Immobilization of palladium silver nanoparticles on NH2-functional metal-organic framework for fast dehydrogenation of formic acid

Abstract

Selective dehydrogenation of formic acid is regarded as a universal strategy for providing a clean energy carrier (hydrogen, H2) to reduce the dependence on fossil fuel. In this work, ultrafine PdAg nanoparticles (NPs) are successfully immobilized on NH2-functionalized metal–organic framework MIL-101(Cr) by a facile wet-reduction method. By virtue of amine group, the size of obtained PdAg NPs can be controlled into 2.2 nm, which are monodispersed on NH2-MIL-101(Cr) surface. In addition, the resulting Pd0.8Ag0.2 NPs/NH2-MIL-101(Cr) catalyst systems demonstrate excellent catalytic activity for formic acid decomposition in mild condition, the turn over frequency (TOF) value can achieve as high as 1475 h−1 at 323 K, which is comparable to most of the reported noble metal heterogeneous catalysts for this catalytic reaction under similar conditions. The excellent catalytic kinetics is mainly attributed to the ultrafine size and high dispersion of PdAg NPs. Also, the amine group from NH2-MIL-101(Cr) support facilitates the OH bond dissociation of formic acid and improves the kinetics of formic acid decomposition.