Incorporation of Al atoms in particular sites in the ZSM‐5 structure is governed by the Si/Al ratio during synthesis, and their distribution over the twelve types of tetrahedral sites (T1–T12) during crystallization occurs in a nonrandom manner according to the results of 27Al MAS NMR measurements on a series of as‐made ZSM‐5 zeolites with Si/Al=14–250. Further support for this conclusion was provided by 27Al MQMAS spectra (see picture) simulated with X‐ray diffraction data.

Zr-doped LiCoO 2 cathode materials for lithium ion batteries were synthesized by an ultrasonic spray pyrolysis method. The synthesized powders with less than 1 mol% Zr had a single phase layered structure while those with 5 mol% Zr had a little secondary phase, Li 2 ZrO 3 . The cycle stabilities of Zr-doped and undoped LiCoO 2 were compared at various charge-discharge rates. The Zr-doped LiCoO 2 showed much improved cycle stability compared to the undoped, especially at a high C-rate of 3C (4.2 mA/ cm 2 ). To investigate the reasons of the improvement, changes of the lattice parameters and the interatomic distances of Co-Co and Co-O of the doped and the undoped powders were analyzed using XRD and EXAFS. The lattice parameters, a and c, increased in the powders with less than 1 mol% Zr, but decreased in the powder with 5 mol% Zr. On the other hand, the interatomic distances of Co-Co and Co-O did not change with Zr doping. From these results, the improved cycle stability is thought to be due to the expanded inter-slab distance, which enhances Li-ion mobility during charge/discharge processes.

Many important properties of aluminosilicate zeolites, most notably their Br˘nsted acidity and hence catalytic performance, depend primarily on the framework Al content, that is, the extent of isomorphous substitution of Si by Al. However, even in materials with the same framework structure and composition, the location of catalytically active sites can differ according to the manner in which Al atoms are spatially distributed over the available tetrahedral sites (T-sites) in a given zeolite lattice. Therefore, detailed knowledge of the local ordering of Al atoms in these microporous materials is the starting point for systematically manipulating the distribution of acidic sites within the pore architecture.Zeolite ZSM-5 (MFI topology) is one of the industrially most important zeolites. It typically crystallizes in the orthorhombic space group Pnma, and 12 crystallographically distinct T-sites with equal populations exist in the ZSM-5 framework. [1] A fundamental, recurring question regarding this type of zeolite structure is whether the acidic sites (that is, Al atoms on T sites) are spatially ordered. Recently, Olson et al. [2] carried out Rietveld refinement of synchrotron powder X-ray diffraction (XRD) data on a Cs-ZSM-5 zeolite with 5.8 Al atoms per unit cell (Si/Al 15.6) and showed that Cs ions are located in three different extraframework sites. They speculated that Al atoms may be unequally distributed over the 12 distinct T-sites of the ZSM-5 framework. However, because of the very similar scattering powers of Si and Al for X-rays and the difficulties in obtaining large single crystals, especially at high Al concentrations, it is very difficult, or even impossible, to directly locate Al atoms by conventional diffraction methods. Although many quantum chemical studies have also addressed this issue, [3] the nature of

The reliable in-line monitoring of pharmaceutical processes has been regarded as a key tool toward the full implementation of process analytical technology. In this study, near-infrared (NIR) spectroscopy was examined for use as an in-line monitoring method of the paracetamol cooling crystallization process. The drug powder was dissolved in ethanol-based cosolvent at 60°C and was cooled by 1°C/min for crystallization. NIR spectra acquired by in-line measurement were interpreted by principal component analysis combined with off-line characterizations via X-ray diffraction, optical microscopy, and transmission electron microscopy. The whole crystallization process appeared to take place in three steps. A metastable form II polymorph of paracetamol was formed and transformed into the stable form I polymorph on the way to the growth of pure form I by cooling crystallization. These observations are consistent with a previous focused beam reflectance method-based study (Barthe et al., Cryst Growth Des 8:3316-3322, 2008).