Ru nanoparticles supported on MIL-53(Cr, Al) as efficient catalysts for hydrogen generation from hydrolysis of ammonia borane

Abstract

For the first time, ultrafine Ru nanoparticles are successfully deposited on MIL-53(Cr) and MIL-53(Al) by using a simple liquid impregnation strategy and then characterized the structure, size, composition and specific area of the catalysts with different Ru loading by XRD, TEM, EDX, ICP-AES, XPS and BET. Their catalytic activities had been examined in ammonia borane hydrolysis to generate hydrogen gas. The results show that the as-synthesized 2.65 wt% Ru@MIL-53(Cr) and 2.59 wt% Ru@MIL-53(Al) exhibit the highly catalytic activity, owing to the uniform distribution of Ru nanoparticles and bi-functional effects between Ru nanoparticles and the host of MIL-53. The turn over frequency (TOF) values of the Ru@MIL-53(Cr) and Ru@MIL-53(Al) catalysts are 260.8 and 266.9 mol H2 min−1 (mol Ru)−1 and the activation energies (Ea) are determined to be 28.9 and 33.7 kJ mol−1, respectively. Moreover, the two catalysts exhibit satisfying durable stability after five cycles for the hydrolytic dehydrogenation of ammonia borane.