Continuous Control over Zeolite Porosity via the Post-Synthesis Treatment of the IWV Zeolite

The control over microporosity is crucial for the practical application of zeolites. Here, we report a series of daughter zeolites with related structure prepared via the ADOR (assembly-disassembly-organization-reassembly) post-synthesis of the germanosilicate <b>IWV</b> zeolite. Concentrated HCl was selected as the hydrolysis medium because of its superior efficiency in the disassembly of the <b>IWV</b> zeolite framework and the ordering preservation. The treatment of the <b>IWV</b> zeolite (Si/Ge = 7.5) at room temperature yielded the formation of an intermediate with preserved silicate layers while contracted interlayer spacing (d₂₀₀) via the selective removal of Ge-rich double-four ring (D4R) units. The subsequent treatment at elevated temperatures stimulated the continuous expansion of the interlayer spacing and the reinsertion of siliceous D4R dopants, leading to a series of daughter zeolites with related structures, including the ultimate restored siliceous <b>IWV</b> structure. The d₂₀₀ values and textural properties (surface area and micropore volume) of the daughter zeolites monotonically increase with the heating duration, followed by approaching a maximum. In this context, these parameters can be continuously regulated simply by adjusting the heating durations. Moreover, similar correlations are observed when different heating temperatures or parent <b>IWV</b> zeolites with different Ge contents were utilized, proving the versatility of the present approach.