Conversion of CH and Hydrogen Storage via Reactions with MgH-12Ni.

The main key to the future transition to a hydrogen economy society is the development of hydrogen production and storage methods. Hydrogen energy is the energy produced via the reaction of hydrogen with oxygen, producing only water as a by-product. Hydrogen energy is considered one of the potential substitutes to overcome the growing global energy demand and global warming. A new study on CH conversion into hydrogen and hydrogen storage was performed using a magnesium-based alloy. MgH-12Ni (with the composition of 88 wt% MgH + 12 wt% Ni) was prepared in a planetary ball mill by milling in a hydrogen atmosphere (reaction-involved milling). X-ray diffraction (XRD) analysis was performed on samples after reaction-involved milling and after reactions with CH. The variation of adsorbed or desorbed gas over time was measured using a Sieverts'-type high-pressure apparatus. The microstructure of the powders was observed using a scanning transmission microscope (STEM) with energy-dispersive X-ray spectroscopy (EDS). The synthesized samples were also characterized using Fourier transform infrared (FT-IR) spectroscopy. The XRD pattern of MgH-12Ni after the reaction with CH (12 bar pressure) at 773 K and decomposition under 1.0 bar at 773 K exhibited MgH and MgNiH phases. This shows that CH conversion took place, the hydrogen produced after CH conversion was then adsorbed onto the particles, and hydrides were formed during cooling to room temperature. Ni and MgNi formed during heating to 773 K are believed to cause catalytic effects in CH conversion. The remaining CH after conversion is pumped out at room temperature.