Search

Li–Mg–B–H reactive hydride composite (RHC) has attracted extensive attention over the past decades for its extremely high hydrogen storage capacity (11.5 wt%). But the sluggish desorption kinetics for the second step dehydrogenation reaction need to be further improved. Herein, short rod-like TMTiO 3 (TM = Co, Ni) bimetallic oxides, which contain two kinds of transition metal elements, were synthesized and introduced into Li–Mg–B–H RHC for the first time. The NiTiO 3 exhibits excellent catalytic effect on the hydrogen desorption kinetic performance of Li–Mg–B–H RHC, and the incubation period for the second step dehydrogenation reaction is eliminated completely by reducing the apparent activation energy for the generation of MgB 2 from 296 kJ/mol to 269 kJ/mol. The NiTiO 3 doped Li–Mg–B–H RHC can desorb about 9.0 wt% H 2 without obvious attenuation of kinetic performance in five cycles. Mechanism analyses reveal that the in-situ generated nano-sized MgNi 3 B 2 and TiB 2 species (∼5 nm) both meet the critical value (< 10%) of the edge-to-edge matching model (5.77% for MgNi 3 B 2 and 2.22% for TiB 2), which play a significant role in supporting the nucleation of MgB 2. Meanwhile, the extremely fine MgNi 3 B 2 and TiB 2 heterogeneous nucleation sites can inhibit the excessive growth for a single crystal nucleus of MgB 2. The heterogeneous nucleation and grain refinement mechanisms caused by the novel bimetallic oxide could provide alternative insights into designing an in-situ generated nano-sized catalytic hydrogen storage system with enhanced kinetics and cyclic stability for hydrogen-fueled applications. Image 1 • Short rod-like NiTiO 3 eliminates the incubation period of dehydrogenation. • In-situ generated MgNi 3 B 2 and TiB 2 nano-species support the nucleation of MgB 2. • Fine MgNi 3 B 2 and TiB 2 nucleation sites cause the grain refinement of MgB 2. [ABSTRACT FROM AUTHOR]

ZrCo alloy has been considered as a tritium storage material to replace uranium for large-scale hydrogen isotope storage and delivery in tritium plant of the magnetic confinement nuclear fusion reactor. However, the disproportionation of ZrCo greatly obstructed its aspects to engineering application. A multifaceted understanding about the intrinsic nature of disproportionation reaction, and proposing anti-disproportionation strategies from material design have always been the bottleneck and hotspot in the tritium science and technology field. Herein, we studied the anti-disproportionation properties of Zr(Ti)Co alloy with thin film structure, and the effects of film thickness and Ti substitutions on the anti-disproportionation properties of the films were obtained. Firstly, a series of ZrCo films with different deposited time were prepared by magnetron sputtering instrument. The disproportionation ratio of the 2 h deposited ZrCo film (1.641μm) is 23.9%, and attenuated with the increase of film thickness. It indicates that the anti-disproportionation properties of the film structure is significantly better than that of ZrCo particle (68%). The microtopography analysis shows that the micro stress in the film structure is beneficial to hinder the disproportionation process. However, the hydrogenation reaction is also obviously inhibited in the ZrCo film. In addition, Ti doping can further improve its anti-disproportionation performance (10.3–7.3% for the 2 h deposited Zr 1-x Ti x Co film) without significantly reducing the hydrogen absorption capacities of the ZrCo flims. The anti-disproportionation performance is closely related to the weakened interaction between Zr and H atoms, after Ti doping into the ZrCo flim, leading to the impaired driving force for disproportionation reaction. The study in this work can provide an important reference for the anti-disproportionation modification of ZrCo alloys. • Hydrogen storage performance of ZrCo with film structure were investigated. • Anti-disproportionation behavior of ZrCo film is related to thickness. • Anti-disproportionation properties of ZrCo film is better than that of particles. • The Ti doping improve the anti-disproportionation performance of ZrCo films. • The Ti enhancement mechanism was obtained from the perspective of binding energy. [ABSTRACT FROM AUTHOR]

