Nitrogen-rich Material Research Articles

First-principle calculations of the electronic, vibrational, and thermodynamic properties of nitrogen-rich salt of 3,6-dinitramino-1,2,4,5-tetrazine [(NH4)2(DNAT)

Energy-containing materials such as explosives have attracted considerable interest recently. In the field of high-energy materials, tetrazine and its derivatives can largely meet the requirements of high nitrogen content and oxygen balance. Nitrogen-rich energetic salts are important research subjects. Nitrogen-rich salt of 3,6-dinitramino-1,2,4,5-tetrazine is a high-energy nitrogen-rich material, but there are few related studies. This paper systematically studies the crystal structure and electronic, vibrational, and thermodynamic properties of (NH4)2(DNAT). The lattice parameters of (NH4)2(DNAT) are observed to align well with the experimental values. The properties of electrons are analyzed by band structure and density of states (DOS). The phonon dispersion curves indicate that the compound is dynamically stable. The vibrational modes of bonds and chemical groups are described in detail, and the peaks in the Raman and infrared spectra are assigned to different vibration modes. Based on the vibration characteristics, thermodynamic properties such as enthalpy (H), Helmholtz free energy (F), entropy (S), Gibbs free energy (G), constant volume heat capacity (CV), and Debye temperature (Θ) are analyzed. This article can pave the way for subsequent work or provide data support to other researchers, promoting further research. In this study, we utilized the density functional theory (DFT) for our calculations. The exchange-correlation potential and van der Waals interactions were characterized based on the GGA-PBE + G function calculation. We obtained Brillouin zone integrals using Monkhorst-Pack k-point grids, with the k-point of the Brillouin zone set to a 2 × 2 × 2 grid. During the self-consistent field operation, we set the total energy convergence tolerance to 5 × 10-6eV per atom. The cut-off energy for the calculation was established at 830eV. Additionally, the states of H (1s1), C (2s2 2p2), N (2s2 2p3), and O (2s2 2p4) were treated as valence electrons in our study.

Cu single atoms regulating nitrogen active-sites of g-C3N4 for sodium ion storage

Nitrogen-rich material of graphitic carbon nitride (g-C3N4) with cost-effectiveness and easy accessibility has been considered as one of the most promising anode materials for sodium ion batteries (SIBs). However, the excessive presence of non-stable nitrogen sites in low crystallinity carbon nitrides would result in significant irreversibility, inadequate ion conductivity and structural instability, thereby limiting its practical application. Herein, a novel low-temperature strategy is proposed to stabilize the g-C3N4 by modulating the nitrogen configuration with single-atoms copper. The formed copper single atoms serving as anchors effectively regulate the coordination environment of nitrogen atoms in carbon nitride, thereby constructing stable nitrogen active sites for Na+ storage and conductive networks for rapid Na+ transport. Therefore, the Cu1.0/NC exhibits superior capacity (350.4 mAh g−1 at 50 mA g−1), exceptional rate performance (252.3 mAh g−1 at 1000 mA g−1), and long-cycle stability (capacity retention rate of 80.3 % after 1000 cycles at 5A g−1). Furthermore, in-situ Raman, ex-situ XANES and XPS technologies jointly reveal that the Cu atoms significantly influence the charge transfer process of Na+ and change the storage mode of sodium through redox effects during the sodiation/desodiation process. This work proves that single-atom engineering is a novel and feasible strategy to optimize the high-performance electrode materials for rechargeable batteries.

Synthesis of C-C bonded trifluoromethyl-based high-energy density materials via the ANRORC mechanism.

A trifluoromethyl group substituted C-C bonded nitrogen rich energetic material 3-(3-nitro-1H-pyrazol-4-yl)-5-(trifluoromethyl)-1,2,4-oxadiazole (4), its hydroxyl amine (5) and 3,6,7-triamino-7H-[1,2,4]triazolo[4,3-b][1,2,4]triazol-2-ium (6) salts and hydrazinium 5-(3-nitro-1H-pyrazol-4-yl)-3-(trifluoromethyl)-1,2,4-triazol-1-ide (7) were synthesized and fully characterized using infrared spectroscopy (IR), multinuclear magnetic resonance (NMR) spectroscopy (1H, 13C, and 19F), high-resolution mass spectrometry (HRMS), elemental analysis (EA) and differential scanning calorimetry (DSC) studies. Furthermore, compounds 4 and 7 were confirmed using single-crystal X-ray diffraction studies (SC-XRD). All compounds possess good density (1.70-1.80 g cm-3), detonation velocity (6432-7144 m s-1), pressure (16.38-20.31 GPa), and thermal stability (>170 °C). They are insensitive towards mechanical stimuli, impact (IS > 35 J) and friction (FS > 288 N). Overall, due to their balanced performance, these compounds can be a better replacement for presently used explosives such as trinitrotoluene (TNT).

