Computational Insights into Morphology and Interface of Zeolite Catalysts: a Case Study of K-LTL Zeolite with Different Si/Al Ratios

We have developed a computational framework to simulate the external surface structure of zeolites and used it to examine the surface structures and morphology of the K-LTL zeolite system with varying Si/Al ratio. Our calculated result shows that the {100} and {110} surfaces exhibit cancrinite cages and the {001} surface terminates with double six ring cages for each Si/Al ratio of the K-LTL zeolite. HRTEM images verified the calculated result. The Wulff construction presents a hexagonal prism and the length/dimeter ratio of the shape becomes smaller with gradually decreasing Si/Al ratio. Furthermore, we found that Pt metals present hugely different stabilities and electronic properties on the external and inner surfaces. Our computational protocol is easily extended to all other zeolite systems, thereby providing a deeper understanding of morphology modifications and the interfacial interactions between metals and zeolites.