Methane adsorption in ADOR zeolites: a combined experimental and DFT/CC study.

Physical adsorption of methane in purely siliceous molecular sieves prepared by a recently discovered synthetic pathway using 2D zeolites as nanoscale building blocks has been investigated by means of combined experimental and theoretical approaches. The DFT/CC-based method has been tested on ADOR zeolites of the UTL family and a few experimentally well-characterized siliceous zeolites. Excellent agreement between theoretical and experimental heats of adsorption has been found for OKO, PCR, MFI, CHA and AEI zeolites. The observed discrepancy for the UTL germanosilicate (2 kJ mol-1 ) has been plausibly explained using a simple model of D4R defects. The proposed methodology can be used as a reliable characterization tool for newly synthesized silica nanomaterials.