Li Weijie, Qin Bin, Dong Zhuoya, Chai Yuchao, Wu Guangjun, Ma Yanhang, Wang Meng, Liu Xingwu, Ma Ding, Li Landong
Key Laboratory of Advanced Energy Materials Chemistry of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, China.
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
Natl Sci Rev. 2024 Aug 27;11(11):nwae305. doi: 10.1093/nsr/nwae305. eCollection 2024 Nov.
The direct epoxidation of propylene with molecular oxygen represents a desired route for propylene oxide (PO) production with 100% theoretical atomic economy. However, this aerobic epoxidation reaction suffers from the apparent trade-off between propylene conversion and PO selectivity, and remains a key challenge in catalysis. We report that Ti-Beta zeolites containing isolated framework Ti species can efficiently catalyze the aerobic epoxidation of propylene. Stable propylene conversion of 25% and PO selectivity of up to 90% are achieved at the same time, matching the levels of industrial ethylene aerobic epoxidation processes. H-terminated pentacoordinated Ti species in Beta zeolite frameworks are identified as the preferred active sites for propylene aerobic epoxidation and the reaction is initiated by the participation of lattice oxygen in Ti-OH. These results are expected to spark new technology for the industrial production of PO toward more sustainable chemistry and chemical engineering.
用分子氧将丙烯直接环氧化是环氧丙烷（PO）生产的理想途径，理论原子经济性可达100%。然而，这种有氧环氧化反应在丙烯转化率和PO选择性之间存在明显的权衡，仍然是催化领域的一个关键挑战。我们报道，含有孤立骨架钛物种的钛-β沸石能有效催化丙烯的有氧环氧化反应。同时实现了25%的稳定丙烯转化率和高达90%的PO选择性，达到了工业乙烯有氧环氧化工艺的水平。β沸石骨架中的氢端基五配位钛物种被确定为丙烯有氧环氧化的首选活性位点，反应由晶格氧参与Ti-OH引发。这些结果有望催生出用于PO工业生产的新技术，朝着更可持续的化学和化学工程发展。
