Amorphous, Embryonic or Mesoporized Zeolites? An Overview of Intermediate Synthetic Phases: Definitions,...

The success of zeolites as catalysts has long been attributed to their high thermal stability and strict shape selectivity flowing from their network of well-defined channels and cages. Synthetic efforts often unjustly disregarded (partially) amorphous intermediate synthetic phases (ISPs), including embryonic zeolite, interzeolite conversion intermediates and mesoporized zeolites, as "failed" and excluded them from further characterization efforts. Recently, this perception has changed and better characterization techniques have led to a deeper understanding of the structure and catalytic potential these materials (may) hold. In this work, we will give a brief overview of the state of the art research being conducted in synthesis, characterization and exploitation of ISPs, as well as clarifying some definitions, hoping to set the stage for future generations of zeolite scientists.