Lu Shenglu, Jing Yaxuan, Feng Bo, Guo Yong, Liu Xiaohui, Wang Yanqin
Shanghai Key Laboratory of Functional Materials Chemistry and Research, Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, No. 130 Meilong Road, Shanghai, 200237, P.R. China.
ChemSusChem. 2021 Oct 5;14(19):4242-4250. doi: 10.1002/cssc.202100196. Epub 2021 Mar 12.
The strong desire for a circular economy makes obtaining fuels and chemicals via plastic degradation an important research topic in the 21st century. Here, the first example of the H -free polyethylene terephthalate (PET) conversion to BTX (benzene, toluene and xylene) was achieved by unlocking hidden hydrogen in the ethylene glycol part over Ru/Nb O catalyst. Among the whole process (hydrolysis, reforming and hydrogenolysis/decarboxylation), the parallel hydrogenolysis and decarboxylation were competing and the rate-determining step. Ru/Nb O exhibited superior hydrogenolysis and poorer decarboxylation performance in direct comparison with Ru/NiAl O , accordingly contributing to the distinct selectivity to alkyl aromatics among BTX. Ru species on Nb O , unlike those on NiAl O , showed more Ru species owing to the strong interaction between Ru and Nb O , restricting the undesired decarboxylation. Along with NbO species for C-O bond activation, excellent reactivity towards the H -free conversion of PET back to BTX with alkyl aromatics as dominant species was achieved. This H -free system was also capable of converting common real PET plastics back to BTX, adding new options in the circular economy of PET.
对循环经济的强烈渴望使得通过塑料降解获取燃料和化学品成为21世纪一个重要的研究课题。在此，通过在Ru/Nb₂O催化剂上释放乙二醇部分中隐藏的氢，实现了首例无氢聚对苯二甲酸乙二酯（PET）转化为BTX（苯、甲苯和二甲苯）。在整个过程（水解、重整和氢解/脱羧）中，平行的氢解和脱羧相互竞争，且为速率决定步骤。与Ru/NiAl₂O₄直接比较，Ru/Nb₂O₄表现出优异的氢解性能和较差的脱羧性能，因此对BTX中烷基芳烃具有明显不同的选择性。与NiAl₂O₄上的Ru物种不同，Nb₂O₄上的Ru物种由于Ru与Nb₂O₄之间的强相互作用而显示出更多的Ru物种，从而限制了不希望的脱羧反应。连同用于C-O键活化的NbO物种一起，实现了以烷基芳烃为主导物种的PET无氢转化回BTX的优异反应活性。这种无氢体系还能够将普通的实际PET塑料转化回BTX，为PET的循环经济增添了新的选择。
