Depth-Resolved Imaging of Surfaces and Interfaces in MFI-Type Zeolite Crystals via Multislice Electron Ptychography

Local structural features in zeolites-such as crystal surfaces, interfaces, and defects-critically influence molecular transport and catalysis, yet their nonperiodic nature renders 3D, high-resolution characterization difficult. Here, we show that multislice electron ptychography (MEP) opens new opportunities to address this limitation. Through simulation-guided optimization of acquisition parameters and the use of low electron doses to avoid structural damage, MEP attains atomic-scale lateral and nanometer-scale depth resolution, enabling visualization of diverse local structures in the MFI-type zeolite ZSM-5. This depth sensitivity reveals nanometric surface roughness, [010]/[100] intergrowth with an intervening MEL-type domain, and a previously unreported planar defect involving intra-crystalline translational offsets. These findings highlight pronounced structural inhomogeneity in this widely studied zeolite and demonstrate the potential of MEP for probing 3D nonperiodic structures in other zeolites and in similarly beam-sensitive materials.