Mechanochemical activation of aluminum with gallams for hydrogen evolution from water

Hydrogen generation from water by means of activated aluminum

“…In addition, the hydrogen yield is lowered for the milling aluminum (it does not exceed 70e80%). These unusual results do not coincide with results received previously for the aluminum granules [27]. We think that this is due to the fact that aluminum wire is initially in energy-intensive state.…”

“…2, curve 1a). The additional highenergy milling (as for aluminum granules in [27]) does not increase reaction rate, even decreases it (Fig. 2, curve 2a).…”

“…The aluminum activation was performed in two steps: 1) preparation of gallam (alloy on basis of gallium); 2) mechanical treatment of preliminarily crushed aluminum wire with gallam in a porcelain mortar [26]. For the activation of aluminum granules (99.9%, average diameter is 10 mm) the third stage was used, which consists of the mechanochemical treatment in high-energy ball mill of materials obtained in the second stage [27]. Mechanochemical activation of the aluminum wires was carried out in the centrifugal ball mill S 100 Retsch.…”

“…The activation was performed in two steps: manual treatment of aluminum granules with gallam (step 1) [25,26] and additional trituration in the high-energy ball mill (step 2) [27]. Such activated aluminum powders reacting with water give high rate of hydrogen production e 1000e2500 mL/ (g min).…”

Hydrogen Generation by Treatment of Aluminium Metal with Aqueous Solutions: Procedures and Uses

“…The activation of aluminium powders by grinding or comilling with gallams of various compositions, Ga-In (70:30), Ga-In-Zn (70:25:3), Ga-In-Sn (62:25:13), Ga-In-Sn-Zn (60:25:10:5), leads to significant rates of hydrogen gas evolution on water contact [31] [32]. These are in the range of 14-20 mL g -1 min -1 with powders prepared by soft mechanical treatments, but can be two orders of magnitude higher, at 1000 -2500 mL g -1 min -1 , in the case of the milled powders.…”