Isomorphous Substitution of Si in Zeolite Single Crystals. Part II. On The Boron Distribution and Coordination In [B]-ZSM-5

FTIR microscope measurements in the transmission mode on single crystal sheets of [B]-ZSM-5 have been used to study the lattice boron distribution and coordination in the crystals. The infrared scans indicate that a homogeneous boron distribution is present in the [B]-ZSM-5 crystals, which contained 0–4 B/uc. A reversible hydration/dehydration experiment with a thin single crystal of [B]-ZSM-5 under the IR microscope led to further attribution of the well known typical 1380 cm −1 and 905 cm −1 absorption bands in the [B]-ZSM-5 spectra. The 905 cm −1 integrated band intensity was used for the quantitative determination of the lattice boron content, the reported asymmetric lattice vibration shift at 1085 cm −1 cannot serve this purpose . [B]-ZSM-5 crystals of different form and morphology were used.