Abstract: The aluminum source is made of Al2(SO4)3 solution, and the precipitant is made of NH4HCO3 solution. By modifying the aging step in the preparation process, the structure of the precursor aluminum ammonium carbonate (AACH) and the calcined γ⁃Al2O3 are modulated, and a high specific surface area nano γ⁃Al2O3 with a hierarchical pore structure was prepared. PtSnK/γ⁃Al2O3 long chain alkane dehydrogenation catalyst was prepared with macro⁃mesostructured hierarchical γ⁃Al2O3 as the carrier. C10―C13 long chain alkanes were used as raw materials to evaluate the activity and stability of the catalyst in a small fixed bed reactor. The results of the study indicated that the γ⁃Al2O3 support obtained after secondary modulation had a macro⁃mesostructured hierarchical pore structure, and the pore size distributions of mesopores and macropores were relatively concentrated. The average pore diameter, pore volume, and specific surface area were 25.40 nm, 2.09 cm3/g, and 284.5 m2/g, respectively. The initial conversion of long⁃chain alkanes dehydrogenation over PtSnK/γ⁃Al2O3 catalyst has reached 26.9% under accelerant condition and after 18 hours can still achieve 21.3%, the dehydrogenation conversion rate is higher than that of commercial alumina.

Key words: Hierarchical, γ?Al2O3, Aluminum ammonium carbonate, Long chain alkanes, Dehydrogenation

摘要： 　铝源采用Al2(SO4)3溶液，沉淀剂采用NH4HCO3溶液，通过改进制备过程中的老化步骤，对前体碳酸铝铵(AACH)和焙烧后的γ⁃Al2O3进行结构调变，制备了具有多级孔结构的高比表面积纳米γ⁃Al2O3。以大孔⁃介孔多级孔结构纳米γ⁃Al2O3为载体，制备了Pt⁃Sn⁃K/γ⁃Al2O3长链烷烃脱氢催化剂。以C10―C13长链烷烃为原料，在小型固定床反应器中考察了催化剂的活性及稳定性评价试验。结果表明，经过二次调变后得γ⁃Al2O3载体具有大孔⁃介孔多级孔结构，并且介孔和大孔孔径分布相对集中，平均孔径、孔容和比表面积分别达到25.40 nm、2.09 cm3/g和284.5 m2/g。Pt⁃Sn⁃K/γ⁃Al2O3催化剂在催速条件下的长链烷烃脱氢初始转化率达到26.9%，连续反应18 h后，转化率仍能达到21.3%，转化率高于商业γ⁃Al2O3催化剂。

关键词: 多级孔, γ?Al2O3, 碳酸铝铵, 长链烷烃, 脱氢