Pd@Cu(II)-MOF-Catalyzed Aerobic Oxidation of Benzylic Alcohols in Air with High Conversion and Selectivity

A new 3D porous Cu­(II)-MOF (1) was synthesized based on a ditopic pyridyl substituted
diketonate ligand and Cu­(OAc)2 in solution, and it features
a 3D NbO motif which is determined by the X-ray crystallography. Furthermore,
the Pd NPs-loaded hybrid material Pd@Cu­(II)-MOF (2) was
prepared based on 1 via solution impregnation, and its
structure was confirmed by HRTEM, SEM, XRPD, gas adsorption–desorption,
and ICP measurement. 2 exhibits excellent catalytic activity
(conversion, 93% to >99%) and selectivity (>99% to benzaldehydes)
for various benzyl alcohol substrates (benzyl alcohol and its derivatives
with electron-withdrawing and electron-donating groups) oxidation
reactions in air. In addition, 2 is a typical heterogeneous
catalyst, which was confirmed by hot solution leaching experiment,
and it can be recycled at least six times without significant loss
of its catalytic activity and selectivity.