Abstract:

In recent years, propane dehydrogenation to propylene (PDH) has become the most promising and attractive propylene production technology because the successful large-scale exploitation of shale gas can provide a large amount of cheap propane. Currently, supported PtSn/Al₂O₃ catalysts are mainly used for propane dehydrogenation in industry. In the high temperature reaction of propane dehydrogenation, PtSn nanoparticles are prone to sintering and coke deposition, which causes severe catalyst deactivation. To solve the above problems, we synthesized PtSn/MgAl₂O₄-Sheet catalyst by using MgAl₂O₄-Sheet spinel as support. The catalyst had a large pore size, which was favorable for the adsorption of reactants and the desorption of products in the PDH reaction, and thus improves the activity of the catalyst and reduced the content of coke. Meanwhile, the (111) plane of the MgAl₂O₄ spinel support had a strong interaction with the PtSn nanoparticles, which prevented the sintering of PtSn nanoparticles in the high temperature reaction. In the propane dehydrogenation reaction with the prepared catalyst, the conversion of propane reached 43.2%, the selectivity of propylene reached 95.0%, and the deactivation rate was only 0.008h^-1, which was superior to that with the commercial PtSn/Al₂O₃ catalyst.

Key words: propane dehydrogenation, PtSn catalyst, morphology control, propylene, MgAl₂O₄ spinel

摘要：

近年来，因为页岩气大规模开采的成功可以为丙烷脱氢制丙烯（PDH）工艺提供大量廉价的丙烷，丙烷脱氢制丙烯已成为最有前途和最具吸引力的丙烯生产技术。目前工业上丙烷脱氢主要采用的是负载型PtSn/Al₂O₃催化剂。然而在丙烷脱氢高温反应中，PtSn纳米粒子易烧结和积炭使催化剂遭受严重的失活。为了解决上述问题，本文合成了片状的MgAl₂O₄尖晶石载体负载PtSn金属纳米粒子，制备了PtSn/MgAl₂O₄-sheet催化剂。该催化剂具有较大的孔径，有利于PDH反应中反应物的吸附和产物的脱附，提高了催化剂的活性同时降低了积炭含量。同时片状的MgAl₂O₄尖晶石载体的（111）面与PtSn纳米颗粒存在着强的相互作用，阻止了PtSn纳米颗粒在高温反应中的烧结。在丙烷脱氢反应中，丙烷的转化率达到了43.2%，丙烯的选择性达到了95.0%，失活速率仅为0.008h^-1，其性能优于商用的PtSn/Al₂O₃催化剂。

关键词: 丙烷脱氢, 铂锡催化剂, 形貌控制, 丙烯, 镁铝尖晶石