conversion process into amine compounds have been studied.
- Quoc Trung, Le,Van Bay, Dao,Minh, Do Binh,Luong, Tran Duc,Van Chung, Tran
-
experimental part
p. 3137 - 3139
(2012/02/05)
-
- Effect of adsorption to elemental iron on the transformation of 2,4,6-trinitrotoluene and hexahydro-1,3,5-trinitro-1,3,5-triazine in solution
-
The effect of adsorption to elemental iron on the reductive transformation of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (royal demolition explosive [RDX]) in aqueous solution was studied with scrap iron and high-purity iron. In batch experiments with the same total iron surface area and a mixing rate of 100 rpm, TNT and RDX were removed from the solution within 30 min. With high-purity iron, adsorbed TNT was reduced to 2,4,6-triaminotoluene (TAT) rapidly, with little accumulation of intermediates at the surface. With scrap iron, the extent of adsorption of TNT and its daughter products was more significant and reduction of these adsorbed molecules to TAT was slower. Distribution of the intermediates indicated that the reaction with scrap iron occurred primarily through reduction of the ortho nitro group. Kinetic analysis suggests that mass transfer or adsorption of TNT controlled the overall rate of TNT reduction to TAT with pure iron, whereas with scrap iron, the rate of TAT formation was probably limited by other processes. Compared to TNT, transformation of adsorbed RDX was more rapid and less affected by iron type. The RDX was reduced to an unidentified, water-soluble intermediate and NH4+, which accounted for approximately 50% of the RDX nitrogen. No total organic carbon reduction was observed before and after RDX transformation with scrap iron.
- Oh, Seok-Young,Cha, Daniel K.,Kim, Byung J.,Chiu, Pei C.
-
p. 1384 - 1389
(2007/10/03)
-