Enhanced Hydrogen Generation from Magnesium–Aluminum Scrap Ball Milled with Low Melting Point Solder Alloy

Abstract

In this investigation, composite materials were manufactured of mixed scrap of Mg-based alloys and low melting point Sn–Pb eutectic by high energy ball milling, and their hydrogen generation performance was tested in NaCl solution. The effects of the ball milling duration and additive content on their microstructure and reactivity were investigated. Scanning electron microscopy (SEM) analysis indicated notable structural transformations of the particles during ball milling, and X-ray diffraction analysis (XRD) proved the formation of new intermetallic phases Mg2Sn and Mg2Pb, which were aimed to augment galvanic corrosion of the base metal. The dependency of the material’s reactivity on the activation time and additive content occurred to be non-monotonic. For all tested samples ball milling during the 1 h provided, the highest hydrogen generation rates and yields as compared to 0.5 and 2 h and compositions with 5 wt.% of the Sn–Pb alloy, demonstrated higher reactivity than those with 0, 2.5, and 10 wt.%.

Silver-Assisted Hydrogen Evolution from Aluminum Oxidation in Saline Media

“…Other feasible methods are mainly focused on the modification of aluminum composition and structure. That can be done via its melting together with various metals (e.g., Fe, Sn, Cu, Li, Ga, In, Sn) [ 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ] or ball milling with salts (e.g., NaCl, KCl, NiCl 2 , CoCl 2 ) [ 52 , 53 , 54 , 55 , 56 ], oxides and hydroxides (Bi(OH) 3 , AlOOH, Al(OH) 3 , Al 2 O 3 , TiO 2 , Co 3 O 4 , Cr 2 O 3 , MoO 3 , Bi 2 O 3 , CuO, Cu 2 O) [ 57 , 58 , 59 , 60 , 61 , 62 , 63 ], and metals (Cu, Bi, Sn, Pb, Fe, Ni, Zn, Ga, In) [ 56 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ]. Experiments with aluminum granules and distilled water under 200–280 °C proved that aluminum vulnerability to oxidation was critically dependent on the amount of impurities in aluminum alloys and their nature [ 72 ].…”

Metal Scrap to Hydrogen: Manufacture of Hydroreactive Solid Shapes via Combination of Ball Milling, Cold Pressing, and Spark Plasma Sintering

“…In conductive media, the oxidation of Al and Mg 'mechanically coupled' with 'nobler' metals is accelerated by galvanic corrosion. The latest activation methods were successfully used for the effective utilization of aluminum-and magnesium-based waste materials with hydrogen generation [41][42][43][44].…”