Influx of nitrogen-rich material from the outer Solar System indicated by iron nitride in Ryugu samples

Large amounts of nitrogen compounds, such as ammonium salts, may be stored in icy bodies and comets, but the transport of these nitrogen-bearing solids into the near-Earth region is not well understood. Here, we report the discovery of iron nitride on magnetite grains from the surface of the near-Earth C-type carbonaceous asteroid Ryugu, suggesting inorganic nitrogen fixation. Micrometeoroid impacts and solar wind irradiation may have caused the selective loss of volatile species from major iron-bearing minerals to form the metallic iron. Iron nitride is a product of nitridation of the iron metal by impacts of micrometeoroids that have higher nitrogen contents than the CI chondrites. The impactors are probably primitive materials with origins in the nitrogen-rich reservoirs in the outer Solar System. Our observation implies that the amount of nitrogen available for planetary formation and prebiotic reactions in the inner Solar System is greater than previously recognized.

Preparation of Fe, N co-doped oxygen reduction catalysts from sacrificial templates and their application to Zn-air batteries

Fe, N co-doped non-precious metal oxygen reduction catalysts has been prepared with nitrogen-rich precursor material (g-C3N4) as a self-sacrificing template and N source. The utilization of g-C3N4 as a nitrogen-rich material could anchor the Fe source sufficiently on its surface, and form abundant active sites. The g-C3N4-derived carbon has a high specific surface area, which facilitates the more active sites to be exposed, and the suitable pore structure provides a site for the oxygen reduction reaction. The half-wave potential of the catalyst is optimized to 0.85 V by doping with different Fe-content sources, exceeding that of commercial 20% Pt/C catalysts. The prepared catalysts also exhibit excellent electron transfer numbers along with superior methanol resistance. The prepared catalysts is loaded into Zn-Air battery devices and presenting high open-circuit voltage, power density, and specific capacitance performance. This work provides an economical and feasible preparation strategy to explore nitrogen-rich precursor materials as Fe-N-C type efficient oxygen reduction catalysts.

Catalytic thermal decomposition of ammonium perchlorate by a series of lanthanide EMOFs

Given their unique and excellent properties, metal–organic frameworks (MOFs) materials have been used in many scientific fields. EMOFs use energetic materials as ligands, which can provide part of the energy for the system while catalyzing ammonium perchlorate. The energetic material 1.1′-dihydroxyazotetrazole (H2AzTO), as a high-energy nitrogen-rich material, was selected as a ligand. Five kinds of La3+, Ce3+, Pr3+, Nd3+, and Sm3+ lanthanide EMOFs were synthesized and obtained. Single crystal X-ray diffraction tests were conducted to obtain the crystal structures of EMOFs 1–5, which indicate that they have similar crystal structures. The thermal stabilities of EMOFs 1–5, which are obtained by differential scanning calorimetry (DSC) tests, are improved compared with that of the ligand. The results of thermic-decomposition of ammonium perchlorate (AP) and AP mixtures with 10 wt% EMOFs 1–5 show that except for AP mixed with 10 wt% compound 2, the high-temperature decomposition peak temperature of AP mixed with other compounds is significantly advanced (up to 59.3–88.3 K), and the decomposition of AP is continuous and violent. EMOFs 3–5 have good application prospects for the catalytic thermic-decomposition of AP.

Microbial biosignature preservation in carbonated serpentine from the Samail Ophiolite, Oman

Serpentinization is a geological process involving the interaction of water and ultramafic rock, the chemical byproducts of which can serve as an energy source for microbial communities. Although serpentinite systems are known to host active microbial life, it is unclear to what extent fossil evidence of these communities may be preserved over time. Here we report the detection of biosignatures preserved in a mineralized fracture within drill cores from the Samail Ophiolite in Oman. Two varieties of filamentous structures were identified in association with iron oxide precipitates. The first type are interpreted as likely microbial remains, while the second type are recognized as potentially microbiological dubiofossils. Additionally, laminated structures composed of carbon and nitrogen rich material were identified and interpreted as having a microbially-associated origin. Our observations affirm the potential to detect subsurface microbial communities within serpentinizing environments and highlight a unique taphonomic window to preserve evidence of rock-hosted life.

