One of the hallmarks of multicomponent metal–organic
frameworks
(MOFs) is to finely tune their active centers to achieve product selectivity.
In particular, obtaining bimetallic MOF hollow structures with precisely
tailored redox centers under the same topology is still challenging
despite a recent surge of such efforts. Herein, we present an engineering
strategy named “cluster labilization” to generate hierarchically
porous MOF composites with hollow structures and tunable active centers.
By partially replacing zirconium with cerium in the hexanuclear clusters
of UiO-66, unevenly distributed yolk–shell structures (YSS)
were formed. Through acid treatment or annealing of the YSS precursor,
single-shell hollow structures (SSHS) or double-shell hollow structures
(DSHS) can be obtained, respectively. The active centers in SSHS and
DSHS differ in their species, valence, and spatial locations. More
importantly, YSS, SSHS, and DSHS with distinct active centers and
microenvironments exhibit tunable catalytic activity, reversed selectivity,
and high stability in the tandem reaction and the photoreaction.