【摘要】 针对传统正构烷烃加氢异构催化剂微孔孔道窄、扩散阻力大、活性位点利用率低等问题，通过无机/有机混合碱改性制备了多级孔Pt/SSZ-32系列催化剂，探究了改性时间对多级孔催化剂物相结构、孔结构、酸性和酸量、以及其催化正十六烷加氢异构性能的影响。结果表明：有机碱的加入避免了无机强碱对分子筛骨架的过度脱Si和脱Al,形成的介孔孔径更小、更均匀，减少了酸性位点的损失，提高了分子筛内部活性位点的可及性和反应产物的传质能力。随着混合碱改性时间的增加，改性形成介孔的孔体积和比表面积不断增大，骨架Al占比下降而非骨架Al占比增加，催化剂酸量和酸强度均降低，催化剂活性下降；分子筛最佳混合碱改性时间为10 min,该改性条件下制备的催化剂上的加氢异构反应选择性最高，而加氢裂解反应选择性最低，在270℃下异构十六烷的收率达73.6%。通过调控混合碱改性时间可以实现对催化剂加氢异构活性和选择性的有效调控。更多还原

【Abstract】 To address the issues of narrow micropores, high diffusion resistance, and low utilization of active sites in traditional n-alkane hydroisomerization catalysts, a series of hierarchical porous Pt/SSZ-32 catalysts were prepared by inorganic/organic mixed base modification. The effects of different modification times on the phase structure, pore structure, acidity and acid content of the hierarchical porous catalyst, as well as the catalytic performance in the hydroisomerization of n-hexadecane were investigated. The results showed that the addition of an organic base avoided excessive desilication and dealumination of the molecular sieve framework by the inorganic strong base, resulting in smaller and more uniform mesopores, reducing loss of acid sites, and improving the accessibility of active sites within the molecular sieve and the mass transfer capacity of the reaction products. With the increase of mixed base modification time, the pore volume and specific surface area of the modified mesopores continuously increase, while the proportion of framework Al decreases and the proportion of non-framework Al increases. This leads to a decrease in both the acidity and acid strength of the catalyst, resulting in a decline in catalyst activity. The optimal mixed base modification time for the molecular sieve is 10 min. Under this modification condition, the catalyst prepared exhibits the highest selectivity for hydroisomerization and the lowest selectivity for cracking reactions, achieving a 73.6% yield of isohexadecane at 270 ℃. Therefore, the hydroisomerization activity and selectivity of the catalyst can be effectively controlled by adjusting the mixed base modification time.更多还原