Insensitive nitrogen-rich compounds with a planar 2D configuration based on an imidazole–tetrazole

A planar nitrogen rich energetic material, NABTI, with layered molecular stacking was synthesized by a simple method.

Some Nitrogen Rich Energetic Material Synthesis by Nucleophilic Substitution Reaction from Polynitro Aromatic Compounds.

Three new nitrogen-rich energetic compounds, N-(5-chloro-2,4-dinitrophenyl)hydrazine (1), N-(5-chloro-2,4-dinitrophenyl)guanidine (2) and N-(5-chloro-2,4-dinitrophenyl)-4-aminopyrazole (3) prepared by the nucleophilic substitution reaction of 1,3-dichloro-4,6-dinitrobenzene with hydrazine, guanidinium carbonate and 4-aminopyrazole. The compounds were characterized by 1H NMR, 13C NMR, IR and mass spectroscopy. Only compound 2 could be prepared in a suitable crystal and molecular model was determined by X-ray analysis. Compounds were investigated by TG and DSC. Thermal degradation and thermokinetic behavior were investigated by Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose techniques. Compounds were observed to be prone to exothermical thermal decomposition. HOMO and LUMO levels, theoretical formation enthalpy and electrostatic maps were calculated by Gaussian09. The detonation velocity and pressure were calculated by Kamlet-Jacobs equation. The compounds were assayed for antimicrobial properties.

Boosting the ultrahigh initial coulombic efficiency of porous carbon anodes for sodium-ion batteriesvia in situfabrication of a passivation interface

In this study we have prepared a nitrogen and oxygen rich porous carbon material (NOPC) and designed a uniform passivation layer of CMC on the material by using a one-step method, which suppresses the decomposition of electrolytes and results in an excellent ICE of 90%.

Spruce bark beetles as a biological waste that can be processed in a biogas plant

Biogas plays an important role in reducing the amount of biowaste that is converted to methane which is usable by multiple pathways in the energy sector. Bark beetles are among the most important pests of spruce forests in Europe. Principal measures of managing bark beetle populations include trapping them with pheromone traps. Biomass of bark beetles collected by the traps constitutes a waste of forest resources that could potentially be processed in biogas plants. The aim of this study was to provide information about the trapping of bark beetles by pheromone traps in Tatra National Park during 2005-2018 and to verify the energy potential of a combination of liquid digestate and bark beetle biomass collected by pheromone traps. The bark beetle biomass is a seasonal smallvolume nitrogen-rich material which could be processed at agricultural biogas plants. The biochemical methane potential batch test performed at 40 °C showed a high degree of digestion of milled beetles within 40 days, with a methane production of 0.242 Nm3 per kilogram of total solids (TS). The single-stage low-solids mesophilic fed-batch anaerobic digestion of untreated beetles was carried out in a lab-scale rotary drum reactor. Within 52 days, the average organic loading rate was 1.019 kg VS m-3 day-1, where VS stands for volatile solids. The specific biogas and methane production reached 0.218 Nm3 kg-1 TS and 0.140 Nm3 kg-1 TS,respectively. The cuticles of the beetle bodies were not obviously disturbed by the fermentation process. The digestate was quite rich in nitrogen, but the other element contents did not differ too much from fertilizer made from manure or phytomass.

Adsorption selectivity of CO2 over CH4, N2 and H2 in melamine\u2013resorcinol\u2013formaldehyde xerogels

Sorptive selectivity of melamine–resorcinol–formaldehyde xerogels, towards CO2, CH4, N2 and H2, is reported, where all systems demonstrate potential for selective adsorption of CO2 from corresponding binary gas mixtures. Selected gas mixtures represent important gas separation applications found in industry, i.e. CO2 removal from power plant flue gases (CO2–N2), sour gas sweetening (CO2–CH4), and separation of species in the water–gas shift reaction (CO2–H2). All materials tested exhibit microporous character, enhancing adsorption of small molecules, however, it is the inclusion of a nitrogen-rich material into the gel matrix that results in enhanced selectivities for these systems. Despite the porous character of the gels, under the test conditions used to simulate industrial parameters, all three balance gases, i.e. H2, N2 and CH4, showed low affinities for the xerogels, while CO2 adsorption was notably higher and increased with the inclusion and increased concentration of melamine. Ideal adsorbed solution theory was used to demonstrate significant differences in adsorption uptake, especially for CO2–CH4, and high selectivities for CO2 over N2. In all cases, selected xerogels exhibited industrially relevant adsorption timescales for CO2 over competitor gases, demonstrating the potential of these materials for the selective adsorption of CO2 from process streams.

