Ishihara Atsushi, Tsuchimori Yuu, Hashimoto Tadanori
Division of Chemistry for Materials, Graduate School of Engineering, Mie University Japan
RSC Adv. 2021 Jun 2;11(32):19864-19873. doi: 10.1039/d1ra02677a. eCollection 2021 May 27.
The dehydrocyclization-cracking of methyl oleate was performed by ZnZSM-5-AlO hierarchical composite-supported Pt catalysts in the range of 450-550 °C under 0.5 MPa hydrogen pressure. Most catalysts converted methyl oleate completely and produced aromatics with more than 10 wt% yield as well as valuable fuels even at 450 °C. The reactivity of catalysts changed remarkably depending on the addition method of Pt, while supporting Pt of 0-0.16 wt% did not affect the pore structure of each catalyst. When Pt was introduced into the composite support by the conventional impregnation method, remarkable hydrocracking proceeded through the decarboxylation and decarbonylation of methyl oleate and the successive conversion of C17 fragments and gave the significant amounts of gaseous products. Nevertheless, the selectivity for the aromatics of the gasoline fraction was relatively high and the yields of aromatics reached maximum 19% at 500 °C under 0.5 MPa, suggesting that gaseous olefins would be cyclized through the Diels-Alder reaction on ZnZSM-5 in the composite support. In contrast, when Pt was introduced into catalysts by ion-exchange with ZnZSM-5, the significant conversion of methyl oleate was inhibited and produced liquid fuels in a wide range.
在0.5 MPa氢气压力下，使用ZnZSM - 5 - AlO分级复合载体负载的Pt催化剂进行油酸甲酯的脱氢环化裂解反应，反应温度范围为450 - 550℃。大多数催化剂即使在450℃时也能将油酸甲酯完全转化，生成产率超过10 wt%的芳烃以及有价值的燃料。催化剂的反应活性根据Pt的添加方法有显著变化，而负载0 - 0.16 wt%的Pt不会影响每种催化剂的孔结构。当通过传统浸渍法将Pt引入复合载体时，油酸甲酯通过脱羧和脱羰基反应以及C17片段的连续转化发生显著的加氢裂化，并产生大量气态产物。然而，汽油馏分芳烃的选择性相对较高，在0.5 MPa、500℃时芳烃产率最高达到19%，这表明气态烯烃会在复合载体中的ZnZSM - 5上通过狄尔斯 - 阿尔德反应环化。相比之下，当通过与ZnZSM - 5进行离子交换将Pt引入催化剂时，油酸甲酯的显著转化受到抑制，并产生广泛范围内的液体燃料。
