Hydrolysis of Ammonia-Borane over Ni/ZIF-8 Nanocatalyst: High Efficiency, Mechanism, and Controlled Hydrogen Release

Non-noble metal nanoparticles are notoriously difficult to prepare and stabilize with appropriate,dispersion, which in ttirn severely limits their catalytic functions. Here, using zeolitic imidazolate framework (ZIF-8) as MOF template, catalytically remarkably- efficient, ligand-free first-row late transition-metal nanoparticles are prepared and compared. Upon scrutiny of the Catalytic principles in the hydrolysis of ammonia-borane, the-highest total turnover frequency among these first-row late transition metals is-achieved for the templated Ni nanoparticles with 85.7 mol(H2) mol(cat)(-1) min(-1) at room temperature, which overtakes performances of previous non-noble metal nanoparticles systems, and is even better than some noble metal nanoparticles systems. Mechanistic studies especially using kitietic isotope effects show that cleavage by Oxidative addition of an O-H bond in H2O is the rate-determining step in this reaction. Inspired by these mechanistic studies, an attractive and effective on-off' control of hydrogen production is, further proposed.