Creating the hydrogen absorption capability of CeNi5 through the addition of Al

Ability of hydrogen storage CeNi5-xGax and Mg2Ni alloys to hydrogenate acetylene

“…A refraction point occurs at x = 1 in both Figure 3 (a,b): the slope of the lattice expansion increases at x > 1 for the a-axis but decreases in case of the c-axis. A similar trend is observed for CeNi 5-x Al x alloys [4]. The substitution sites changed from the intermediate layer (3g sites) to the basal layer (2c sites) at x = 1 in LaNi 5-x Ga x [13].…”

“…Figure 8 shows the results of catalytic testing and sample weight and surface areas are presented in exhibited much lower reactivity than Mg 2 Ni, as shown in Figure 8. Therefore, the formation of the hydride phase, Mg 2 NiH 4 , reduced catalytic activity in the hydrogenation of C 2 H 2 , in contrast to CeNi 5-x Ga x alloys and previous reports [4,23,24,26,29,[31][32][33][34]36]. After annealing, the Mg 2 NiH 4 disappeared and Mg 2…”

“…The results show that all alloys possess the same hexagonal structure (CaCu 5 -type) with a space group of P6/mmm. In the CeNi 5 structure, Ce atoms occupy vertices site (1a site) and Ni atoms occupy two different atomic sites, one locates on the z = 0 plane (2c site) and the other locates on the z = 1/2 plane (3g site) as shown in Figure 2 [4,40]. Neutron diffraction shows that Ga preferentially substitutes strongly into the 3g sites of CeNi 4 Ga and CeNi 3.5 Ga 1.5 [41].…”

“…Substitution of group 13 elements for Ni may change the hydrogen capacity, equilibrium plateau pressures, and stability of their hydrides. Many intermetallic RENi 5 in which Ni was replaced with Al [4][5][6][7][8][9][10][11][12], Ga [13][14][15][16][17][18], or In [19], have been examined for their potential to improve hydrogen absorption properties. In these IMCs, the equilibrium plateau pressures generally decrease as Ni substitution increases.…”

“…Since the state of absorbed hydrogen is similar to a dissociative hydrogen atom, hydrogen storage alloys have been used as catalysts for hydrogenation of C 2 H 4 and CO 2 [32][33][34][35][36]. Using a hydrogen storage alloy as a catalyst is a new approach to catalysis, however, few studies about hydrogen storage alloys and the selectivity of products from catalysis for hydrogenation of alkynes have been reported [4]. The present study describes the development of a series of CeNi 5-x Ga x alloys as hydrogen storage alloy catalysts and their hydrogen absorption properties and catalytic reactivity upon substitution with Ga.…”