CAJ | 학술논문

用原位合成法制备了不同固载量的磷钨酸催化剂 H3 PW12 O40/SiO2作催化剂,通过FT-IR、XRD等手段对催化剂进行表征.结果表明,在煅烧温度为200℃,活化时间为4 h,H3 PW12 O40负载量为20％时,原位法制备的催化剂在载体孔壁中高度分散的磷钨酸仍然保持了Keggin 特征结构,且与 SiO2材料的表面羟基存在一定的化学相互作用.对苯甲醛1,2-丙二醇缩醛合成的催化性能研究表明,固定苯甲醛用量为0．2 mol,在n(苯甲醛)∶n(1,2-丙二醇)＝1∶1．5,催化剂的用量占反应物料总质量1．0％,环己烷用量为8 mL,反应时间为60min 条件下,产品收率可达88．5％.催化剂使用5次以后,催化活性仍然保持在接近51．7％.
용원위합성법제비료불동고재량적린오산최화제 H3 PW12 O40/SiO2작최화제,통과FT-IR、XRD등수단대최화제진행표정.결과표명,재단소온도위200℃,활화시간위4 h,H3 PW12 O40부재량위20％시,원위법제비적최화제재재체공벽중고도분산적린오산잉연보지료Keggin 특정결구,차여 SiO2재료적표면간기존재일정적화학상호작용.대분갑철1,2-병이순축철합성적최화성능연구표명,고정분갑철용량위0．2 mol,재n(분갑철)∶n(1,2-병이순)＝1∶1．5,최화제적용량점반응물료총질량1．0％,배기완용량위8 mL,반응시간위60min 조건하,산품수솔가체88．5％.최화제사용5차이후,최화활성잉연보지재접근51．7％.
The different loading catalysts of 12-tungstophosphoric acid/SiO2 were prepared by in-situ method. The structure and properties of the catalysts were characterized by FT-IR spectroscopy,X-ray diffraction.It was found that the catalyst containing 20 % H3 PW12 O40 by calcination at 200 ℃ for 4 h showed a higher catalyt-ic activity.The results show that the 12-tungstophoaphoric acid highly dispersed in hole of SiO2 still keeps the Keggin structure,and has certain chemical interaction with surface hydroxy for SiO2 .The catalytic properties of synthetic benzaldehyde 1,2-propanediol acetal show that H3PW12 O40/SiO2 catalyst have high catalytic activity. The optimum conditions are:molar ratio of benzaldehyde to 1 ,2-propylene was 1∶1 .5 ,the mass ratio of the catalyst used to the reactants was 1 .0%,the volume of cyclohexane as the water-carrying agent was 8 mL,and the reaction time was 60 min,the yield of its can reach 88.5%,and show excellent reusabity.