摘 要: | 制备了Cs_(0.5)H_(2.5)PW_(12)O_(40)、Cs_(1.5)H-_(1.5)PW_(12)O_(40)、Cs_(2.5)H_(0.5)PW_(12)O_(40)、Zn_(1.5)PW_(12)O_(40)、Ag_3PW_(12)O_(40)、Al PW_(12)O_(40)、Sn_(0.5)H_2PW_(12)O_(40)、SnHPW_(12)O_(40)、Sn_(1.5)PW_(12)O_(40)等九种12-磷钨酸盐,通过IR、XRD和UV进行了表征,结果表明九种磷钨酸盐均具有Keggin结构。以环己酮为原料,30%H_2O_2为氧化剂,九种磷钨酸盐对己二酸的催化合成都有催化活性,其中SnHPW_(12)O_(40)和Ag_3PW_(12)O_(40)的催化活性更佳。实验条件为0.8 g SnHPW_(12)O_(40),30% H_2O_2 45 mL,无酸性配体,回流反应6 h,己二酸收率71.23%;Ag_3PW_(12)O_(40)为0.8 g,30%H_2O_2 50 mL,无酸性配体,回流反应5 h,己二酸收率达74.45%。此外SnHPW_(12)O_(40)和Ag_3PW_(12)O_(40)还具有良好的重复使用性,使用6次己二酸收率分别为58.22%和62.74%。
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