The performance of uranium as a hydrogen storage material has attracted much attention. Herein, the hydrogen absorption properties of depleted uranium in impure hydrogen containing He, Ar, CH 4 , N 2 , CO, CO 2 and O 2 were studied by PVT method and XPS analysis. When these impurity gases were mixed in H 2 at low concentrations (0.1%∼1.5%), their behavior can be classified into three categories. The He, CH 4 and Ar were chemically inert to the activated uranium powder under room condition. These three gases inhibited the absorption kinetics during the whole stage by hindering the diffusion of H 2 molecules, showing a blanketing effect. The N 2 and O 2 did not affect the absorption kinetics but reduced the capacity by forming nitrides and oxides. The poisoning effect of N 2 was weaker than that of O 2. The CO and CO 2 not only affected the hydrogen absorption capacity, but also strongly inhibited the absorption kinetics. These two gases are chemically adsorbed on the uranium surface to form passivation layers, thus inhibiting the adsorption and dissociation of H 2 molecules and the diffusion of H atoms. The poisoning and retardation effect of CO 2 were much stronger than that of CO. The above conclusions are important to further study the reactivity of mixed gas with uranium, and can also be used as a reference for other hydrogen storage systems. [Display omitted] • The absorption of impure hydrogen by uranium was investigated. • Seven common impurity gases correspond to three kinds of mechanisms. • Blanketing effect inhibits the dynamics process. (He, CH 4 , Ar). • Poisoning effect reduces the hydrogen absorption capacity. (N 2 , O 2). • CO and CO 2 show poisoning & retardation effect. [ABSTRACT FROM AUTHOR]

Nanoconfining hydrogen storage material inside nanopores has emerged as an intriguing strategy to influence the material characteristics but also sacrifices part of system gravimetric and volumetric hydrogen capacity. Herein, we tackle these two challenges by nanoconfining LiBH 4 into a new scaffold, zeolite-templated carbon (ZTC), with high porosity and excellent mechanical stability to form a densified nanoconfinement system. After nanoconfinement of LiBH 4 and 750 MPa densification, the nanocomposite begins to release hydrogen at 194 °C, 181 °C lower than that of the bulk LiBH 4 . The rehydrogenation of LiBH 4 achieves under mild conditions with improved cycle stability. Moreover, the activation energy of hydrogen desorption is dramatically reduced by 60.4 kJ mol −1 , coupled with the foaming effect of desorption almost eliminated. More importantly, the over-infiltrated LiBH 4 @ZTC systems are capable of maintaining their good hydrogen storage performances, which is attributed to the interface/surface effect between hydrides and scaffolds. With ultra-high pressure densification and high uploading amount of LiBH 4 , the nanoconfined composite achieves an exceptional gravimetric capacity of 6.92 wt% and volumetric capacity of 75.43 g L −1 . These findings add new insights in the development of nanoconfinement systems with enhanced hydrogen storage capacity. [ABSTRACT FROM AUTHOR]

