Hydrogen Storage In MgH2 Research Articles

Effect of co-doping graphene and anthracite on hydrogen storage of Mg/MgH2

Carbon materials have been proven to have a favorable impact on the amelioration of the comprehensive characteristics of MgH2 hydrogen storage. Herein, A graphene and anthracite co-doping magnesium (hereafter referred to as Mg–C–G) composite was produced using mechanical ball milling to evaluate the influence of co-doping various types of carbon on the hydrogen storage of Mg/MgH2. It is demonstrated that the co-doping of graphene and anthracite markedly lowered the dehydrogenation peak temperature of MgH2 and optimized its desorption kinetics. The apparent activation energy of the Mg–C–G composite for hydrogen desorption is 94.2 kJ/mol, less than that of pure magnesium by 18.3 kJ/mol. Furthermore, the Mg–C–G composite still maintained 3.72 wt% of hydrogen storage ability after 20 hydrogen uptake and release cycles, achieving a 90.5 % retention rate of hydrogen capacity. This study reveals the impact of carbon species on Mg/MgH2 hydrogen storage, which is a guideline for the design of novel Mg-carbon hydrogen storage systems.

(TiVZrNb)83Cr17 high-entropy alloy as catalyst for hydrogen storage in MgH2

High-entropy alloys (HEAs) hold the promise as excellent catalysts to improve the hydrogen storage properties of MgH2 due to their distinctive compositional and structural characteristics and superior room-temperature hydrogen storage performance. In this work, the (TiVZrNb)83Cr17 HEA was successfully designed and synthesized. Moreover, different amounts of the (TiVZrNb)83Cr17 HEA were introduced into MgH2 as catalysts by ball milling to prepare MgH2-x wt% (TiVZrNb)83Cr17 (x = 3, 6, 10) composites. MgH2-6 wt% (TiVZrNb)83Cr17 composite showed excellent hydrogen absorption and desorption properties. At 573 K, the composite can rapidly absorb 5.3 wt% H2 within 5 min, and even at 523 K, it can still absorb 4.0 wt% H2 within 60 min. Also, it can rapidly desorb 6.0 wt% and 4.1 wt% H2 within 60 min at 623 K and 573 K, respectively. In addition, the MgH2-6 wt% (TiVZrNb)83Cr17 composite possessed relatively low activation energy for hydrogen absorption (70.6 kJ/mol H2) and desorption (90.5 kJ/mol H2). Moreover, the capacity retention was as high as 98.5 % after 10 hydrogen de/absorption cycles at 573 K. Interestingly, (TiVZrNb)83Cr17 HEA transformed from the as-prepared biphasic structure (FCC + BCC) to the hydrogenated single-phase structure (FCC) in the hydrogenation process and returned to the initially biphasic structure (FCC + BCC) in the desorption process, which provided more diffusion pathways for H and more nucleation sites for Mg/MgH2. The multi-element (TiVZrNb)83Cr17 HEA catalyst realized the synergistic catalysis of the hydrogen ab/de-sorption of Mg/MgH2. Our findings provide useful insights into the design and development of HEAs catalysts for improving the hydrogen storage properties of MgH2.

Hydrogen Release and Uptake of MgH2 Modified by Ti3CN MXene

MgH2 has a high hydrogen content of 7.6 wt% and possesses good reversibility under normal conditions. However, pristine MgH2 requires a high temperature above 300 °C to release hydrogen, with very slow kinetics. In this work, we utilized Ti3CN MXene to reduce the operating temperature and enhance the kinetics of MgH2. The initial temperature of MgH2 decomposition can be lowered from 322 °C for pristine MgH2 to 214 °C through the employment of Ti3CN. The desorbed MgH2 + 7.5 wt% Ti3CN can start absorption at room temperature, while the desorbed pristine MgH2 can only start absorption at 120 °C. The employment of Ti3CN can significantly improve the hydrogen release kinetics of MgH2, with the desorption activation energy decreasing from 121 to 80 kJ mol−1. Regarding thermodynamics, the desorption enthalpy changes of MgH2 and MgH2 + 7.5 wt% Ti3CN were 79.3 and 78.8 kJ mol−1, respectively. This indicates that the employment of Ti3CN does not alter the thermal stability of MgH2. Phase evolution studies through the use of X-ray diffraction and electron diffraction both confirm that Ti3CN remains stable during the hydrogen release and uptake process of the composite. This work will help understand the impact of a transition metal carbonitride on the hydrogen storage of MgH2.

