Deposition of Pd nanoparticles on 2D Ni–Fe-MOF ultrathin nanosheets for efficient N-alkylation of amines by alcohols under visible light

Abstract

2D Ni–Fe-MOF ultrathin nanosheets (NSs), with dimensions of ca. 1.0 μm and thickness of ca. 5.0 nm, were successfully fabricated. Small-sized Pd nanoparticles of ca. 3.0 nm were deposited on 2D Ni–Fe-MOF NSs to afford Pd/Ni–Fe-MOF NSs, which were used as an efficient multifunctional catalyst to realize the N-alkylation reactions of amines by alcohols under visible light. The superior performance observed over the resultant Pd/Ni–Fe-MOF NSs as compared with Pd/bulk Ni–Fe-MOF, their 3D counterpart, can be ascribed to the ultrathin nanosheet morphology of 2D Ni–Fe-MOF NSs, which not only shortens the transportation path for the photogenerated charge carriers, but also can provide more efficient interaction between the active site and substrates. This work provides a green and sustainable strategy for the production of secondary amines using alcohols as the alkylating agent. This study also demonstrates the unique advantages of 2D MOF ultrathin nanosheets in the fabrication of multifunctional catalytic systems for light initiated one-pot tandem/cascade reactions.