(583br) Hydrogen Generation From Ammonia Borane in Presence of Ni-Co/Gns Catalysts

Chemical hydrides are known to have a relatively higher hydrogen storage capacity and are able to supply ultra-pure hydrogen on-demand from the hydrolysis reactions in the presence of adequate catalysts. Among various chemical hydrides, ammonia borane (NH₃BH₃) has drawn much research attention as its intrinsic hydrogen content is as high as 19.6 wt%.

In this work, a proper light-weighted graphene-based catalyst was developed to catalyze hydrolysis of ammonia borane for hydrogen evolution. Explicitly, graphene oxide (GO) was used as the catalyst support. Subsequently, the electroless deposition technique was applied to grow Ni-Co nanoparticles, as the active catalyst, onto graphene nanosheets (GNS), denoted as Ni-Co/GNS. The Ni-Co/GNS catalysts were characterized with modern instruments, including SEM/EDS, TEM, SQUID/VSM and ICP-AES.

To increase the gravimetric hydrogen storage density, water has to be a limiting agent. Hence, NH₃BH₃ and Ni-Co/GNS catalysts were pulverized and well mixed by using high a high-energy ball mill. Hydrogen profiles were recorded with a mass flow meter (MFM) installed on a computer and temperature profiles of the reacting system were monitored simultaneously. Variable process parameters such as infusion rate of water, the amount of water dosage, and the loading of catalysts are studied and discussed.