Powder X-ray Diffraction Analysis of Zeolites and Contribution to the Development of a Multi-purpose Pattern Fitting System

Abstract

Zeolites having various properties such as molecular adsorption, molecular sieves and solid-acids are widely used industrially as one of the major inorganic nanoporous materials. Powder X-ray diffraction is the most powerful structural analysis method because most porous materials can only be synthesized as polycrystalline powder. This article briefly describes some of our structural studies on novel zeolites, layered silicates, organic-inorganic hybrid porous materials determined by ab-initio structure analysis using powder X-ray diffraction data. In addition, improvement of the function of Rietveld analysis software was indispensable for the determination of these complex crystal structures. In the past development of multipurpose program RIETAN, we have incorporated many functions such as split-type profile functions, composite background function, MEM-based pattern fitting, and Le Bail method. This enables the highest level of pattern fitting for all angular dispersion powder diffraction patterns and enables efficient ab-initio structure analysis.