Direct exfoliation
of layered zeolites into solutions of monolayers
has remained unresolved since the 1990s. Recently, zeolite MCM-56
with the MWW topology (layers denoted mww) has been exfoliated directly
in high yield by soft-chemical treatment with tetrabutylammonium hydroxide
(TBAOH). This has enabled preparation of zeolite-based hierarchical
materials and intimate composites with other active species that are
unimaginable via the conventional solid-state routes. The extension
to other frameworks, which provides broader benefits, diversified
activity, and functionality, is not routine and requires finding suitable
synthesis formulations, viz. compositions and conditions, of the layered
zeolites themselves. This article reports exfoliation and characterization
of layers with ferrierite-related structure, denoted bifer, having
rectangular lattice constants like those of the FER and CDO zeolites,
and thickness of approximately 2 nm, which is twice that of the so-called
fer layer. Several techniques were combined to prove the exfoliation,
supported by simulations: AFM; in-plane, in situ, and powder X-ray
diffraction; TEM; and SAED. The results confirmed (i) the structure
and crystallinity of the layers without unequivocal differentiation
between the FER and CDO topologies and (ii) uniform thickness in solution
(monodispersity), ruling out significant multilayered particles and
other impurities. The bifer layers are zeolitic with Brønsted
acid sites, demonstrated catalytic activity in the alkylation of mesitylene
with benzyl alcohol, and intralayer pores visible in TEM. The practical
benefits are demonstrated by the preparation of unprecedented intimately
mixed zeolite composites with the mww, with activity greater than
the sum of the components despite high content of inert silica as
pillars.