In Situ Quantitative Imaging of Nonuniformly Distributed Molecules in Zeolites

Accurate assessment of molecular uptake and interactions at pore surfaces is crucial for advancing functional porous materials. However, these processes are governed by the intricate interplay of geometry constraints, local electric fields, and operational conditions, requiring in situ atomic-resolution characterization. Here, we present sub-angstrom-resolution (0.76 Å) and linear-phase-response imaging of zeolites and adsorbed benzene molecules across varying atmospheric conditions using in situ electron ptychography. Environment-induced crystal mis-tilts and low electron beam coherence were effectively corrected to maintain high resolution. We established a linear relationship between image phase changes and the number of adsorbed molecules, enabling molecule quantification within individual pores under varying benzene vapor pressures. Depth analysis revealed nonuniform molecular adsorption along pore channels, with guest molecules preferentially accumulated near Al-enriched regions. Our findings provide a general strategy for investigating localized molecular behaviors on the atomic scale in complex environments relevant to industrial catalysis and separation processes.