posted on 2024-01-30, 04:15authored byShoukang Xiao, Li Wang, Ze Qin, Xiao Chen, Liyu Chen, Yingwei Li, Kui Shen
Highly ordered mesoporous
materials with a single-crystalline structure
have attracted broad interest due to their wide applications from
catalysis to energy conversion/storage, but constructing them with
good controllability and high yields remains a highly daunting task.
Herein, we construct a new class of three-dimensionally ordered mesoporous
SnO2 single crystals (3DOm-SnO2) with well-defined
facets and excellent mesopore tunability. Mechanism studies demonstrate
that the silanol groups on ordered silica nanospheres (3DO-SiO2) can induce the efficient heterogeneous crystallization of
uniform SnO2 single crystals in its periodic voids by following
the hard and soft acid and base theory, affording a much higher yield
of ∼96% for 3DOm-SnO2 than that of its solid counterpart
prepared in the absence of 3DO-SiO2 (∼1.5%). Benefiting
from its permanent ordered mesopores and favorable electronic structure,
Pd-supported 3DOm-SnO2 can efficiently catalyze the unprecedented
sequential hydrogenation of 4-nitrophenylacetylene to produce 4-nitrostyrene,
then 4-nitroethylbenzene, and finally 4-aminoethylbenzene. DFT calculations
further reveal the favorable synergistic effect between Pd and 3DOm-SnO2 via moderate electron transfer for realizing this sequential
hydrogenation reaction. Our work underlines the crucial role of silanol
groups in inducing the high-yield heterogeneous crystallization of
3DOm-SnO2, shedding light on the rational design and construction
of various 3DO single crystals that are of great practical significance.