咪唑-磷钨酸杂化固体酸催化纤维素水解为葡萄糖

合成一种咪唑-磷钨酸杂化固体酸1-（3-磺酸基）丙基-3-甲基咪唑磷钨酸盐（MIMPS] 3PW12O40）,并将其应用于催化纤维素的水解反应之中.与H2SO4,HCl,对甲苯磺酸（p-TSA）以及H3PW12O40相比,MIMPS] 3PW12O40的催化活性与反应选择性都更佳.通过单因素法对反应温度、反应时间、催化剂用量、固液比等进行考察与优化,结果发现：在453 K下,n（MIMPS]3PW12O40）∶n（纤维素）=5.8％时,即可极大地促进纤维素链的断裂、解离和水合;水解反应仅3h后,还原糖和葡萄糖的产率分别为34.0％,21.0％.此外,调节反应体系的pH值约为2时,催化剂以固体沉淀的方式得以回收,且经过5次重复利用后仍能保持良好的催化性能.

Catalytic Hydrolysis of Cellulose into Glucose Using an Imidazolium-Phosphotungstate Hybrid Solid Acid

A kind of imidazolium-phosphotungstate hybrid solid acid had been synthesized,which was 1-（3-sulfonic acid） propyl-3-methyl imidazolium phosphotungstate （MIMPS] 3PW12O40）,and then it was applied into the catalytic hydrolysis of cellulose.MIMPS]3PW12O40 showed higher catalytic activity and selectivity than H2SO4,HCl,p-toluenesulfonic acid （p-TSA） as well as H3PW12O40.The effect factors of the hydrolysis of cellulose had been investigated and optimized in details,such as reaction temperature,reaction time,catalyst dosage and solid-to-liquid ratio.The results illustrated that the optimized reaction conditions were described as follows：the hydrolysis of cellulose was catalyzed by 5.8％ （mol） of MIMPS] 3PW12O40 for 3 h at 453 K in water,affording total reducing sugar（TRS） and glucose in 34.0％ and 21.0％ yield,respectively,wherein chain rupturion,dissociation and hydration of cellulose were promoted greatly by the n （MIMPS] 3 PW12 O40） ∶ n （cellulose） =5.8 ％.Furthermore,the catalyst MIMPS] 3 PW12O40 had been recycled from the reaction system through a simple method of adjusting pH value to around 2 after quenching the reaction,which was reused for five times with little loss of activity.