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In order to promote the development of molecular perovskite energetic materials, studying thermal decomposition performances of AP-based molecular perovskite energetic materials ((H2dabco)[NH4(ClO4)3], DAP-4) catalyzed by metal hydrogen storage fuel is significant. In this study, the morphology, structure and thermal decomposition characteristics of TiH2, DAP-4 and DAP-4/TiH2 composite materials were characterized and investigated. The experimental results showed that the DAP-4 peak exothermic temperature at different heating rates both showed a decreasing trend with TiH2 content increased. With 20 wt% TiH2 added, the DAP-4 peak exothermic temperature decreased from 394.3 ℃ to 352.8 ℃ (10 ℃/min heating rate), and the apparent activation energy (Ea) also decreased from 201.5 KJ/mol to 182.3 KJ/mol. A possible catalytic thermal decomposition mechanism of perovskite catalyzed by TiH2 was proposed. This work is helpful to further understand the thermal decomposition characteristics of molecular perovskite energetic materials in the presence of metal hydrides. [ABSTRACT FROM AUTHOR]

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Nano (H2dabco)[K(ClO4)3 (DAP-2) were successfully prepared via the milling method. The morphology and structure of the as-obtained sample were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The results showed the nano DAP-2 with nearly spherical morphologies have a narrow particle size distribution ranged from 1μm to 2μm. The thermal decomposition properties were investigated by thermogravimetric-differential scanning calorimeter (TG-DSC). The exothermal peak of nano DAP-2 thermal decomposition is 384.5°C decreased by 6.7°C compared with raw DAP-2 (391.2°C). And the apparent activation energy (Ea) of nano DAP-2 was calculated as 173.346 kJ mol−1 by Kissinger equation, which is lower than raw DAP-2 (177.699 kJ·mol−1). Sensitivity study showed that the nano DAP-2 (H50: 60.63 cm) exhibited lower impact sensitivity than raw DAP-2 (H50: 36.79 cm). Therefore, this work provides a simple and effective way to improve the thermal decomposition properties and safety performance of molecular perovskite energetic materials. [ABSTRACT FROM AUTHOR]

Metal hydride has been used as a potential energetic material due to its high hydrogen storage density, high reactivity, high mass calorific value and large gas production. But it was still a great challenge towards optimizing and enhancing the energy-releasing properties of metal hydride. In this work, a novel molecular perovskite energetic material (H 2 dabco)[NH 4 (ClO 4) 3 ] (DAP-4) was introduced as a high energy oxidant to fabricate metal hydride (MH 2 , M=Mg, Ti, and Zr) based energetic composites. The thermal decomposition, ignition and combustion characteristics of MH 2 -based energetic composites were studied. The results showed that molecular perovskite energetic material DAP-4 was beneficial as oxidant in MH 2 -based high-energy solid composites, which were originated from its high energy properties and strong oxidation capacity. The ignition and combustion reaction mechanisms of MH 2 with DAP-4 as oxidant were provided. This work offered an effective way to realize energy-releasing performance of MH 2 by molecular perovskite energetic materials introduced for their potential application. [ABSTRACT FROM AUTHOR]

The development of novel catalysts with high-activity to improve the thermal-induced pyrolysis of energetic molecular perovskite is of great importance. In this work, flower-like MnO 2 nanostructure was fabricated by a facile hydrothermal method with KMnO 4 as only precursor, and its thermal-induced pyrolysis performance of energetic molecular perovskite DAP-4 was studied. Results showed the catalysis thermal-induced pyrolysis peak temperature of DAP-4 had reduced by 50 °C from 386 °C (raw DAP-4) to 336 °C (DAP-4/10 wt% MnO 2) by the flower-like MnO 2 nanostructure, with rich oxygen vacancy added. The heat release of DAP-4 thermal-induced pyrolysis processes had a trend of increasing from 3423 J/g to 3563 J/g first and then decreasing to 2223 J/g. The apparent activation energy of DAP-4 had been reduced to 144 kJ/mol with addition of 10 wt% MnO 2. The catalysis mechanism of MnO 2 with flower-like nanostructure on thermal-induced pyrolysis of DAP-4 was provided. • Flower-like MnO 2 nanostructure with rich oxygen vacancy was fabricated by a facile hydrothermal method. • Lower catalytic thermal-induced pyrolysis temperature and higher heat release, and lower activation energy were obtained. • The catalysis mechanism of MnO 2 with flower-like nanostructure on thermal-induced pyrolysis of DAP-4 was provided. [ABSTRACT FROM AUTHOR]