We designed a state-of-art catalyst Ni@C-MXene, which provides ample Ni and Ti active sites to significantly promote the hydrogen storage performance of MgH 2. Experimental methods and theoretical calculations reveal that the in-situ formed Ti0 facilitates the mutual transformation of Mg 2 Ni/Mg 2 NiH 4 , which is called "facilitated hydrogen pump" effect in this work. [Display omitted] • Monolayer MXene was used as the functional carrier to undertake Ni nanoparticles derived from Ni-MOFs. • Striking improvements in hydrogen storage properties were achieved for MgH 2 when the catalyst was added. • DFT calculations revealed the effect of in-situ formed Ti0 on the Mg 2 Ni/Mg 2 NiH 4 mutual transformation. • A concept of "facilitated hydrogen pump" effect was proposed. A novel catalyst—MOFs derived Ni nanoparticles dispersed on exfoliated monolayered MXene functional carrier was prepared and introduced into MgH 2 in this work. Striking improvements in hydrogen storage properties were achieved for MgH 2 when the catalyst was added. Concisely, the hydrogen releasing peak temperature of the MgH 2 + 10 wt% Ni@C-MXene is 241.1 °C, about 120.2 °C lower than that of the additive-free MgH 2. According to Kissinger method, the dehydrogenation activation energy of the MgH 2 + 10 wt% Ni@C-MXene composite is calculated to be 54.79 kJ mol−1, over 60% lower when compared with the pristine MgH 2 (145.08 kJ mol−1). At 300 °C, the MgH 2 + 10 wt% Ni@C-MXene composite releases about 5.6 wt% hydrogen within 2 min, while only 2 wt% hydrogen is desorbed even the dehydriding time prolongs to 60 min for the pure MgH 2. In addition, the completely dehydrogenated MgH 2 + 10 wt% Ni@C-MXene exhibits eminent hydrogen absorption performance, with approximate 5 wt% hydrogen uptaken within 2 min under 3.2 MPa hydrogen pressure at 150 °C. Moreover, an excellent hydrogen cycling stability is achieved in the MgH 2 + 10 wt% Ni@C-MXene without decay for both capacity and kinetics after 10 cycles. Beside the regular XRD, XPS and TEM techniques to clarify the evolution of Ni and Ti during hydrogen de/absorption cycling, more importantly we performed the first principle based calculations to reveal how the in-situ formed Ti0 would affect the Mg 2 Ni/Mg 2 NiH 4 mutual transformation. Apart from the nano confinement effect of MXene for Ni/Mg 2 Ni/Mg 2 NiH 4 , the in-situ formed Ti0 from MXene also favors the "hydrogen pump" effect of Mg 2 NiH 4 due to the decreased formation energy E f under the assistance of Ti0. Through such a synergistic "nano-confinement and facilitated hydrogen pump" effect, the hydrogen de-/absorption kinetics of MgH 2 is significantly accelerated. [ABSTRACT FROM AUTHOR]

Hydrogen isotope (deuterium and tritium) as a special form of hydrogen energy, its storage in an efficient and safe way has been paid more and more attention by researchers in recent years. ZrCo alloy is regarding as the one and only promising material for large-scale storage of hydrogen isotope. However, poor cycle life and inferior capacity retention restrict its engineering application. Herein, we propose a co-substitution strategy of Nb (for Zr) and Ni (for Co) in ZrCo alloy to overcome the defects. Significantly, Zr 0.8 Nb 0.2 Co 0.8 Ni 0.2 alloy exhibits ultralong cycle life (97.6% retention) and remarkable capacity (2.42 H (f. u.)) in 100 cycles, which far exceeds all existing hydrogen isotope storage alloys (Pd, U and other ZrCo-based alloys). These outstanding performances are entirely revealed from two aspects: stable homogeneous structural phase transformation process of parent structure (Zr 0.8 Nb 0.2 Co 0.8 Ni 0.2 H 0.3 -B33 ↔ Zr 0.8 Nb 0.2 Co 0.8 Ni 0.2 H 2.8 -B33″) and ordered migration mechanism of H atom (layered and linear de-/intercalation). Our attractive insights into the ultralong cycle life of ZrCo-based alloys through homogeneous structural phase transformation will serve as a pioneer on cycle optimization in the field of hydrogen storage materials. [Display omitted] • The as-cast alloy containing B33 phase was successfully prepared according co-substitution strategy. • Zr0.8Nb0.2Co0.8Ni0.2 shows the highest cycle capacity and retention among all reported alloys. • The splendid cycle stability comes from B33↔B33'' homogeneous structural phase transformation. • A novel H migration mechanism is proposed to replenish the classical site occupation theory. [ABSTRACT FROM AUTHOR]

