• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>RSC Advances >Tungsten-promoted titania as solid acid for catalytic hydrolysis of waste bottle PET in supercritical CO2
【24h】

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

机译：钨培养的二氧化钛作为超临界CO2中废水瓶催化水解的固体酸

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

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 CO _(2) . 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 NH _(3) -TPD, titration experiments, and H _(2) -TPR. The results indicated that the tungsten phase existed as surface WO _( x ) species, and a direct relationship among the number of nanoclusters consisting of polytungstate species on the surface, the number of Br?nsted acid sites, and the catalytic activity was discovered. Partial reduction of WO _( x ) 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 CO _(2) 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.
机译：通过水热法合成钨钨钛钛腈催化剂，并用于超临界CO_（2）中的废瓶聚乙烯对苯二甲酸乙二醇酯（PET）的水解。该系统中的催化活性位点的结构由XRD，拉曼光谱和HR-TEM测定。通过NH _（3）-TPD，滴定实验和H _（2）-TPR研究了表面酸度和还原性能。结果表明，钨相存在于表面WO _（X）种，以及由表面上的聚钨酸盐物种组成的纳米团簇的数量，BRα上位酸位点和催化活性的直接关系。还观察到在水解过程中产生的乙二醇存在下的WO _（X）物种的部分减少，并且通过增加的缩合，聚钨酸盐物质更容易降低。提出了一种方法来描述通过超临界CO_（2）携带水分子和散氢离子并穿透溶胀的PET基质的水解，并且在表面和大量PET基质的非晶区域中优先发生水解。这里报道的结果可以有助于为设计活性，可重复使用的钨基固体酸催化剂和高效反应系统的设计铺平道路，以及用于聚酯水解的高效反应系统。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号