1 research outputs found
Copper-Based Intermetallic Electride Catalyst for Chemoselective Hydrogenation Reactions
The development of
transition metal intermetallic compounds, in
which active sites are incorporated in lattice frameworks, has great
potential for modulating the local structure and the electronic properties
of active sites, and enhancing the catalytic activity and stability.
Here we report that a new copper-based intermetallic electride catalyst,
LaCu<sub>0.67</sub>Si<sub>1.33</sub>, in which Cu sites activated
by anionic electrons with low work function are atomically dispersed
in the lattice framework and affords selective hydrogenation of nitroarenes
with above 40-times higher turnover frequencies (TOFs up to 5084 h<sup>–1</sup>) than well-studied metal-loaded catalysts. Kinetic
analysis utilizing isotope effect reveals that the cleavage of the
H–H bond is the rate-determining step. Surprisingly, the high
carrier density and low work function (LWF) properties of LaCu<sub>0.67</sub>Si<sub>1.33</sub> enable the activation of hydrogen molecules
with extreme low activation energy (<i>E</i><sub>a</sub> = 14.8 kJ·mol<sup>–1</sup>). Furthermore, preferential
adsorption of nitroarenes via a nitro group is achieved by high oxygen
affinity of LaCu<sub>0.67</sub>Si<sub>1.33</sub> surface, resulting
in high chemoselectivity. The present efficient catalyst can further
trigger the hydrogenation of other oxygen-containing functional groups
such as aldehydes and ketones with high activities. These findings
demonstrate that the transition metals incorporated in the specific
lattice site function as catalytically active centers and surpass
the conventional metal-loaded catalysts in activity and stability