Nonmetal fuel boron (B) had received much attention in the advanced solid propellants. However, the efficient ignition and combustion of B particles still held a huge challenge. In this work, as a typical molecular perovskite energetic material, (H 2 dabco)[NH 4 (ClO 4) 3 ] (DAP-4) was introduced as oxidant to design and prepare B-based fuel-oxidant materials, and the ignition and combustion behavior of boron particles by using DAP-4 as high-energy oxidant were studied. The results suggested DAP-4 with high energy property and strong oxidation ability has great potential as high-energy oxidant to be used in B-rich solid propellant systems. By adjusting the B/O ratios of DAP-4/B, the energy-releasing reaction properties of B particles were studied during the thermal decomposition, ignition, and combustion processes. The ignition and combustion reaction mechanism of B with DAP-4 as high-energy oxidant was discussed. Therefore, this work provides a proof-of-principle concept for the design and fabrication of molecular perovskite energetic materials-based B-rich high-energy solid propellants. [ABSTRACT FROM AUTHOR]

Development of novel high-energy and strong-oxidization oxidizer towards tailoring the energy releasing performance of solid fuel is still a great challenge. In this work, energetic molecular perovskite (H 2 dabco)[NH 4 (ClO 4) 3 ] (DAP-4) was considered as a novel oxidizer to tailor energy releasing performance of solid fuel magnesium (Mg), aluminum (Al), and silicon (Si). The solid fuel-based composite with DAP-4 as oxidizer were characterized by the excellent energy releasing properties. The combustion heat value of Mg/DAP-4, Al/DAP-4 and Si/DAP-4 was 11020 J/g, 10410 J/g and 9330 J/g, respectively. Their flame spread rates of mixtures were 31.7, 98.0, and 14.4 mm/s, respectively, and the solid fuel-based composite with F 2602 as binder also showed associated burning rates. The flame spread rates of Mg/DAP-4/F, Al/DAP-4/F, and Si/DAP-4/F composites were 12.50, 18.56, and 6.38 mm/s, respectively. The ignition and combustion energy releasing reaction mechanism of solid fuel-based composite with DAP-4 as oxidizer was proposed. This work offered a proof of concept that energetic molecular perovskite had great potential as oxidizer towards the utilization for solid propellant. • The solid fuel-based composite with DAP-4 as oxidizer were characterized by the excellent energy releasing properties. • DAP-4 can release a lot of energy and oxidizing gases, which will ignite the solid fuel and support continuous reaction. • The energy releasing reaction mechanism of solid fuel-based composite with DAP-4 as oxidizer was proposed. [ABSTRACT FROM AUTHOR]

In this work, the catalytic combustion performance of molecular perovskite energetic material DAP-4 with assembled Cu 2 O nanoclusters added was studied. Results showed that aggregated spherical Cu 2 O clusters with the size of ∼1 μm were assembled by nano particles with ∼50 nm diameter by the high-temperature reduction method. Assembled Cu 2 O nanoclusters have intrinsic catalysis combustion characteristics on DAP-4. With 5 wt% Cu 2 O added, the combustion time of DAP-4 had reduced by ∼70 ms from raw DAP-4 (∼90 ms) to DAP-4/Cu 2 O (20 ms). The combustion pressurization rate of DAP-4/Cu 2 O is ∼4 times of DAP-4. The catalysis combustion mechanism of DAP-4 with assembled Cu 2 O nanoclusters as an additive was proposed. The work offered a new idea to utilize novel catalysts for enhancing the combustion performance of DAP-4. • Assembled Cu 2 O nanoclusters were prepared by a high-temperature reduction method. • Cu 2 O has intrinsic catalysis combustion characteristic on DAP-4. • The combustion pressurization rate of DAP-4/Cu 2 O is ∼4 times of DAP-4. • The catalysis combustion mechanism of DAP-4/Cu 2 O was proposed. [ABSTRACT FROM AUTHOR]

