Reanalysis of CO₂-silicalite-1 structure as monoclinic twinning

Abstract

Abstract Structural analysis of CO 2 -silicalite-1 crystals using the single-crystal X-ray diffraction method reveals that the crystal system is twinned monoclinic. The structure of silicalite-1 (MFI-type zeolites) loaded with CO 2 has previously been solved in orthorhombic system [1], but the R value is still large. Since CO 2 molecules are too small to maintain the orthorhombic structure, it is considered that the CO 2 -silicalite-1 crystals should be in the relaxed monoclinic twin phase. The diffraction data in the previous report is recalculated in P 2 1 /n as the monoclinic twinning.