A reflection on ‘Flexibility versus rigidity: what determines the stability of zeolite frameworks? A case study’

Abstract

Since their discovery, the quest for novel zeolite materials has led to an inflation of discovered topologies. But what determines the stability and synthetic feasibility of these porous materials? In 2014, Verheyen et al. published a manuscript in Materials Horizons discussing the stability of a new zeolite framework, OKO, from the viewpoint of framework flexibility (Mater. Horiz., https://doi.org/10.1039/C4MH00127C). The present commentary reflects on this work in a broader context, outlining two important criteria contributing to the stability of zeolite crystals, minimization of: (i) internal surface, and (ii) strain. Using examples selected from over a decade of zeolite research, the impact of these aspects is discussed in terms of enthalpic and entropic contributions to the minimization of crystal energy and overall Gibbs free energy of zeolite synthesis systems.