High catalytic activity derived from TiNbAlC MAX towards improving the hydrogen storage properties of MgH2

MXenes are great catalysts for MgH2 hydrogen storage material. Nevertheless, the synthesis of MXenes needs a large quantity of corrosive HF solution to remove the Al layers from the MAX materials, which is harmful to the environment. In this work, TiNbAlC MAX was employed without HF-treatment to tailor the hydrogen storage of MgH2. The MgH2 + 10 wt% TiNbAlC composite was prepared by ball milling. The addition of 10 wt% TiNbAlC greatly reduces the onset temperature of MgH2 desorption from 332 °C to 197 °C. The composite can desorb 6.2 wt% of H2 in 10 min at a constant temperature of 300 °C. Moreover, the dehydrided MgH2 + 10 wt% TiNbAlC composite can start to absorb hydrogen at room temperature under a H2 pressure of 6 MPa. The hydrogen desorption activation energy of the composite was calculated by Kissinger’s method to be 101 kJ mol−1. Microstructures studies demonstrated that TiNbAlC will partially react with MgH2/H2 to form TiH1.971, which can act as a “hydrogen pump” to facilitate the hydrogen sorption of MgH2. This work suggests that MAX materials are good catalysts for hydrogen storage of MgH2 and provides new insight into the role of MAX phase in tailoring the hydrogen storage of Mg-based hydrogen storage materials.

Effect of LaCoO3 Synthesized via Solid-State Method on the Hydrogen Storage Properties of MgH2.

One of the ideal energy carriers for the future is hydrogen. It has a high energy density and is a source of clean energy. A crucial step in the development of the hydrogen economy is the safety and affordable storage of a large amount of hydrogen. Thus, owing to its large storage capacity, good reversibility, and low cost, Magnesium hydride (MgH2) was taken into consideration. Unfortunately, MgH2 has a high desorption temperature and slow ab/desorption kinetics. Using the ball milling technique, adding cobalt lanthanum oxide (LaCoO3) to MgH2 improves its hydrogen storage performance. The results show that adding 10 wt.% LaCoO3 relatively lowers the starting hydrogen release, compared with pure MgH2 and milled MgH2. On the other hand, faster ab/desorption after the introduction of 10 wt.% LaCoO3 could be observed when compared with milled MgH2 under the same circumstances. Besides this, the apparent activation energy for MgH2-10 wt.% LaCoO3 was greatly reduced when compared with that of milled MgH2. From the X-ray diffraction analysis, it could be shown that in-situ forms of MgO, CoO, and La2O3, produced from the reactions between MgH2 and LaCoO3, play a vital role in enhancing the properties of hydrogen storage of MgH2.

Ti3AlCN MAX for tailoring MgH2 hydrogen storage material: from performance to mechanism

Ti3AlCN MAX for tailoring MgH2 hydrogen storage material: from performance to mechanism

Combined “Gateway” and “Spillover” effects originated from a CeNi5 alloy catalyst for hydrogen storage of MgH2

Combined “Gateway” and “Spillover” effects originated from a CeNi5 alloy catalyst for hydrogen storage of MgH2

Interfacial engineering of nickel/vanadium based two-dimensional layered double hydroxide for solid-state hydrogen storage in MgH2

As a high-density solid-state hydrogen storage material, magnesium hydride (MgH2) is promising for hydrogen transportation and storage. Yet, its stable thermodynamics and sluggish kinetics are unfavorable for that required for commercial application. Herein, nickel/vanadium trioxide (Ni/V2O3) nanoparticles with heterostructures were successfully prepared via hydrogenating the NiV-based two-dimensional layered double hydroxide (NiV-LDH). MgH2 + 7 wt% Ni/V2O3 presented more superior hydrogen absorption and desorption performances than pure MgH2 and MgH2 + 7 wt% NiV-LDH. The initial discharging temperature of MgH2 was significantly reduced to 190 °C after adding 7 wt% Ni/V2O3, which was 22 and 128 °C lower than that of 7 wt% NiV-LDH modified MgH2 and additive-free MgH2, respectively. The completely dehydrogenated MgH2 + 7 wt% Ni/V2O3 charged 5.25 wt% H2 in 20 min at 125 °C, while the hydrogen absorption capacity of pure MgH2 only amounted to 4.82 wt% H2 at a higher temperature of 200 °C for a longer time of 60 min. Moreover, compared with MgH2 + 7 wt% NiV-LDH, MgH2 + 7 wt% Ni/V2O3 shows better cycling performance. The microstructure analysis indicated the heterostructural Ni/V2O3 nanoparticles were uniformly distributed. Mg2Ni/Mg2NiH4 and metallic V were formed in-situ during cycling, which synergistically tuned the hydrogen storage process in MgH2. Our work presents a facile interfacial engineering method to enhance the catalytic activity by constructing a heterostructure, which may provide the mentality of designing efficient catalysts for hydrogen storage.

