The technique to prepare TiH\-2 coated with layers of Al\-2O\-3 particles by heterogeneous nucleation method with HAc\|NaAc buffer solution as precipitation reagent was studied. The results show that the microscopic s...The technique to prepare TiH\-2 coated with layers of Al\-2O\-3 particles by heterogeneous nucleation method with HAc\|NaAc buffer solution as precipitation reagent was studied. The results show that the microscopic structure of Al\-2O\-3 coating layers depends on the pH value and Al\+\{3+\} concentration range in the solution. The homogeneous and compact coating layers with Al\-2O\-3\|coated TiH\-2 particles can be obtained at 0.05 mol/L and pH=4.5, after heating at 350 ℃. The hydrogen releasing of Al\-2O\-3/TiH\-2 particle is notably delayed with the increase of the temperature, and the delay effect can be used in the production of Al foams.展开更多
The coating process of TiH2 particles with SiO2 layers, and the effect of the coating layer on hydrogen release characteristic of TiH2 powders were studied experimentally. The gelation rate of silicic acid is an impor...The coating process of TiH2 particles with SiO2 layers, and the effect of the coating layer on hydrogen release characteristic of TiH2 powders were studied experimentally. The gelation rate of silicic acid is an important factor for controlling the surface morphologies of coating layers. When the concentration of SiO2-3 is about 0.5 mol/L, the condensation rate of silicic acid is appropriate for the formation of a homogeneous and dense coating membrane. The results of hydrogen release at 700 ℃ show that TiH2 particles coated with silicon dioxide layers can efficiently delay the starting time of hydrogen release of TiH2 powders to 60100 s.展开更多
采用简单液体浸渍还原法合成出Ru@UIO-66、Co P@UIO-66、Ru P@UIO-66和Ru Co P@UIO-66催化剂.利用XRD、TEM、ICP-AES、BET和XPS等物理手段对其结构、形貌、尺寸、组成、比表面及金属价态等进行表征.催化活性实验通过催化氨硼烷水解释氢...采用简单液体浸渍还原法合成出Ru@UIO-66、Co P@UIO-66、Ru P@UIO-66和Ru Co P@UIO-66催化剂.利用XRD、TEM、ICP-AES、BET和XPS等物理手段对其结构、形貌、尺寸、组成、比表面及金属价态等进行表征.催化活性实验通过催化氨硼烷水解释氢速率进行检测.结果表明,非金属磷的加入显著提高了催化活性,其中三组分Ru Co P@UIO-66催化活性最高,其反应的转换频率(TOF)和活化能(Ea)分别为105.36 mol H2min-1(mol Ru)-1和44.5 k J mol-1.这种高的催化活性主要归因于UIO-66的高比表面积和多孔结构使负载粒子均匀分散,同时P的加入减小了Ru和Co纳米粒子的粒径,也增强了Ru-Co-P之间的电子效应.此外,Ru Co P@UIO-66催化剂经过5次循环后,仍然保留初始催化活性的55.6%,有较好的循环稳定性.展开更多
文摘The technique to prepare TiH\-2 coated with layers of Al\-2O\-3 particles by heterogeneous nucleation method with HAc\|NaAc buffer solution as precipitation reagent was studied. The results show that the microscopic structure of Al\-2O\-3 coating layers depends on the pH value and Al\+\{3+\} concentration range in the solution. The homogeneous and compact coating layers with Al\-2O\-3\|coated TiH\-2 particles can be obtained at 0.05 mol/L and pH=4.5, after heating at 350 ℃. The hydrogen releasing of Al\-2O\-3/TiH\-2 particle is notably delayed with the increase of the temperature, and the delay effect can be used in the production of Al foams.
文摘The coating process of TiH2 particles with SiO2 layers, and the effect of the coating layer on hydrogen release characteristic of TiH2 powders were studied experimentally. The gelation rate of silicic acid is an important factor for controlling the surface morphologies of coating layers. When the concentration of SiO2-3 is about 0.5 mol/L, the condensation rate of silicic acid is appropriate for the formation of a homogeneous and dense coating membrane. The results of hydrogen release at 700 ℃ show that TiH2 particles coated with silicon dioxide layers can efficiently delay the starting time of hydrogen release of TiH2 powders to 60100 s.
文摘采用简单液体浸渍还原法合成出Ru@UIO-66、Co P@UIO-66、Ru P@UIO-66和Ru Co P@UIO-66催化剂.利用XRD、TEM、ICP-AES、BET和XPS等物理手段对其结构、形貌、尺寸、组成、比表面及金属价态等进行表征.催化活性实验通过催化氨硼烷水解释氢速率进行检测.结果表明,非金属磷的加入显著提高了催化活性,其中三组分Ru Co P@UIO-66催化活性最高,其反应的转换频率(TOF)和活化能(Ea)分别为105.36 mol H2min-1(mol Ru)-1和44.5 k J mol-1.这种高的催化活性主要归因于UIO-66的高比表面积和多孔结构使负载粒子均匀分散,同时P的加入减小了Ru和Co纳米粒子的粒径,也增强了Ru-Co-P之间的电子效应.此外,Ru Co P@UIO-66催化剂经过5次循环后,仍然保留初始催化活性的55.6%,有较好的循环稳定性.