Fast heat and mass delivery with high cycling stability of the core component, hydrogen storage bed, in SDS are essential for the operation of the future tritium factory in ITER project. However, the aforementioned properties are still perplexing in large-capacity ZrCo bed, especially for that with secondary containment structure required by the actual tritium operation in the future. Herein, the performance including heating, cycling and cooling with two different size ZrCo beds (loading of ZrCo are 200 g and 2000 g respectively) were systematically studied. The experimental data shows that the maximum heating ability of the middle-size/full-scale storage bed are both about 10 °C/min, and the maximum hydrogen absorption capacity of these ZrCo beds are 44.6 L/405.5 L, respectively. Besides, hydrogen pressure and hydrogen retention during the following desorption can affect the cycling performance of the ZrCo bed. The use of transfer pump can reduce the pressure of the bed during the hydrogen desorption process (operated at 500 °C), which inhibits the disproportionation reaction of the ZrCo alloy. However, the degree of hydrogen pressure reduction in two the types of ZrCo bed are different. As a result, the cycling capacity of the middle-size bed (93.4%, lower hydrogen pressure) is higher than the full-scale bed (68.7%, higher hydrogen pressure) after 10 cycles. When the transfer pump was not used and operated at lower temperature (350 °C), the beds cannot release hydrogen completely, and partial hydrogen atoms are retained in the ZrCo alloy. The middle-size bed still maintains a hydrogen storage capacity of 94.5% after 10 cycles, while 75.9% of the hydrogen storage capacity remained for the full-scale bed. Therefore, the increase of hydrogen surplus in ZrCo alloy is helpful to improve its cycling stability. At last, the cooling performances of the beds under 10 different cooling methods were studied. Among the cooling methods, the best cooling rate was achieved by filling nitrogen in the secondary containment cavity and flowing water passing through the cooling circuit of the bed. This work will provide a crucial reference for the design and optimization of the subsequent operation technology of SDS in ITER. • Thin double-layered annulus ZrCo bed with secondary containment cavity is manufactured. • Real-time pumping transfer helps to improve the circulation stability of the ZrCo bed. • Keep remaining H in the ZrCo is benefits to improve its cycling stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen poisoning behaviors and mechanisms for ZrCo and Pd-coated ZrCo were revealed. • Atomic diffusion reaction to form Pd 3 Zr occurs during high-temperature vacuuming. • Coherent Pd/Pd 3 Zr@ZrCo structure was constructed by regulating heating parameters. • Excellent cycling stability was achieved with novel Pd/Pd 3 Zr@ZrCo structure. As a promising candidate for hydrogen isotopes storage, ZrCo alloy suffers tremendously from the poisoning of impurity gases, especially in oxygen-containing atmospheres, but related effective modification method for long cycling durability is still lacking. In this work, the anti-oxygen-poisoning behaviors and mechanisms of virginal ZrCo and palladium-coated ZrCo with different heating evacuation methods were detailly investigated. Notably, the phase transition occurs during traditional heating evacuation (550 °C for 60 min) with the gradual generation of Pd 3 Zr from original Pd coating and ZrCo substrate. According to absorption behaviors and degeneration state of O π p -orbital peak from theoretical calculations, O 2 undergoes spontaneous dissociation and strong hybridization at the surface of ZrCo and Pd 3 Zr, especially for ZrCo, while much weak surface absorption is recognized on Pd. Considering the superior anti-poisoning properties but weak substrate anchoring strength of Pd, it's valuable to reconstruct the Pd/ZrCo interface to generate transition Pd 3 Zr layer that is less susceptible to hydrogen embrittlement. Accordingly, a coherent structure of Pd/Pd 3 Zr@ZrCo was successfully obtained by high temperature short time pretreatment (550 °C for 10 min), and its cycling capacity retention in O 2 -containg hydrogen atmosphere is significantly enhanced from initial 74.87 % after 5 cycles to 90.83 % after 10 cycles, which is superior to Pd-plating hydrogen storage alloys ever reported. The interface reconstruction of coherent structure proposed here can function as a promising strategy for construction of protective layer for all related surface engineering. [ABSTRACT FROM AUTHOR]