CuO grafted triazine functionalized covalent organic framework as an efficient catalyst for C-C homo coupling reaction

Designing of low cost catalytic system for new C-C bond formation reactions is very challenging in synthetic organic chemistry. Herein, we report a new copper oxide immobilized covalent organic framework (COF) material CuII-TRIPTA by grafting of CuO nanoparticles at the surface of a nitrogen rich porous COF material TRIPTA. TRIPTA has been synthesized through the extended Schiff base reaction between 2,4,6-triformylphloroglucinol and 1,3,5-tris-(4-aminophenyl) triazine. The COF as well as CuO loaded materials are characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG) and EPR spectroscopic analyses. CuII-TRIPTA material has been successfully applied as heterogeneous nanocatalyst for the C-C homo-coupling reaction of phenylboronic acids to synthesise wide range of biaryl compounds under mild and eco-friendly conditions (60 °C, methanol solvent). Remarkably high specific surface area of CuII-TRIPTA (583 m2 g−1) and highly accessible catalytic sites in the 2D-hexagonal COF nano-architecture potentially makes it excellent catalyst in the C-C bond formation reaction, which is evident from the high TON of the catalyst in this reaction. The catalyst was recollected and reused till 6th cycles without any noticeable change of its catalytic activity, suggesting its high catalytic efficiency in this C-C bond formation reaction.

Nanosecond-pulsed discharge in liquid nitrogen: optical characterization and production of an energetic non-molecular form of nitrogen-rich material

Nanosecond-pulsed discharge in liquid nitrogen ignited using a needle electrode and positive 60 kV high voltage pulses was characterized using fast and shadow imaging, as well as optical emission spectroscopy. Estimation of temperature was done using molecular nitrogen emission of second positive system ro-vibrational transition spectra, and the maximum temperature increase is estimated to be ~60 K. We also report on the first observations of plasma-generated unstable material from liquid nitrogen, presumably a form of polynitrogen compound.

Compost derived from local organic materials as source of plant nutrients

The aim of this study was to produce high quality compost and to interpret data during the composting process. Compost materials used in the composting were carbon-rich materials, nitrogen, and goat dung, added with topsoil from garden, rice husk, cow urine, and EM4 (microorganism effective 4). The method used was Indore method. The principle of this method is by placing every material in layers in a certain width, starting with carbon-rich material, nitrogen-rich material, goat dung, top soil, rice husk, and cow urine up to the surface of the compost bin. All the materials were watered until saturated condition. Incubation of compost took time 1.5 months. Data collected during the incubation process were temperature, moisture content, population of soil fungi and soilworms, compost texture, colour, pH, and nitrogen (N), phosphorus (P), potassium (K) contents. The results were as followed: temperature 37°C, moisture content 62%, population of fungus ++, population of soilworm +, the color black to brown, texture coarse to fine, no stingy smell, pH 7.0, and high N, P, K levels. The conclusions were that the compost was high in quality, all qualitative and quantitative data were correlated with the standards of a high quality compost.

Palladium-nitrogen coordinated cobalt alloy towards hydrogen oxidation and oxygen reduction reactions with high catalytic activity in renewable energy generations of proton exchange membrane fuel cell

Oxygen reduction reaction (ORR) is one of the most important processes in energy conversion and conservation in proton exchange membrane fuel cell (PEMFC). In PEMFC, developing non-platinum based catalyst by understanding the catalytic activity for both oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) is essential for energy storage/conversion. Herein, we report preparation of such a bi-functional and durable catalyst consists of palladium and nitrogen coordinated cobalt and its catalytic activity is discussed methodically. Palladium cobalt bimetallic alloy nanoparticles dispersed over graphitic carbon nitride (Pd-Co/gCN) serves as an efficient anode and cathode catalyst in proton exchange membrane fuel cell for energy conversion. Incorporation of cobalt with palladium in nitrogen rich support material optimally modifies the bond strength of palladium-hydrogen (Pd-H) complex and promotes HOR, results in significant improvement of overpotential at the anode whereas, the nitrogen coordinated cobalt predominantly enhances the ORR activity at the cathode in acidic medium. Effects of mass transfer on the kinetics of ORR were investigated with rotating disc electrode (RDE). The hydrodynamic voltammograms were investigated to determine the kinetic parameters using the Koutecky–Levich equation. Our study presents an experimental realization of unveiling a good power density with high fuel utilization efficiency in a single cell for electrochemical energy conversion with complete elimination of platinum.

