以纳米碳纤维/碳毡(CFF)为载体,分别采用碳热氢气还原法和碳热氨气还原法制备了负载型碳化钨、碳氮化钨整体催化剂,XRD结果表明催化剂的活性相分别为W2C和WCxNy, TEM表征发现其粒子尺寸分别为2~40 nm和2~20 nm。采用1 N肼分解推力器评价了上述催化剂的反应性能,W2C/CFF和WCxNy/CFF表现出了相比于Ir/CFF更好的肼分解综合性能:除了初活性略低以外,启动加速性、稳态燃压以及比活性均高于贵金属Ir催化剂。此外,W2C/CFF和WCxNy/CFF催化剂的稳定性明显优于Ir/CFF,这主要是由于CFF载体在贵金属Ir的作用下发生了更显著的甲烷化反应。
Cabon fiber felt (CFF) supported tungsten carbide and tungsten carbonitride were prepared using a carbonthermal hydrogen reduction process and a carbonthermal ammonia reduction process, respectively. The XRD and TEM results indicated the formation of W2C and WCxNy phase on the above samples with the corresponding particle size range of 2—40 nm and 2—20 nm, respectively. It was found that both catalysts exhibited desired catalytic performances in a one Newton hydrazine microthruster. The properties, including the ignition delay, the steady chamber pressure as well as the steady catalyst bed temperature over the W2C/CFF and WCxNy/CFF catalysts, were better than those over the Ir/CFF. Moreover, due to the negligible activity in methanation reaction, the tungsten-based catalysts exhibited a higher stability than the Ir/CFF catalysts.