Effect of LDH composition on the catalytic activity of Ru/LDH for the hydrolytic dehydrogenation of ammonia borane

Abstract

The hydrolytic dehydrogenation of ammonia borane (NH3-BH3, AB for short) in the presence of catalysts has been identified to be a safe and efficient way for hydrogen release. Understanding the dehydrogenation mechanism of AB is helpful and important to design efficient catalysts. So far, although the effects of various factors on dehydrogenation of AB have been studied, such as the noble metal particle size effect, crystal-phase effect and the support crystal plane effect, the effect of support composition on dehydrogenation of AB has rarely been reported yet. In this study, we choose composition-adjustable layered double hydroxide (MgAl-LDHs) as support for Ru nanoparticles, and use the as-prepared catalysts for comparing their catalytic activity towards the dehydrogenation of AB. The catalytic results demonstrate the catalytic activity of Ru/MgAl-LDHs is related to MgAl-LDHs composition, exhibiting a support-composition effect in the hydrolytic dehydrogenation of AB. Combining various characterizations, the different composition of MgAl-LDHs has an effect on the interaction between Ru nanoparticles and MgAl-LDHs, which directly affects the catalytic activity for the hydrolysis of AB. This study provides new important fundamental knowledge on the mechanism of AB hydrolysis over practical supported metal catalysts which can be used for a better catalyst design.