377104 Ni-Co/r-GO Catalysts for Hydrogen Generation from Chemical Hydride System Containing Ammonia Borane
Renewable energy attracts more and more attention in recent years. Among various green energies, hydrogen is one of the most promising energy due to its higher efficiency and power density, as well as its environmental benignity. Commonly, the hydrogen energy could be effectively extracted through devices such as fuel cells. Nowadays, the researches related to proton exchange membrane fuel cells (PEMFCs) become one of popular topic because PEMFCs have high energy efficiency and low operation temperature. Hence, the transportation of hydrogen to PEMFCs is the main topic in the future. In general, there are four methods of hydrogen storage: (1) high-pressure tanks; (2) liquefied hydrogen; (3) metal hydrides; and (4) chemical hydrides. Chemical hydrides not only have higher hydrogen storage capacity but also generate hydrogen quickly in the presence of adequate catalysts. Ammonia borane (NH3BH3) is a prospective compound in chemical hydrides. The hydrogen energy density of NH3BH3 is 19.6 wt%. Furthermore, NH3BH3 and its spent products are rarely toxic and flammable.
In this work, NH3BH3 and Ni-Co/r-GO catalysts were pulverized by using high energy ball milling machine (denoted as solid-state AB composite). Reduced graphene oxide (r-GO) was adopted as a light-weighted catalyst support. The Ni-Co/r-GO catalysts were characterized with SEM, EDS, TEM, VSM and ICP-AES. Hydrogen was generated by injecting adequate water from a syringe to initiate the hydrolysis reaction of solid-state AB composite. The amount of water dosage and loading of as-prepared catalysts will be discussed in this study. Hydrogen profiles were recorded by a mass flow meter (MFM) installed on a computer and temperature profiles were observed by a thermocouple at the same time.