The Catalytic Performance of Nanorod Nickel Catalyst in the Hydrolysis of Lithium Borohydride and Dimethylamine Borane

Abstract

In the current global energy crisis, the value of hydrogen has become better appreciated. Metal borohydrides attract a lot of attention from researchers because they are rich in hydrogen. In this study, glass microscope slides were coated with nickel as nanorods for use as a catalyst by the magnetron sputtering method, and then catalytic hydrolysis reactions of dimethylamine borane and lithium borohydride were carried out to produce hydrogen. Parameters such as temperature, the amount of catalyst, lithium borohydride, or dimethylamine borane concentration were varied and their effects on the catalytic performances of the catalyst were examined. Moreover, the catalyst was characterized by field emission scanning electron microscopy and X-ray diffraction, and hydrolysis products were analyzed through field emission scanning electron microscopy with energy dispersive spectroscopy analyses. Reaction kinetic parameters were also determined. The activation energy values of dimethylamine borane and lithium borohydride were determined to be 40.0 kJ mol−1 and 63.74 kJ mol−1, respectively. Activation enthalpy values were also calculated as 37.34 kJ mol−1 and 62.45 kJ mol−1 for dimethylamine borane and lithium borohydride, respectively. Initial hydrogen production rates under different conditions were also investigated in the study. For both hydrolysis systems, the fastest hydrogen production rates were calculated as 109 mL gNi−1 min−1 and 103 mL gNi−1 min−1 for dimethylamine borane and lithium borohydride, respectively, in the experiment performed at 60 °C at 0.2 M substrate concentration and with 1.3 g of catalyst. These hydrolysis systems using this catalyst are good candidates for systems that need hydrogen.