Design of Mg-Cu alloys for fast hydrogen production, and its application to PEM fuel cell

Mg-Cu alloys are designed for fast hydrogen generation by precipitating an electrochemically noble phase (Mg₂Cu) at the grain boundaries. The noble precipitates accelerate the hydrolysis kinetics of the alloy by synergetic action of galvanic and intergranular corrosion. The Mg-3Cu alloy exhibits a hydrogen generation rate of 5.23 ml min⁻¹ g⁻¹, which is 307 times faster than that of pure Mg (0.017 ml min⁻¹ g⁻¹). Furthermore, the effects of annealing of the alloy on the hydrogen generation rate and the feasibility of the production of power via hydrolysis of Mg-3Cu alloy are also confirmed. The annealing of the alloy reduces the hydrogen generation rate through the decrease of precipitates, and 10 g of Mg-3Cu alloy can produce power of 7.25 W for 37 min by operation of a single cell PEMFC.