Synthesis, structure and dehydrogenation of zirconium borohydride octaammoniate

Abstract

A new metal borohydride ammoniate (MBA), Zr(BH4)4·8NH3, was synthesized via ammoniation of the Zr(BH4)4 crystal. Zr(BH4)4·8NH3 has a distinctive structure and the highest coordination number of NH3 groups among all the known MBAs. This compound could quickly dehydrogenate at 130 °C, enabling it a potential hydrogen storage material.

Metal‐Borohydride‐Modified Zr(BH4)4⋅8 NH3: Low‐Temperature Dehydrogenation Yielding Highly Pure Hydrogen

“…By exposing the Zr(BH 4 ) 4 crystals to an atmosphere of anhydrous ammonia in a vessel placed in an ice‐water bath for at least 8 h, Zr(BH 4 ) 4 ⋅ 8 NH 3 was obtained as a white powder. The successful synthesis of Zr(BH 4 ) 4 ⋅ 8 NH 3 was confirmed by our previous work 6. Zr(BH 4 ) 4 ⋅ 8 NH 3 – n LiBH 4 mixtures with different molar ratios ( n =2, 4) and Zr(BH 4 ) 4 ⋅ 8 NH 3 – n Mg(BH 4 ) 2 mixtures ( n =1, 2) were mechanically milled for 30 min under argon with a ball‐to‐powder ratio of 30:1.…”

“…Furthermore, Zr(BH 4 ) 4 ⋅ 8 NH 3 has a high hydrogen capacity of 14.8 wt % and a low main dehydrogenation temperature of 130 °C, exhibits impressive air stability, and shows no foaming or expansion on decomposition. These features make it competitive with other B–N‐based hydrides as a promising hydrogen‐storage candidate 6…”

Electrochemical properties of hypo-stoichiometric Y-doped AB 2 metal hydride alloys at ultra-low temperature

“…XRD analysis is a very important tool for the study of energyrelated material sciences [28][29][30][31][32][33][34][35][36][37][38][39]. The XRD patterns of the stoichiometric (Y0-Y5) and hypo-stoichiometric (Y0, Y6-Y10) series are shown in Fig.…”

Ammonia borane modified zirconium borohydride octaammoniate with enhanced dehydrogenation properties

“…[12][13][14] Among them, metal borohydride ammoniates (M(BH 4 ) m $nNH 3 , MBAs), which contain both BH 4 and NH 3 groups and dehydrogenate based on the interaction of the hydridic B-H and protic N-H bonds, release hydrogen at a relatively low temperature with fast dehydrogenation reaction kinetics. 26 Several approaches including additive doping, nano-connement effects from templates and combination methods have been employed to suppress the release of ammonia from many other MBAs. Upon heating, this compound is capable of rapidly releasing hydrogen at 130 C. Hence, Zr(BH 4 ) 4 $8NH 3 is considered as one of the promising chemical hydrogen storage materials.…”