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(H_(2)AzTO),as a high-energy nitrogen-rich material,was selected as a ligand.Five kinds of La^(3+),Ce^(3+),Pr^(3+),Nd^(3+),and Sm^(3+)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 compa red with that of the ligand.The results of thermicdecomposition of ammonium perchlorate(AP)and AP mixtures with 10 wt%EMOFs 1-5 show that except for AP mixed with 10 wt%co mpound 2,the high-temperature decomposition peak tempe rature 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 thermicdecomposition of AP.

Catalytic Kinetic on the Thermal Decomposition of Ammonium Perchlorate with a New Energetic Complex Based on 3,5-Bis(3-pyridyl)-1H-1,2,4-triazole

A new energetic complex,[Co（3,3？-Hbpt）（Htm）]·H_2O（1,3,3？-Hbpt = 3,5-bis（3-pyridyl）-1H-1,2,4-triazole and H_3tm = trimesic acid）,has been synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction,elementary analysis,IR spectroscopy,thermogravimetric analysis and X-ray powder diffraction. Single-crystal X-ray diffraction indicates that the complex belongs to triclinic system,space group P 1 with a = 10.0911（1）,b = 10.2573（1）,c = 10.6393（1） ？,α = 103.793（2）,β = 101.041（2）,γ = 107.918（3）o,V = 974.9（2） ？~3,Z = 2,D_c = 1.732 g·cm-3,μ = 0.941 mm^（-1）,M_r = 508.31,F（000） = 518,the final R = 0.0523 and wR = 0.0935 with I 〉 2σ（I）. In the title complex,Co（Ⅱ） ions are connected by Htm2-anions generating 1D ladder-like chains which are linked by 3,3？-Hbpt to form 1D cages. In addition,the thermal decomposition of ammonium perchlorate（AP） with complex 1 was explored by differential scanning calorimetry（DSC）. AP is completely decomposed in a shorter time in the presence of complex 1,and the decomposition heat of the mixture is 2.531 kJ·g^（-1）,significantly higher than that of pure AP. By Kissinger＇s method,the ratio of Ea/ln（A） is 11.05 for the mixture,which indicates that complex 1 shows good catalytic activity toward the AP decomposition.

Electro-catalytic degradation properties of Ti/SnO_2–Sb electrodes doped with different rare earths

Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of the electrode can be significantly improved by doping rare earth（RE） ions into the oxide coating of Ti/SnO2–Sb electrode. Ti/SnO2–Sb electrodes doped with different RE elements（Ce, Dy, La, and Eu） were prepared by the thermal decomposition method at 550 ℃. Electro-catalytic degradation performances of electrodes doped with different RE elements were evaluated by linear sweep voltammetry（LSV） and Tafel curves. During the electrolysis,the conversion of p-nitrophenol was performed with these electrodes as anodes under galvanostatic control. The structures and morphologies of the surface coating of the electrodes were characterized by scanning electron microscope（SEM）. The results demonstrate that the electro-catalytic degradation performances of Ti/SnO2–Sb electrodes are improved to different levels by doping different RE ions. Improved Ti/SnO2–Sb electrodes by the introduction of different RE have higher oxygen evolution potential, better electro-catalysis ability, better coverage,and longer electrode life.