Cycling stability of ZrCo–H system is extremely important for the long-term operation of the storage and delivery system (SDS) in ITER. Herein, the optimal cycling operation parameters were systematically investigated. It indicates that various parameters, such as hydrogen pressure, temperature, composition, and stoichiometric ratio of H atoms, will all affect the cycling performance of the ZrCo–H system significantly. The decline rate of the hydrogen capacity of the ZrCo–H system is positively correlated with the hydrogen pressure. The experimental result shows that 54% of hydrogen capacity decreases under 28.1 kPa hydrogen pressure, while 30% of attenuation is obtained when the pressure is decreased to 8.1 kPa after 14 cycles. In terms of temperature, the lowest cycling attenuation can be maintained at about 25% after 14 cycles when the dehydrogenation temperature at 550 °C. The effects of doping elements, Hf and Ti, on the cycling stability of ZrCo–H system are also compared. The Zr 0.8 Ti 0.2 Co sample exhibits higher cycling capacity than ZrCo and Zr 0.8 Hf 0.2 Co samples. The extremely excellent behavior can be achieved when all ZrCo alloys are continuously evacuated during the hydrogen release process, and the attenuation of only 1.1% is observed for Zr 0.8 Ti 0.2 Co after 15 cycles. Besides, the cycling attenuation is related to residual stoichiometric ratio of H atoms in ZrCo alloy during the cycling test. When the residual H atoms proportion exceeds 1 in ZrCo during dehydrogenation, hydrogen cycling capacity hardly fades. The XRD results reveal that the disproportionation of ZrCo is directly associated with the cycling degradation, yielding the more stable products of ZrCo 2 and ZrH 2 , However, the disproportionation can be avoided during the cycling process by controlling the stoichiometric ratio of H atoms remained in ZrCo above 1. This study demonstrates that the cycling performance of ZrCo can be substantially improved when the operation parameters are properly adjusted, which provides a significant important reference for durable running of SDS in ITER. • Relationship between cyclic property and operation parameters of ZrCo is revealed. • Residual H ratio above 1 in ZrCo after desorption indeed improves cyclic stability. • Cycling capacity retention ratio maintains at ~99% for the optimized parameter. [ABSTRACT FROM AUTHOR]

The solvent-free amorphous Mg(BH 4) 2 composite was in-situ synthesized by ball milling LiBH 4 and MgCl 2. It is found that the onset dehydrogenation temperature of the as-synthesized composite is 126.9 °C, which is roughly 156 °C lower than that of pristine Mg(BH 4) 2. The activation energy of the amorphous Mg(BH 4) 2 and pristine Mg(BH 4) 2 for the first dehydrogenation step was calculated as 120.01 kJ/mol and 487.99 kJ/mol, respectively. Hence the kinetics improvement is certified by the lower E a value of the dehydrogenation process. When adding NbF 5 into the composite, the catalyzed composite exhibits better hydrogen storage properties compared to pristine and amorphous Mg(BH 4) 2. The catalyzed composite starts to release hydrogen at proximately 120 °C with a total capacity of 10.04 wt%. The reversibility of the catalyzed composite is also improved. The capacity of the catalyzed composite at the second cycle is 5.5 wt%. For the third and fourth cycles the catalyzed composite can still liberate 4 wt% H 2. Besides, the onset hydrogen desorption temperature during four cycles are extremely lower than those of pristine and amorphous Mg(BH 4) 2. The peaks of the intermediate MgB 12 H 12 is detected by FTIR as the regenerated hydrogenation product in the catalyzed composite. It can be speculated from the detailed analysis that there are mainly three reasons for the improved properties. Firstly, the additive NbF 5 is favorable to enhance the hydrogen storage properties by modifying the dehydrogenation path and producing MgF 2 and NbB 2 as new products. Secondly, the in-situ formation of amorphous Mg(BH 4) 2 is likely to improve the dehydrogenation properties of the samples due to its different reactivity comparing to crystal ones. Finally, LiCl can serve as buffer in the composite and thus improve the dehydrogenation properties. • Amorphous Mg(BH 4) 2 was in-situ synthesized by ball milling. • NbF 5 changes the dehydrogenation path of Mg(BH 4) 2 and produces MgF 2 and NbB 2. • MgB 12 H 12 is regenerated through hydrogenation process in the sample. • The chloride in the sample can serve as buffer during de/rehydrogenation. [ABSTRACT FROM AUTHOR]

