论文部分内容阅读
采用溶胶凝胶法、共沸蒸馏法和水热合成法制备了Al_2O_3掺杂W粉末,并经煅烧以及两段氢气还原过程制成W-Al_2O_3复合粉末。通过SEM形貌观察以及XRD物相分析可知,由3种方法制备的Al_2O_3掺杂W粉末经过煅烧均得到了稳态单斜相WO_3和非稳态六方相WO_3;其中水热合成法制得粉末形貌较为规则,为均匀的小球状;经过一段氢气还原,WO_3被还原为低价态的WO_2和不饱和价态的WO_3-x;二段氢气还原后得到了细小的W-Al_2O_3复合粉末。采用溶胶凝胶法制备的W-Al_2O_3复合粉末,由于Al_2O_3包裹在W颗粒表面阻碍了后续被还原W原子的沉积,相较于其他两种方法细化作用更加明显,颗粒可达纳米级。
Al 2 O 3 -doped W powder was prepared by sol-gel method, azeotropic distillation and hydrothermal synthesis. The W-Al 2 O 3 composite powder was prepared by calcination and hydrogen reduction. SEM observation and XRD phase analysis showed that the powders of Al 2 O 3 doped W prepared by the three methods were calcined to obtain the monoclinic phase WO 3 and the non-steady phase WO 3. The hydrothermal synthesis method was used to prepare powder After a period of hydrogen reduction, WO_3 was reduced to the low-valent WO_2 and the unsaturated valence WO_3-x. The second-stage hydrogen reduced the fine W-Al_2O_3 composite powder. The W-Al_2O_3 composite powders prepared by sol-gel method have the effect of thinning W atoms, which is more obvious than the other two methods due to the inclusion of Al_2O_3 on the surface of W particles.