溶胶-凝胶法制备负载磷钼杂多酸铵催化苯硝化反应

以正硅酸乙酯为硅源，利用溶胶-凝胶法制备负载磷钼杂多酸铵催化剂（AMPA/SiO2），采用X射线衍射和红外光谱测试技术对催化剂进行了表征，并初步评价了催化剂苯硝化反应催化性能。结果表明，溶胶-凝胶法制备的AMPA/SiO2保持了磷钼酸铵（AMPA）杂多酸盐的Keggin结构。AMPA以及AMPA/SiO2催化剂均表现出较强的苯硝化反应催化活性和100 ％的一硝基苯选择性，苯最高转化率为96 ％。反应后负载催化剂活性组分有所损失，但催化剂整体物相和结构没有发生明显变化。

Nitration of Benzene Catalyzed by Supported Ammonium Molybdophosphat Catalyst

A series of supported ammonium molybdophosphat catalysts(AMPA/SiO_2) with different loading was prepared from tetraethyl orthosilicate, ammonium molybdate and ammonium dihydrogen phosphate by sol-gel method. The samples were characterized by X-ray diffraction(XRD) and IR spectrometry. The catalytic activities of these catalysts were evaluated for the liquid phase nitration of benzene in 65% nitric acid without solvent at 70 ℃. Results indicate that supported catalyst still maintained the Keggin structure of ammonium molybdophosphate catalyst and exhibited high nitration reaction catalytic activity and high selectivity of mononitrobenzene. Among these catalysts, the catalyst with 10% loading showed maximum activity(96%), with 100% selectivity towards mononitrobenzene. The reusability of the catalysts was also studied, and it was found that there was no obvious change for catalyst phase and structure after being reused four times, although the active component had somewhat been lost in the reaction process.