Niu Xiaopo, Feng Fuxiang, Yuan Gang, Zhang Xiangwen, Wang Qingfa
Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China.
Nanomaterials (Basel). 2019 Mar 4;9(3):362. doi: 10.3390/nano9030362.
Hollow Silicalite-1 and ZSM-5 zeolites with hierarchical porous shells have been synthesized by using a dissolution-recrystallization method. The morphology, structure, and acidity of these zeolites supported Pt catalysts were characterized by XRD, FT-IR, MAS-SSNMR, FE-SEM, FE-TEM, N₂-BET, XPS, NH₃-TPD, and CO pulse chemisorption. Compared to the conventional ZSM-5 supported Pt catalyst, the special structure in hollow ZSM-5 zeolite significantly promotes the dispersion of metallic Pt and the synergistic effect between metal active sites and acid sites. These boost the catalytic activity, selectivity of guaiacol hydrodeoxygenation toward cycloalkanes and long-term stability over the Pt/hollow ZSM-5 catalyst combined with improved mass transfer of products and reactants derived from the hierarchical hollow porous structure. Moreover, the Pt/hollow ZSM-5 catalyst exhibits excellent low temperature catalytic activity to completely transform guaiacol into cycloalkanes with the cyclohexane selectivity of more than 93% at 220 °C, suggesting that hollow ZSM-5 zeolite is a promising support for upgrading of bio-oils.
采用溶解-重结晶法合成了具有分级多孔壳层的中空硅铝酸盐-1和ZSM-5沸石。通过XRD、FT-IR、MAS-SSNMR、FE-SEM、FE-TEM、N₂-BET、XPS、NH₃-TPD和CO脉冲化学吸附对这些沸石负载的Pt催化剂的形貌、结构和酸性进行了表征。与传统的ZSM-5负载Pt催化剂相比，中空ZSM-5沸石中的特殊结构显著促进了金属Pt的分散以及金属活性位点与酸性位点之间的协同效应。这些促进了催化活性、愈创木酚加氢脱氧制环烷烃的选择性以及Pt/中空ZSM-5催化剂的长期稳定性，同时改善了由分级中空多孔结构产生的产物和反应物的传质。此外，Pt/中空ZSM-5催化剂表现出优异的低温催化活性，能够在220℃下将愈创木酚完全转化为环烷烃，环己烷选择性超过93%，这表明中空ZSM-5沸石是一种有前景的生物油升级载体。
