Abstract
The development of alternative and efficient hydrogen production routes remains a critical scientific and technological challenge. One promising approach involves hydrogen generation from water through its interaction with aluminum; however, the presence of a stable oxide layer on the aluminum surface inhibits the reaction under ambient conditions. This study aims to activate the aluminum surface by introducing sodium chloride into aqueous solutions of phosphoric and sulfuric acids and to quantify the hydrogen evolution rate. Experiments were conducted using phosphoric and sulfuric acids, chemical-grade sodium chloride, and A85 aluminum. Hydrogen production was carried out under laboratory conditions using a calibrated glass burettetype setup. The volume of evolved hydrogen was determined by measuring the volume of water displaced from the burette. The addition of sodium chloride to acidic aqueous solutions resulted in the destruction of the aluminum oxide layer and initiated aluminum-water interaction. Localized dissolution induced by chloride ions led to the formation of a porous and heterogeneous surface, significantly enhancing hydrogen evolution. In phosphoric acid solutions (1-7 mol·L -1 ), the hydrogen evolution rate remained low (up to 8 mL·h -1 ·cm -2 ); however, upon addition of sodium chloride (25 g·L -1 ), the rate increased to 50.02 mL·h -1 ·cm -2 , representing a 6.25-fold enhancement. In sulfuric acid solutions (0.5 -2 .5 mol·L -1 ) containing sodium chloride, the hydrogen evolution rate increased from 25.27 to 108.38 mL·h -1 ·cm -2 , corresponding to an approximately fivefold increase. Thus the results demonstrate the feasibility of hydrogen generation on aluminum surfaces at room temperature using acidic aqueous solutions supplemented with sodium chloride. The proposed activation approach relies on inexpensive and readily available reagents and shows potential for autonomous systems hydrogen production, including applications based on aluminum scrap.