Hydrogen Generation from Highly Activated Al–Ce Composite Materials in Pure Water

Abstract

The reaction of aluminum with pure water is an eco‐friendly approach to generate hydrogen. The main difficulty associated with this approach is that an oxide or hydroxide protective film around aluminum particles prohibit the hydrogen generation. In this article, a kind of highly activated Al–Ce composite material has been developed via a convenient ball milling method. Typically, Al–13 wt% Ce has a total hydrogen production of 1134 mL/g and a conversion yield of 92.42% within 60 min. The influences of the cerium concentration and ball milling time on the hydrogen production efficiency are discussed based on XPS, XRD, FESEM, and BET techniques. In addition, the hydrogen production efficiency can be improved by adding alkali chloride (NaCl or KCl) to the Al–Ce composite materials.

Hydrogen generation by the reaction of Al with water using oxides as catalysts

“…Alloying Al by doping Ga, In, Bi, Sn, etc. [19][20][21][22][23][24][25][26][27][28][29][30][31] and mechanically milling metal Al with special oxide, graphite, or salt powder [32][33][34][35][36][37][38] are the new routes to activate Al, which make Al rapidly react with water under ambient condition. At the same time, ceramic oxide modification is an effective method; the modified Al powder could directly react with water and generate hydrogen at room temperature [39][40][41][42].…”

Role of Ball Milling of Aluminum Powders in Promotion of Aluminum-Water Reaction to Generate Hydrogen

“…studies have reported that BM improves reaction of Al powders with water by modifying the size or specific surface area of Al particles. [2,7,10,13,[18][19][20]22,28,29,47] Among the mentioned studies, some reported that although BM activates Al powders, extended milling after a particular time can decrease the hydrogen yield. [2,10,13,22,28,29,[47][48][49] The twofold effect of BM time remained unexplained in most of the mentioned studies.…”

“…David and Kopac, Zhao et al, and Luo et al discussed that deformation of Al particles by BM promotes the hydrogen production rate, but they did not perform experiments to prove that. [7,18,19] Wang et al observed that a finer grain Al has a higher hydrogen generation rate. [32] They ascribed that to the presence of a LMP metal layer on grain boundaries, which facilitates reaction of Al with water.…”

“…[6] Scientists have accomplished extensive research to promote the reaction of Al with water for hydrogen generation. Ball milling (BM) of monolithic Al powders [2,[7][8][9] or Al powders with low melting point (LMP) metals such as Ga, In, Bi, Hg, and Zn, [10][11][12][13][14][15][16][17] water soluble salts such as NaCl and KCl, [12,13,[18][19][20][21][22] and ceramic powders such as Al 2 O 3 (a), Al 2 O 3 (c), TiO 2 , C, SiO 2 , and Al(OH) 3 [22][23][24][25][26][27][28][29][30] have been considered to activate Al reaction with water.…”

Semisolid Al–Ga composites fabricated at room temperature for hydrogen generation

“…11 Some researchers have tried to activate aluminium by adding Hg, Li, Bi, Ga, In, Sn, Cu, and Ge, which are able to etch aluminium constantly and destroy its oxide layer. [12][13][14][15][16][17][18] It is believed that alloys with a low melting point can be responsible for accelerating the coarsening effect, which increases the variability in the reaction yield of older samples. 19 However, in previous works, these alloys have been usually prepared by heating materials to hundreds of degrees for a long time.…”