CAJ | 학술논문

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/SiO_2).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/SiO_2保持了磷钼酸铵(AMPA)杂多酸盐的Keggin结构.AMPA以及AMPA/SiO_2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.
이정규산을지위규원,이용용효-응효법제비부재린목잡다산안최화제(AMPA/SiO_2).채용X사선연사화홍외광보측시기술대최화제진행료표정,병초보평개료최화제분초화반응최화성능.결과표명,용효-응효법제비적AMPA/SiO_2보지료린목산안(AMPA)잡다산염적Keggin결구.AMPA이급AMPA/SiO_2최화제균표현출교강적분초화반응최화활성화100%적일초기분선택성,분최고전화솔위96%.반응후부재최화제활성조분유소손실,단최화제정체물상화결구몰유발생명현변화.
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.