Hydrogen generation from ammonia borane hydrolysis catalyzed by ruthenium nanoparticles supported on Co-Ni layered double oxides

It is a very challenging task to develop high-performance metal catalysts for hydrolytic dehydrogenation of ammonia borane (AB, NH3BH3). In this work, cobalt-nickel layered double oxide (CoNi-LDO) with a sea urchin-like structure is prepared through the calcination of its corresponding layered double hydroxide (CoNi-LDH). As a catalyst support, ruthenium nanoparticles are loaded on CoNi-LDO by chemical reduction to form Ru/LDO catalysts. The effect of the reduction method (i.e., liquid-phase reduction and gas-phase reduction) and the auxiliary reagent citric acid (CA) on their catalytic properties for hydrogen production from AB hydrolysis is systematically studied. It takes only about 85 s at room temperature for the completion of AB hydrolysis in the presence of the as-prepared Ru-CA/LDO-G catalyst, which exhibits a much lower activation energy (E-a = 25.94 kJ mol(-1)) and relatively higher activity (TOF = 501.4 mol(H2) mol(Ru)(-1) min(-1)). These experimental results are further confirmed by theoretical calculations, during which there is strong adsorption of AB molecules and easy activation of water molecules on Ru/LDO-G. Therefore, Ru/CoNi-LDO as a catalyst exhibits potential application in the field of hydrogen evolution from hydrolysis of hydroborates such as AB and NaBH4.

Automated summary

Developing high-performance metal catalysts for the hydrolytic dehydrogenation of ammonia borane is a challenging task. In this study, a cobalt-nickel layered double oxide (CoNi-LDO) with a sea urchin-like structure was prepared and used as a catalyst support for ruthenium nanoparticles. The study systematically investigated the effect of reduction methods and auxiliary reagents on the catalytic properties for hydrogen production from AB hydrolysis.