【摘要】 以偏钨酸铵为钨源,CO为还原性气体和碳源,采用喷雾干燥微球化处理—气固反应法制备了具有介孔结构空心球状的WC粉体.采用XRD,SEM,EDS和TG-DTA等分析手段对样品的形貌、物相组成、化学成分以及在空气中的热稳定性进行了表征.结果表明,碳化钨粉体为缺碳含氧的WC相,化学成分为W,C,O,W与C的原子比接近1∶1;碳化钨颗粒为分散性良好的空心球状,表面具有介孔结构;TG-DTA曲线表明,样品在空气中具有良好的热稳定性.更多还原

【Abstract】 Hollow global tungsten carbide (WC) catalysts with meso-porosity were prepared by spray dry- ing sphere miniaturation—gas-solid reaction, using ammonium metatungstate as precursors, carbon monox- ide as deoxidizing gas and carbon dioxide as carrier gas. The samples were characterized by XRD, SEM, EDS and TG-DTA, respectively. XRD and EDS results show that the sample took pure WC phase, with a ra- tio of W/C near 1. TG-DTA results show that the sample is stable in the air under 400 ℃. SEM images in- dicate that the morphology of the sample is hollow globe with meso-porosity on the surface. The hollow globe was constituted by a lot of puncheons, with a length of 100～800 nm and a width of 50～150 nm. The joint between two puncheons lies on tips or tip and the surface of puncheon. Puncheons were surrounded by cavities. The cavity connects with each other, with different shapes and a size of 0～200 nm.更多还原