Liu Xiaoliang, Shi Jing, Yang Guang, Zhou Jian, Wang Chuanming, Teng Jiawei, Wang Yangdong, Xie Zaiku
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai Research Institute of Petrochemical Technology, SINOPEC Corp., Shanghai, China.
China Petrochemical Corporation (SINOPEC Group), Beijing, China.
Commun Chem. 2021 Jul 16;4(1):107. doi: 10.1038/s42004-021-00543-w.
Zeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a morphology effect are challenging to define. Here we introduce a descriptor that accounts for the morphology effect in the catalytic performances of H-ZSM-5 zeolite for C olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar sheet-like morphology but different c-axis lengths were synthesized. We found that the catalytic activity and stability is improved in samples with longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamics simulations, we show that the difference in catalytic performance can be attributed to the anisotropy of the intracrystalline diffusive propensity of the olefins in different channels. Our descriptor offers mechanistic insight for the design of highly effective zeolite catalysts for olefin cracking.
沸石的形态对于确定其催化活性、选择性和稳定性至关重要，但要定义这种形态效应的定量描述符具有挑战性。在此，我们引入了一种描述符，它考虑了H-ZSM-5沸石在烯烃催化裂化中的催化性能的形态效应。合成了一系列具有相似片状形态但c轴长度不同的H-ZSM-5沸石。我们发现，c轴较长的样品的催化活性和稳定性得到了提高。结合时间分辨原位傅里叶变换红外光谱和分子动力学模拟，我们表明催化性能的差异可归因于烯烃在不同通道中晶内扩散倾向的各向异性。我们的描述符为设计用于烯烃裂化的高效沸石催化剂提供了机理见解。