To ensure the safety and efficiency of hydrogen isotopes in the storage and delivery system (SDS), Zr-Mn-V based hydrogen isotopes storage alloys were prepared by induction levitation melting technique under Ar atmosphere. The effects of modification for Zr-Mn-V alloy of ZrMn 2-x V x (x = 0, 0.4, 0.6, 0.8) and ZrMn 1.4-y V 0.6 (y = 0, 0.2, 0.4) on microstructure, hydriding kinetics, de-/hydrogenation thermodynamics, cycling stability and anti-disproportionation performance were systematically investigated. The results show that all alloys contain a main phase of ZrMn 2 and little impure phase. Crucially, the lattice parameters of ZrMn 2 phase increase after V substitution, as well as Mn decrease, leading the equilibrium pressure of dehydrogenation significantly decreases from 2.931 bar (ZrMn 2 -H) to 0.080 bar (ZrMn 1.2 V 0.6 -H) at 200 °C, and the corresponding enthalpy changes from 43.29 to 60.38 kJ mol−1 H 2. Compared with ZrCo, ZrMn 1.2 V 0.6 exhibits outstanding stability with 1.63 wt% during 20 cycles and scarcely losing on capacity through the anti-disproportionation measurement under the simulated SDS environment. Consequently, considering all the performances of ZrMn 1.2 V 0.6 sample, it could be an alternative material for hydrogen isotopes storage and delivery to be applied in SDS. • The lattice parameters of ZrMn 2 phase increases with increasing of V and reducing of Mn. • Zr-Mn-V based samples show excellent hydriding kinetics at room temperature. • The hydrogenation equilibrium pressure decreases with increasing of V and reducing of Mn. • ZrMn 1.2 V 0.6 exhibits outstanding cycling stability and anti-disproportionation performance. [ABSTRACT FROM AUTHOR]

Abstract Nowadays, catalytic doping has been regarded as one of the most promising and effective methods to improve the sluggish kinetics of magnesium hydride (MgH 2). Herein, we synthesized Ni/TiO 2 nanocomposite with the particle sizes about 20 nm by an extremely facile solvothermal method. Then, the Ni/TiO 2 nanocomposite was doped into MgH 2 to enhance its reversible hydrogen storage properties. A remarkably enhancement of de/rehydrogenation kinetics of MgH 2 can be achieved by doped with Ni/TiO 2 nanocomposite, compared to that solely doped with Ni or TiO 2 nanoparticles. The hydrogen desorption peak temperature of MgH 2 Ni/TiO 2 is 232 °C, which is 135.4 °C lower than that of ball-milled MgH 2 (367.4 °C). Moreover, the MgH 2 Ni/TiO 2 can desorb 6.5 wt% H 2 within 7 min at 265 °C and absorb ∼5 wt% H 2 within 10 min at 100 °C. In particular, the apparent activation energy of MgH 2 Ni/TiO 2 is obviously decreased from 160.5 kJ/mol (ball-milled MgH 2) to 43.7 ± 1.5 kJ/mol. Based on the analyses of microstructure evolution, it is proved that metallic Ni particles can react with Mg easily to form fine Mg 2 Ni particles after dehydrogenation, and the in-situ formed Mg 2 Ni will transform into Mg 2 NiH 4 in the subsequent rehydrogenation process. The significantly improved hydrogen absorption/desorption properties of MgH 2 Ni/TiO 2 can be ascribed to the synergistic catalytic effect of reversible transformation of Mg 2 Ni/Mg 2 NiH 4 which act as "hydrogen pump", and the multiple valence titanium compounds (Ti4+/3+/2+) which promote the electrons transfer of MgH 2 /Mg. Highlights • Ni/TiO 2 with particle sizes ∼20 nm was synthesized and doped into MgH 2. • MgH 2 Ni/TiO 2 starts to release hydrogen at 190 °C with ∼6.5 wt% H 2. • Enhanced hydrogen storage properties are due to synergistic catalytic mechanism. [ABSTRACT FROM AUTHOR]

