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论文类型：期刊论文

发表时间：2018-10-01

发表刊物：MOLECULAR CATALYSIS

收录刊物：SCIE

卷号：458

页面范围：19-24

ISSN号：2468-8231

关键字：Sorbitol; Isosorbide; Dehydration; Silver-exchanged heteropolyacid

摘要：Transformation of renewable biomass into chemicals has attracted much attention recently. Efficient catalytic dehydration of biomass-derived sorbitol into isosorbide over solid acid catalysts under moderate reaction conditions is still a technical challenge. A series of silver-exchanged phosphotungstic acid catalysts were prepared by an ion-exchanged process, and dehydration of sorbitol into isosorbide was performed under solvent-free conditions. More than 99% conversion of sorbitol was obtained with 83% selectivity of isosorbide over Ag1H2PW catalyst at 140 degrees C within 1 h, which are comparable with that using a homogeneous phosphotungstic acid (HPW) catalyst. The silver-exchanged phosphotungstic acid catalysts were characterized by various techniques such as XRD, FT-IR, Raman, NH3-TPD and Py-IR to build a relationship between the catalytic activity and their natures. Ag1H2PW exhibited much higher activity for catalytic dehydration of sorbitol to isosorbide compared with Ag2H1PW and Ag3PW under the same reaction conditions, which was attributed to the stronger acidity and higher amount of Bronsted acid sites. Moreover, Ag1H2PW could be easily regenerated by 65% HNO3 solutions and used repeatedly at least 3 times without obvious loss of catalytic activity.