Pd[sbnd]Ni nanoparticles supported on MIL-101 as high-performance catalysts for hydrogen generation from ammonia borane

Abstract

Mono-metal Pd, Ni and highly dispersed bimetallic PdNi alloy nanoparticles with different molar ratio supported on MIL-101 have been successfully synthesized by a simple liquid impregnation-reduction method. And XRD, TEM, EDX, ICP-AES, XPS, BET and FTIR were employed to characterize the above catalysts. Their catalytic activities were tested in the hydrogen generation from aqueous solution of ammonia borane at room temperature. The results show that the as-synthesized Pd10Ni6@MIL-101 catalyst exhibits the highest catalytic activity, with a total turn over frequency (TOF) value of 83.1 mol H2 min−1 (mol Pd)−1, and the activation energy (Ea) was determined to be 31.7 kJ mol−1. The excellent catalytic activity has been successfully achieved thanks to the strong bimetallic synergistic effects from PdNi nanoparticals of the composites, uniform distribution of nanoparticles as well as bifunctional effects between PdNi alloy nanoparticles and the host of MIL-101. In particular, this catalyst shows satisfying durable stability after five cycles for the hydrolytic dehydrogenation of ammonia borane.