As an environmentally friendly cleaning agent, Z -1-chloro-3,3,3-trifluoropropene (HCFO-1233zd( Z )) can realize industrial production by the isomerization of HCFO-1233zd( E ). Herein, various isomerization catalysts with different structures, compositions and acid properties were prepared through the fluorination of γ-Al 2 O 3 with CHF 3 by controlling the activation conditions. For the first time, the catalysts for HCFO-1233zd( E ) isomerization were systematically studied by XRD, N 2 physisorption, XPS, SEM, MAS NMR spectroscopy, NH 3 -TPD and py-IR. The active site of this reaction was revealed and the catalyst deactivation mechanism was proposed. It turned out that HCFO-1233zd( E ) isomerization prefers to occur at Lewis acid sites with moderate density and strength. The amorphous particles composed of γ-Al 2 O 3 , Al 2 O 3 (F) and α-AlF 3 ( R 3 ¯ c ) at 450 °C exhibit highly catalytic activity for HCFO-1233zd( E ) isomerization. After 100 h evaluation, it was found that residual γ-Al 2 O 3 can be fluorinated by HCFO-1233zd( E ) to form needle-like structures which could induce the amorphous Al 2 O 3 (F) particles to reorganize and give cubic structures, where the Lewis acid properties were enhanced, leading to catalyst deactivation.
Synthesis of highly-crystallized ZSM-48 zeolite with low SiO 2 /Al 2 O 3 ratio was successfully performed via seed-assisted route. The influence of various factors on the seed-assisted synthesis was investigated systematically, including the seeds dosages, different seeds species, adding order of seeds, hydrothermal temperature and time, silica and aluminum sources, and gel compositions. The crystallinity, morphology, textural and acidic properties of ZSM-48 were characterized by various techniques, such as XRD , SEM, FTIR, Py-IR, N 2 physisorption , 29 Si and 27 Al MAS NMR. Aluminum sources posed a critical influence on the crystallinity with NaAlO 2 more beneficial to obtain well-crystallized ZSM-48, whereas the crystallinity seemed slightly susceptible to silica sources. SEM results revealed that the crystal size was significantly reduced from ca. 20 μm to around 2 μm after introduced the seeds. Kinetic analysis suggested that the added seeds can significantly reduce the apparent activation energy of nucleation and crystallization, encourage the formation of crystal nuclei and promote crystallization. The Pt-supported seed-assisted samples exhibited considerably higher density of acid sites than that loaded on seed-free sample. The hydroisomerization of n -hexadecane was investigated over various Pt-supported catalysts, and the Pt-supported seed-assisted samples exhibited the highest i-C 16 yield of ca. 75 wt% at conversion over 87 wt%.