In this study, we reported that two-dimensional titanium carbide (Ti 3 C 2) MXene has intrinsic catalytic activity for thermal decomposition of high-energy ammonium perchlorate-based molecule perovskite (H 2 dabco)[NH 4 (ClO 4) 3 ] (DAP-4). The micro morphology and structure of Ti 3 C 2 MXene were characterized. Thermal catalysis decomposition of DAP-4 using Ti 3 C 2 as a novel catalyst was investigated by Differential scanning calorimetry (DSC). The results showed that with 10 wt% Ti 3 C 2 added, the decomposition temperature of DAP-4 was reduced to 341.2 °C at the heating rate of 10 °C·min−1, which decreased by 43.8 °C from raw DAP-4 (385 °C). The activation energy of DAP-4 thermal decomposition effectively reduced from 181 kJ mol−1 to 155 kJ mol−1. A possible mechanism of Ti 3 C 2 MXene for the catalysis thermal decomposition of DAP-4 was proposed. This work provides a proof-of-principle concept for the thermal catalysis decomposition of ammonium perchlorate-based molecule perovskite energetic materials using the titanium carbide MXene as a catalyst. • Ti 3 C 2 MXene has intrinsic catalytic activity for thermal decomposition of DAP-4. • The decomposition temperature and activation energy of DAP-4 has reduced to 341.2 °C and 155 kJ mol−1. • A possible mechanism of Ti 3 C 2 MXene for the catalysis thermal decomposition of DAP-4 was proposed. [ABSTRACT FROM AUTHOR]

Molecular perovskite energetic material DAP-4 is seen as a potential high-energy oxidant due to its high energy, high density, high oxidation capacity, and facile preparation technology. However, optimizing its energy release and reducing its thermal decomposition temperature are huge challenges for its future application. In this work, the role of iron (Fe) nanospheres in the energy release of DAP-4 was studied. Our research has shown that Fe powder can not only serve as a fuel to promote combustion, but also as an important catalyst to significantly improve the thermal decomposition, energy release, and burning rate of DAP-4. By adding 25% Fe nanospheres, the decomposition temperature of DAP-4 was reduced to 299.7 °C, which is the most reduction by 84.7 °C from 384.4 °C (raw DAP-4) to 299.7 °C (DAP-4/Fe-5 with 25wt% Fe nanospheres) was obtained. The decomposition activation energy also decreases by at least 69.5 kJ mol−1 from 229.4 kJ mol−1 (DAP-4) to 159.9 kJ mol−1 (DAP-4/Fe-1 with 5wt% Fe nanospheres). The combustion performance of DAP-4/Fe composites is significantly improved by a 4∼5 times shorter burn rate. The energy-releasing mechanism of DAP-4 with the presence of Fe nanospheres was proposed. Fe x O y at the surface of Fe nanospheres played an important role in the energy releasing of DAP-4. This work showed a new idea for the potential application of molecular perovskite energetic materials. [ABSTRACT FROM AUTHOR]

Nano Silicon (Si) powder has become a new type of solid fuel in recent years because of its high energy density, large gas production, and low agglomeration behavior. Optimizing and improving its energy release performance is an important challenge. In this paper, DAP-4, an energetic molecular perovskite material with high energy and strong oxidation, was introduced as the oxidant to prepare DAP-4/Si composites, and its combustion properties were studied. The thermal decomposition, combustion performance, as well as their combustion product properties, were studied. The results showed the thermal decomposition properties of DAP-4/Si composites still keep stable (>370 °C), and the combustion properties of DAP-4/Si composites first increase with Si content and then reduced. It was confirmed that DAP-4/Si with the ratio of 6.5:3.5–6:4 had a better burning intensity than the other ratios. The combustion mechanism of DAP-4/Si composites was proposed based on the ignition and combustion characteristics of DAP-4/Si composites. This work may provide a further reference for the application of DAP-4 into solid propellant formulation. • (H 2 dabco)[NH 4 (ClO 4) 3 ] DAP-4/Si composites were prepared and characterized. • The combustion properties of DAP-4/Si composites were researched. • DAP-4/Si with the ratio of 6.5:3.5–6:4 had a better burning intensity than the other ratios. • The combustion mechanism of DAP-4/Si composites was proposed. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the effect of Iron carbide-nitride/reduced graphene oxide composites (FeC x N y /rGO) as catalysts on the thermal decomposition of energetic molecular perovskite (H 2 dabco)[M(ClO 4) 3 ] (DAPs, M = Na+, K+ and NH 4 + for DAP-1, -2, and -4). FeC x N y /rGO were fabricated by two-step method combined with chemical synthesis and sinter technology of Prussian blue/reduced graphene oxide (PB/rGO). The morphology and structure of FeC x N y /rGO were characterized. The thermal decomposition performance of DAPs with FeC x N y /rGO catalyzed were studied. Results showed that FeC x N y particles with mainly Fe–C and Fe–N bonds involved were located at the surface of rGO nanosheets, the peak thermal decomposition temperature and the apparent activation energy of DAPs were both significantly decreased in the presence of FeC x N y /rGO. Among them, with 5 wt% FeC x N y /rGO-2 added, the peak temperature of DAP-1, DAP-2, and DAP-4 have been decreased by 104.8 °C, 110 °C and 102.2 °C, respectively. Their apparent activation energy decreased significantly by 4.0 kJ/mol, 74.9 kJ/mol and 66.9 kJ/mol, respectively. A possibly thermal catalysis decomposition mechanism was provided. This work provides a new idea for design and fabrication of multifunctional catalysts to enhance the thermal decomposition of energetic molecular perovskite and offers the possibility of applying DAPs to rocket solid propellant. [Display omitted] • FeCxNy/rGO is designed and synthesized. • FeCxNy/rGO is used for the thermal decomposition of energetic molecular perovskite (H 2 dabco)[M(ClO 4) 3 ] (M = Na+, K+ and NH 4 +). • FeCxNy/rGO shows excellent catalytic performance. [ABSTRACT FROM AUTHOR]

