以硝酸铝和尿素为原料,通过水热法成功合成富含五配位Al^(3+)的γ-Al_(2)O_(3)载体,采用XRD、SEM、STEM-HAADF、27Al MAS NMR、N_(2)吸附-脱附等手段表征了载体的物理化学性质,并对采用该载体制备的Pd/Al_(2)O_(3)催化剂进行了蒽醌加氢...以硝酸铝和尿素为原料,通过水热法成功合成富含五配位Al^(3+)的γ-Al_(2)O_(3)载体,采用XRD、SEM、STEM-HAADF、27Al MAS NMR、N_(2)吸附-脱附等手段表征了载体的物理化学性质,并对采用该载体制备的Pd/Al_(2)O_(3)催化剂进行了蒽醌加氢制H_(2)O_(2)的初步性能评价。表征结果显示,合成的载体中的五配位Al^(3+)相对含量可达40.88%(w),微观粒子呈棒状,棒的长度1~4μm,直径0.1~0.3μm,BET比表面积可达494 m^(2)/g;所制备的Pd/Al_(2)O_(3)催化剂中Pd纳米粒子分散良好,平均粒径为3.51 nm,且分布较窄。评价结果表明,该催化剂相对于参比剂具有较高的加氢活性。展开更多
A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive material.The effects of Bi_(2)O_(3)in the PT...A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive material.The effects of Bi_(2)O_(3)in the PTFE/Al/Bi_(2)O_(3)on both mechanical properties and the energy release were investigated through various tests such as thermogravimetry-differential scanning calorimetry,adiabatic oxygen bomb test and split Hopkinson pressure bar test.The microstructure observed through scanning electron microscope and Xray diffraction results are used to analyze the ignition and reaction mechanism of PTFE/Al/Bi_(2)O_(3).The results indicate that the PTFE/Al/Bi_(2)O_(3)are capable of triggering the exothermic reaction of molten PTFE/Bi_(2)O_(3)and Al/Bi_(2)O_(3)over the PTFE/Al reactive materials,thereby promoting reactions.The excessive aluminum in the ternary system is beneficial for increasing energy release.The ignition of shock-induced chemical reactions in PTFE/Al/Bi_(2)O_(3)is closely related to the material fracture.The dominant mechanism for hot-spot generation under Split Hopkinson Pressure Bar test is the frictional temperature rise at the microcrack after failure.展开更多
文摘以硝酸铝和尿素为原料,通过水热法成功合成富含五配位Al^(3+)的γ-Al_(2)O_(3)载体,采用XRD、SEM、STEM-HAADF、27Al MAS NMR、N_(2)吸附-脱附等手段表征了载体的物理化学性质,并对采用该载体制备的Pd/Al_(2)O_(3)催化剂进行了蒽醌加氢制H_(2)O_(2)的初步性能评价。表征结果显示,合成的载体中的五配位Al^(3+)相对含量可达40.88%(w),微观粒子呈棒状,棒的长度1~4μm,直径0.1~0.3μm,BET比表面积可达494 m^(2)/g;所制备的Pd/Al_(2)O_(3)催化剂中Pd纳米粒子分散良好,平均粒径为3.51 nm,且分布较窄。评价结果表明,该催化剂相对于参比剂具有较高的加氢活性。
基金the National Natural Science Foundation of China (Grant No.12002045)State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology (Grant No.QNKT22-09)。
文摘A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive material.The effects of Bi_(2)O_(3)in the PTFE/Al/Bi_(2)O_(3)on both mechanical properties and the energy release were investigated through various tests such as thermogravimetry-differential scanning calorimetry,adiabatic oxygen bomb test and split Hopkinson pressure bar test.The microstructure observed through scanning electron microscope and Xray diffraction results are used to analyze the ignition and reaction mechanism of PTFE/Al/Bi_(2)O_(3).The results indicate that the PTFE/Al/Bi_(2)O_(3)are capable of triggering the exothermic reaction of molten PTFE/Bi_(2)O_(3)and Al/Bi_(2)O_(3)over the PTFE/Al reactive materials,thereby promoting reactions.The excessive aluminum in the ternary system is beneficial for increasing energy release.The ignition of shock-induced chemical reactions in PTFE/Al/Bi_(2)O_(3)is closely related to the material fracture.The dominant mechanism for hot-spot generation under Split Hopkinson Pressure Bar test is the frictional temperature rise at the microcrack after failure.
