文献类型：期刊文献

英文题名：Tungsten-promoted titania as solid acid for catalytic hydrolysis of waste bottle PET in supercritical CO2

作者：Guo, Wen-Ze[1];Lu, Hui[1];Li, Xue-Kun[1];Cao, Gui-Ping[1]

机构：[1]E China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, UNILAB, Shanghai 200237, Peoples R China

年份：2016

卷号：6

期号：49

起止页码：43171

外文期刊名：RSC ADVANCES

收录：;EI(收录号：20162102409343);WOS:【SCI-EXPANDED(收录号:WOS:000375611100048)】；

基金：The authors thanks for the support from Shanghai College Students Innovative Entrepreneurial Training Plan Program (S15001) and the assistance of Ye-Xin Du, Zhong-Wang Fu, Ao Xiao and Ren-Jie Tang.

语种：英文

外文关键词：Polyethylene terephthalates - Carbon dioxide - Ethylene - Ethylene glycol - Matrix algebra - Titanium dioxide - Tungsten - Glycerol - Molecules - Plastic bottles - Catalyst activity - Titration

摘要：Tungsten-promoted titania solid acid catalysts were synthesized by a hydrothermal method and used in the hydrolysis of waste bottle polyethylene terephthalate (PET) in supercritical CO2. The structure of the catalytically active sites in this system was determined by XRD, Raman spectroscopy, and HR-TEM. The surface acidity and reduction properties were studied by NH3-TPD, titration experiments, and H-2-TPR. The results indicated that the tungsten phase existed as surface WOx species, and a direct relationship among the number of nanoclusters consisting of polytungstate species on the surface, the number of Bronsted acid sites, and the catalytic activity was discovered. Partial reduction of WOx species in the presence of the ethylene glycol produced during hydrolysis was also observed, and the polytungstate species were easier to reduce with increased condensation. A mechanism was proposed to describe the hydrolysis in which water molecules and hydronium ions were carried by supercritical CO2 and penetrated the swollen PET matrix, and the hydrolysis occurred preferentially in the amorphous region of the surface and bulk of the PET matrix. The results reported here may help to pave the way for the design of active, reusable tungsten-based solid acid catalysts and highly efficient reaction systems for the polyester hydrolysis.