A series of unconventional nano-sized Zn-doped ZnZrO-x catalysts are applied for the first time to the direct dehydrogenation of isobutane to isobutene.

Oligomerization of light olefin is an effective method to produce plentiful liquid fuels. However, oligomerization processes using microporous zeolites have severe problems due to steric hindrance. In this paper, oligomerization of butene using a series of new types of hierarchical HZSM-5 zeolite catalysts is studied. To obtain the modified HZSM-5 catalysts, HZSM-5 is treated with the same concentration of LiOH, NaOH, KOH, and CsOH aqueous solutions, respectively. It is demonstrated that the alkali treatment can effectively modify the acidity properties and hierarchical structure of the HZSM-5 catalyst, which is confirmed by X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Nitrogen Adsorption-desorption Measurements, Transmission Electron Microscopy Investigations (TEM), Ammonia Temperature-programmed Desorption Method (NH 3 -TPD), Pyridine FT-IR, and Thermogravimetric Analysis (TGA). The results show that hierarchical catalysts with interconnected open-mesopores, smaller crystal size, and suitable acidity can better prolong the catalyst lifetime during butene oligomerization. Particularly, the HZSM-5 catalysts treated with CsOH aqueous solution (ATHZ5-Cs) proved to be the most effective catalyst, resulting in approximately 99% conversion of butene and exhibiting C 8 + selectivity of 85% within 12 h. Thus, an appropriate hierarchical catalyst can satisfy the oligomerization process and has the potential to be used as a substitute for the commercial ZSM-5 catalyst.

In this study, the effective active sites of aged ferrierite(FER) were confirmed to be located in the 10‐membered ring (10‐MR) pore mouths by modification with ammonium hexafluorosilicate((NH4)2SiF6 )and long‐term experiments. Analysis of SiO2/Al2O3 ratios showed that aluminum atoms were selectively removed from the FER surface after the modification with (NH4)2SiF6. Comparison of the catalytic properties before and after modification showed that the catalytic activity of aged FER depended only on the amount of acid sites located in the 10‐MR pore mouths. Monitoring of the change in acid amount with reaction time and the difference between aged and deactivated FER showed that aged FER retained only weak acid sites, and its deactivation was caused by carbon deposition on the 10‐MR pore mouth acid sites. Therefore, the catalytic performance of FER can be improved by increasing the number of 10‐MR pore mouths.

Nano-hierarchical ferrierite(FER) was successfully synthesized by using pyrrolidine as sole organic structure directing(OSDA) agent under static hydrothermal conditions.SEM images showed that the morphology of the product was a loose threestage accumulation structure by nano-rod crystal grains .The influence of crystallization temperature, gel alkalinity, crystal-lization time and the amount of OSDA on synthesis of FER was investigated in detail.Moreover,FER catalytic performance in nbutene skeletal isomerizatio was investigated.The results showed that, compared with the commercial FER, the nanohierarchical FER showed better catalytic activity.