• The research interest of different hydrolytic H 2 production materials is analyzed meticulous in recent 15 years. • The dis-/advantages of the new-classified four kinds of hydrolyzed materials are summarized systematically. • Application prospect of hydrolytic H 2 production materials is discussed in-depth in terms of cost and H 2 yield. Hydrogen energy is regarded as an important part of low carbon energy, which has broad application prospects in the fields of fuel cell, metallurgy, fuel gas and chemical industry. The upstream of hydrogen industry chain is hydrogen production. In the long-term planning, large-scale hydrogen will be obtained by water electrolysis with renewable energy. Since the infrastructure construction of hydrogen is inadequate nowadays, the safe and stable acquirement of hydrogen (especially in some temporary or portable hydrogen usage scenario) is still one of the problems that need to be solved urgently. Hydrogen production technology by reaction of inorganic materials with water is efficient, safety and environmentally friendly. Obviously, the material is the core of the hydrogen production by hydrolysis. Although researchers have done a lot of studies on hydrolytic hydrogen production materials, comprehensive reviews on all these materials are rare. In this paper, the research progress of hydrolytic hydrogen production materials in recent 15 years is investigated systematically and all materials were reclassified into four system (active metals, metal hydrides, borohydrides, silicon and its composites) according to the characteristics of hydrolysis. The dis-/advantages on hydrogen production performances and technical bottlenecks of different materials are all-sided analyzed. Moreover, several promising candidates are singled out based on the in-depth discussion about industrialization feasibility combined with the cost of raw materials and hydrogen production performances. In general, the hydrolytic hydrogen production materials have the characteristic of "on-demand" and "integrated hydrogen storage and transportation", which would be an indispensable part of the field of hydrogen production in the coming future. [ABSTRACT FROM AUTHOR]

LiBH 4 is a promising hydrogen storage material for its large capacity. However, high desorption temperature, sluggish kinetics and demanding rehydrogenation severely hinder its practical use. Surface functional groups of graphene in many cases are treated as effective approaches to obtain some kinds of excellent properties of energy storage materials. In the current work, a new facile and effective strategy to improve the reversible hydrogen desorption properties of LiBH 4 is proposed by composing with functionalized graphene to form the LiBH 4 –fluorographene composite. The fluorographene (FG) nanosheets are successfully exfoliated from fluorographite (FGi) and composed with LiBH 4 . It is demonstrated that the FG can remarkably improve the hydrogen desorption thermodynamics, kinetics and reversibility of LiBH 4 via reactant destabilization method. An extremely fast hydrogen desorption process with a high capacity of 8.2 wt.% at 148.1 °C is achieved in the LiBH 4 –50FG composite. Further research reveals that the enhancement actually roots in the strengthened interfacial interaction between LiBH 4 and exfoliated FG. Moreover, it is confirmed that the LiBH 4 –40FG composite exhibits a significantly enhanced reversible hydrogen desorption capacity of 7.2 wt.% and LiBH 4 is regenerated. Such enhanced reversible hydrogen desorption properties are ascribed to the strengthened interfacial interactions between LiBH 4 and FG with large surface, as well as the formation of LiH x F 1− x phase. [ABSTRACT FROM AUTHOR]