“On–Off” Control for On-Demand H₂ Release upon Dimethylamineborane Hydrolysis over Ru_0.8Ni_0.2/MoS₂ Nanohybrids

Abstract

In spite of the fact that remarkable developments are achieved in the design and development of novel nanocatalysts for H2 release upon dimethylamineborane hydrolysis, the development of an “on–off” switch for demand-based H2 evolution upon dimethylamineborane hydrolysis is still a matter of supreme importance, however. Herein, we synthesized a string of MoS2 nanosheet-supported RuNi bimetallic nanohybrids (Ru x Ni1–x /MoS2), by fixation of RuNi nanoparticles at the MoS2 surface, for the H2 evolution upon the hydrolysis of dimethylamineborane at 30 °C. For safely and effectively generating, transporting, and storing H2 gas, the selective “on–off” switch for on-demand H2 evolution upon dimethylamineborane hydrolysis over the Ru0.8Ni0.2/MoS2 nanohybrid has been successfully realized by the Zn2+/EDTA-2Na system. In particular, the H2 evolution is totally switched off by adding Zn(NO3)2. It seems that Zn2+ ions are attached and anchored at the Ru0.8Ni0.2/MoS2 surface, inhibiting their surface-active sites, leading to the termination of H2 evolution. Then, the H2 generation is subsequently reactivated by adding the EDTA-2Na solution because of its excellent coordination ability with Zn2+ ions. This study not only offers a new and efficient RuNi nanocatalyst for dimethylamineborane hydrolysis but also proposes a new method for the demand-based H2 production.

A Solid-System Strategy for Controlled Hydrolytic Release of Hydrogen by Encapsulation of Ammonia Borane in Cobalt Decorated Halloysite Aerogel

“…To sum up, the hydrogen production of AB@Co/HNTA can be controlled by regulating the amount of water added each time, which means that hydrogen can be produced on demand. In order to figure out the influence of the temperature, the controllable hydrogen production performance of AB@Co/HNTA with 20 μL of water per drop at different temperatures (15,25,35, and 45 °C) was studied (Figure 5d). The rate of hydrogen production increases as the temperature increases, indicating that the hydrolysis reaction is endothermic.…”

“…Nevertheless, this process is hard to control, which restricts the on-demand application of hydrogen in a vehicle. To the best of my knowledge, there are few researches focusing on the controlled release of hydrogen from AB hydrolysis at present, and most of the researches concentrate on liquid-phase hydrogen release system. − For example, Chen et al covered the active site of the nanocatalyst with Zn 2+ to prevent hydrogen generation and chelated Zn 2+ with EDTA to reactivate the nanocatalyst, so as to achieve controlled hydrogen release by alternative addition of Zn 2+ and EDTA. Wang et al adopted the alternative addition of HCl and NaOH in the liquid reaction to turn off and on the hydrolysis of AB.…”