The application of nano-catalytic materials in molecular perovskite energetic materials is of great significance to promote the development of molecular perovskite energetic materials in explosive formulations and propellants. In this paper, the thermal catalytic effects of CoFe-layered double hydroxide derivative on the molecular perovskite energetic material (DAP-4) were studied. In this study, we successfully prepared a new type of CoFe-based photothermal agent (CoFe-500) by heating CoFe layered double hydroxide nanosheets in an Ar atmosphere at 500 °C. And the micromorphology, structure composition, thermal decomposition performances of CoFe-500 and DAP-4/CoFe-500 composite were characterized. The experimental results showed that with the addition of CoFe-500, the initial decomposition temperature and peak exothermic temperature of DAP-4 showed a decreasing trend. With 10 wt% CoFe-500 added, the initial decomposition temperature and peak exothermic temperature of DAP-4 decreased from 305.6 °C to 166.3 °C and 379.0 °C–322.5 °C, respectively (10 °C/min heating rate). The apparent activation energy (E a) of pure DAP-4 is 172.27 kJ/mol and 175.13 kJ/mol calculated by the Kissinger and Ozawa method, respectively. And with 10 wt% CoFe-500 added, the E a is reduced to 119.11 kJ/mol and 122.84 kJ/mol, respectively. The possible thermal catalytic decomposition mechanism of DAP-4/CoFe-500 composites was proposed from the thermal analysis and mass spectrometry test results. This work is meaningful to further understand the decomposition performances of DAP-4 in the presence of nano-layered double hydroxide. • The thermal catalytic effects of CoFe-layered double hydroxide derivative on the DAP-4 were studied for the first time. • The initial decomposition temperature and T p of DAP-4 showed a decreasing trend with the increase of CoFe-500 content. • A possible thermal decomposition mechanism of DAP-4 catalyzed by CoFe-500 was proposed. [ABSTRACT FROM AUTHOR]

In this paper, we studied the effect of M-doped graphitic carbon nitride (M-g-C 3 N 4 , M = Fe, Nd, Ce, Zr, U) as a catalyst for the thermal decomposition of ammonium perchlorate-based molecular perovskite DAP-4. DAP-4 was synthesized by a molecular assembly strategy. G-C 3 N 4 and M-g-C 3 N 4 composite samples were prepared by pyrolytic and co-sintering methods. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy-energy dispersion X-ray spectrometry, and X-ray photoelectron spectroscopy were used to characterize the morphology, structure, element distribution, and element chemical states of the catalysts. Differential scanning calorimetry was used to elevate the thermal catalytic decomposition effect of g-C 3 N 4 and M-g-C 3 N 4 on DAP-4. The results showed that g-C 3 N 4 and M-g-C 3 N 4 have catalytic activity for the thermal decomposition of DAP-4. Among the tested catalysts, Fe-g-C 3 N 4 had the best catalytic activity for the thermal decomposition of DAP-4, as well as advantages over pure g-C 3 N 4 and other M-g-C 3 N 4 catalysts. Especially, Fe-g-C 3 N 4 reduced the peak temperature of DAP-4 by 75.3 °C, increased heat release by 464 J g−1, and decreased activation energy by 55.5 kJ mol−1. Moreover, a possible catalytic mechanism is proposed. This work may offer a new way to promote the application of DAP-4 in the field of solid rocket propellants. Unlabelled Image • Metal-doped g-C 3 N 4 is designed and synthesized. • Metal-doped g-C 3 N 4 is used for the thermal decomposition of (H 2 dabco)[NH 4 (ClO 4) 3. • Fe-g-C 3 N 4 shows excellent catalytic performance. [ABSTRACT FROM AUTHOR]