2,4,6-tris[bis(1H-tetrazol-5-yl)amino]-1,3,5-triazine as a nitrogen-rich material

This paper describes the synthesis, characterization and energetic properties of tetrazole and triazine-based thermally stable, insensitive nitrogen-rich high energy density materials of N, N’, N”-(1,3,5-triazine-2,4,6-triyl) tris(N-cyanocyanamide) [1] and 2,4,6-tris[bis(1H-tetrazol-5-yl)amino]-1,3,5-triazine [2]. The compound 2 is the first example for compounds having six tetrazole units on a triazine ring. Synopsis Synthesis, characterization and energetic properties of the molecule, $$\hbox {N}_{2},\hbox {N}_{2},\hbox {N}_{4},\hbox {N}_{4},\hbox {N}_{6},\hbox {N}_{6}$$ -hexa(1H-tetrazol-5-yl)-1,3,5-triazine-2,4,6-triamine (2) having 79% nitrogen content with high HOF value is discussed. The high nitrogen content associated with high positive heat of formation of the compound 2 underline the structural importance of six tetrazole groups in a molecule.

Thermal behaviors of a novel nitrogen-rich energetic compound

A new nitrogen-rich energetic material, hydrazinium 3,5-dinitroamino-1,2,4-triazole (HDNAT), was synthesized. Thermal behavior and non-isothermal decomposition kinetics of HDNAT were studied with DSC and TG/DTG methods. The non-isothermal decomposition kinetic equation is $$\frac{{{\text{d}}\alpha }}{{{\text{d}}T}} = \frac{{10^{19.37} }}{\beta }6(1 - \alpha )^{{{2 \mathord{\left/ {\vphantom {2 3}} \right. \kern-0pt} 3}}} [1 - (1 - \alpha )^{{{1 \mathord{\left/ {\vphantom {1 3}} \right. \kern-0pt} 3}}} ]^{{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0pt} 2}}} \exp ( - 188.6 \times 10^{3} /RT)$$ . Self-accelerating decomposition temperature and critical temperature of thermal explosion of HDNAT are 168.1 and 178.1 °C, respectively. Specific heat capacity of HDNAT was determined with a micro-DSC method and the molar heat capacity is 258.96 J mol−1 K−1 at 298.15 K. Adiabatic time-to-explosion of HDNAT is about 100 s. The impact sensitivity, friction sensitivity, detonation velocity and detonation pressure of HDNAT are >13.1 J, 84 %, 9.0 km s–1 and 36.0 GPa, respectively.

Synthesis of Insensitive N-2,4-dinitrophenyl-N1-nitroguanidine

A new, insensitive nitroguanidyl functionalized nitrogen-rich material derived from 2,4-dinitrophenyl derivative was synthesized. N-2,4-dinitrophenyl-N1-nitroguanidine (DNP-NQ) has a crystal density of 1.74 g/cm3. The synthesis and properties of DNP-NQ are described. DNP-NQ was characterized by nuclear magnetic resonance (NMR), infrared spectroscopy, and gas pycnometry. Thermal properties were studied by differential scanning calorimetry (DSC). Results from small-scale sensitivity tests indicate that DNP-NQ is less sensitive than Cyclotrimethylenetrinitramine (RDX). DNP-NQ can be prepared in high yield.

Synthesis, characterization, and energetic properties of 6-amino-tetrazolo[1,5-b]-1,2,4,5-tetrazine-7-N-oxide: a nitrogen-rich material with high density.

The synthesis and energetic properties of a novel N-oxide high-nitrogen compound, 6-amino-tetrazolo[1,5-b]-1,2,4,5-tetrazine-7-N-oxide, are described. Resulting from the N-oxide and fused rings system, this molecule exhibits high density, excellent detonation properties, and acceptable impact and friction sensitivities, which suggests potential applications as an energetic material. Compared to known high-nitrogen compounds, such as 3,6-diazido-1,2,4,5-tetrazine (DiAT), 2,4,6-tri(azido)-1,3,5-triazine (TAT), and 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (TAAT), a marked performance and stability increase is seen. This supports the superior qualities of this new compound and the advantage of design strategy.