六铝酸盐LaMnAl_(11)O_(19-α)催化合成甲基二氯化膦

Synthesis of Methyl Phosphonic Dichloride on Hexaaluminate LaMnAl_(11)O_(19-α)Catalyst

采用共沉淀法制备了六铝酸盐 LaMnAl_(11)O_(19-α);以 LaMnAl_(11)O_(19-α)为催化剂、CH_4和 PCl_3为原料,合成甲基二氯化膦。考察了 n(CH_4):n(PCl_3)、催化剂粒径、反应温度对合成反应的影响,确定了较适宜的反应条件,并考察了催化剂的稳定性。实验结果表明,合成甲基二氯化膦的适宜反应条件为:以焙烧温度为1 200℃的 LaMnAl_(11)O_(19-α)为催化剂,n(CH_4):n(PCl_3)=10:1,催化剂粒径425～850μm,反应温度300℃。在此条件下,PCl_3的转化率为6.84%。使用LaMnAl_(11)O_(19-α)催化剂可降低反应温度,反应中不需通入氧气作为辅助催化剂,解决了高温通氧气易爆炸的问题,同时降低了生产成本,但LaMnAl_(11)O_(19-α)催化剂的稳定性较差,使用寿命短。

Hexaaluminate LaMnAl11O19-α was prepared by co-precipitation. Methyl phosphonic dichloride was synthesized from methane and phosphorus trichloride LaMnAl11O19-α as catalyst. Effects of n （CH4 ） ： n （PCl3 ） , particle size of catalyst and reaction temperature on conversion of phosphorus trichloride were studied. Catalyst stability was noticed. Under optimal conditions： LaMnAl11O19-α as catalyst calcined at 1 200 ℃, catalyst particle size 425 - 850 μm, n （ CH4 ） ： n （ PCl3 ） = 10 ： 1 and reaction temperature 300 ℃, conversion of phosphorus trichloride is 6.84%. When LaMnAl11O19-α catalyst is used, reaction temperature can be greatly reduced, and oxygen as cocatalyst is no more necessary. Therefore the possible explosion and formation of phosphorus oxychloride as undesirable byproduct can be avoided. But the stability of LaMnAl11O19-α catalyst is not good enough to be accepted.