CAJ | 학술논문

以硅酸钠为硅源,十六烷基三甲基溴化铵为模板剂,采用溶胶-凝胶法合成了负载型硅钨酸/二氧化硅( STA/SiO2)催化剂,并采用红外光谱、氮吸附-脱附、热重对其结构和性质进行了表征。结果表明,所制备的硅钨酸/二氧化硅同时具有微孔和介孔结构,且硅钨酸负载后热稳定性有所提高。以柠檬酸三丁酯的合成作为探针反应,考察了制备催化剂时溶液pH值、硅钨酸负载量对催化剂催化性能的影响。结果表明在pH为9,硅钨酸负载量为50%时,制备的硅钨酸/二氧化硅具有较好的催化活性和重复使用性,该催化剂初次使用时,柠檬酸的转化率在300min可达到89．09%,重复使用6次,柠檬酸的转化率在300min仍可达到86．86%。通过对反应动力学进行研究,发现柠檬酸三丁酯的合成反应为一级反应。
이규산납위규원,십륙완기삼갑기추화안위모판제,채용용효-응효법합성료부재형규오산/이양화규( STA/SiO2)최화제,병채용홍외광보、담흡부-탈부、열중대기결구화성질진행료표정。결과표명,소제비적규오산/이양화규동시구유미공화개공결구,차규오산부재후열은정성유소제고。이저몽산삼정지적합성작위탐침반응,고찰료제비최화제시용액pH치、규오산부재량대최화제최화성능적영향。결과표명재pH위9,규오산부재량위50%시,제비적규오산/이양화규구유교호적최화활성화중복사용성,해최화제초차사용시,저몽산적전화솔재300min가체도89．09%,중복사용6차,저몽산적전화솔재300min잉가체도86．86%。통과대반응동역학진행연구,발현저몽산삼정지적합성반응위일급반응。
A series of silicon tungsten heteropoly acid immobilized on porous silica catalysts( STA/SiO2 ) were synthesized by sol-gel synthesis method with sodium meta-silicate as silica source,CTAB as template. Their structures were characterized by IR,N2 adsorp-tion-desorption and TGA-DSC. The results showed that micro-and meso-porous STA/SiO2 catalysts with good thermal stability were synthesized. The effect of pH value,loading amount of silicon tungsten heteropoly acid on the catalytic activities of STA/SiO2 in tri-butyl citrate synthesis were also studied. The results showed that the STA/SiO2 which was synthesized at pH value 9,the loading a-mount of silicon tungsten hetero-poly acid 50%has good catalytic activity and reusability. The conversion of citric acid reaches 89. 09%in 300 min when STA/SiO2 is first used,and it still remains 86. 86%when it is reused six times. The tri-butyl citrate syn-thesis reaction is first order reaction according to the analysis of chemical kinetics.