Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F, 3001, Heverlee, Belgium.
Angew Chem Int Ed Engl. 2018 Mar 12;57(12):3074-3078. doi: 10.1002/anie.201711446. Epub 2018 Feb 15.
A new route to lactide, which is a key building block of the bioplastic polylactic acid, is proposed involving a continuous catalytic gas-phase transesterification of renewable alkyl lactates in a scalable fixed-bed setup. Supported TiO /SiO catalysts are highly selective to lactide, with only minimal lactide racemization. The solvent-free process allows for easy product separation and recycling of unconverted alkyl lactates and recyclable lactyl intermediates. The catalytic activity of TiO /SiO catalysts was strongly correlated to their optical properties by DR UV/Vis spectroscopy. Catalysts with high band-gap energy of the supported TiO phase, indicative of a high surface spreading of isolated Ti centers, show the highest turnover frequency per Ti site.
提出了一种生产丙交酯的新途径，丙交酯是生物可降解塑料聚乳酸的关键构建块，涉及在可扩展的固定床装置中通过可再生烷基丙交酯的连续催化气相酯交换反应来实现。负载型 TiO/SiO 催化剂对丙交酯具有很高的选择性，几乎没有丙交酯外消旋化。该无溶剂工艺允许容易地分离产物和回收未转化的烷基丙交酯以及可回收的丙酰中间体。通过 DR UV/Vis 光谱，负载型 TiO/SiO 催化剂的催化活性与其光学性质强烈相关。具有高的负载 TiO 相带隙能量的催化剂，表明孤立 Ti 中心具有高的表面分散性，显示出最高的每钛位的周转频率。