Boosting the hydrogen storage performance of magnesium hydride with metal organic framework-derived Cobalt@Nickel oxide bimetallic catalyst

In this study, a MOF-derived bimetallic [email protected] catalyst was synthesized and doped into MgH2 to improve the hydrogen desorption and resorption kinetics. The [email protected] catalyst decreased the onset dehydrogenation temperature of MgH2 by 160 °C, compared with un-doped MgH2. The MgH2 + 9% (mass) [email protected] composite released 6.6% (mass) hydrogen in 350 s at 315 °C and uptook 5.4% (mass) hydrogen in 500 s at 165 °C, showing greatly accelerated de/rehydrogenation rates. Besides, the desorption activation energy of MgH2 + 9% (mass) [email protected] was decreased to (93.8 ± 8.4) kJ·mol−1. Noteworthy, symbiotic Mg2NiH4/Mg2CoH5 clusters were in-situ formed from bimetallic precursors and inlaid on MgH2 surface, which are considered as “multi-step hydrogen pumps”, and provides surface pathways for hydrogen absorption. Meanwhile, the introduced Mg2NiH4/Mg2CoH5 interfaces could provide numerous low energy barrier H diffusion channels, therefore accelerating the hydrogen release and uptake. This research proposes new insights to design high-efficiency bimetallic catalyst for MgH2 hydrogen storage.

A fancy hydrangea shape bimetallic Ni-Mo oxide of remarkable catalytic effect for hydrogen storage of MgH2

The design of catalysts with excellent catalytic activity plays an important role in the field of solid-state hydrogen storage of new energy sources. Herein, a novel hydrangea-like NiO@NiMoO4 composite catalyst was prepared through a facile hydrothermal reaction. Subsequently, NiO@NiMoO4 was doped into MgH2 by ball milling to solve the problems of high dehydrogenation temperature and slow desorption kinetics of MgH2. It can be seen from the experimental results that the MgH2 + 10 wt% NiO@NiMoO4 composite starts to dehydrogenate at about 190 °C, which is about 170 °C lower than that of pure MgH2. Meanwhile, after complete dehydrogenation, the composites can start to absorb hydrogen below 40 °C. Compared with pure MgH2, the activation energy of hydrogen absorption and dehydrogenation of the composite decreased by 47.6 kJ/mol and 46.5 kJ/mol, respectively. In 10th cycle tests, the MgH2 + 10 wt% NiO@NiMoO4 composite still has good cycle stability. After adding a small amount of biomass charcoal, the hydrogen storage capacity can even be maintained above 97%. Furthermore, the characterization results show that the in situ generated new species Mo and Mg2Ni/Mg2NiH4 synergistically promote the adsorption and dissociation of hydrogen. This new synergistic mechanism provides new comprehensive insights for improving reversible hydrogen storage in MgH2.

Revealing the effect of 2D carbides with different metal sites for improving hydrogen storage in MgH2.

Two-dimensional (2D) carbon materials are considered as efficient catalysts for improving hydrogen storage in MgH2, but their catalytic mechanisms of different materials remain unclear. Herein we compare the hydrogen storage properties of MgH2 with doping different 2D carbon materials for revealing their catalytic effecting mechanisms. It can be seen that the effect of 2D metal carbides including Nb2C and Ti2C are superior to 2D graphene for improving hydrogen storage properties of MgH2, where the Ti2C exhibits the best catalytic effect with a remarkable decrease of activation energy (E a) from ∼124 kJ/mol for doping graphene to ∼86 kJ/mol. This is related to the changes of individual metal and graphite chemical valence states of catalysts. The high catalytic activity of the hydrogen storage reaction originates from its unique layered structure and in situ formation of MHX, i.e., the tiny metal crystals can serve as a channel to facilitate hydrogen transport in MgH2 matrix. Moreover, the Ti catalytic effect is better than Nb, which originates from the surface of the multivalent Ti atoms is an intermediate of the electron moving between H− and Mg2+, thus leading to the Ti2C catalyzed MgH2 with superior hydrogen kinetic and cyclic performance.

Remarkable kinetics of novel Ni@CeO2–MgH2 hydrogen storage composite

Magnesium hydroxide (MgH2) has excellent reversibility and high capacity, and is one of the most promising materials for hydrogen storage in practical applications. However, it suffers from high dehydrogenation temperature and slow sorption kinetics. Rare earth hydrides and transition metals can both significantly improve the de/hydrogenation kinetics of MgH2. In this work, MgH2–Mg2NiH4–CeH2.73 is in-situ synthesized by introducing Ni@CeO2 into MgH2. The unique coating structure of Ni@CeO2 facilitates homogeneous distribution of synergetic CeH2.73 and Mg2NiH4 catalytic sites in subsequent ball milling process. The as-fabricated composite MgH2-10 wt% Ni@CeO2 powders possess superior hydrogenation/dehydrogenation characteristics, absorbing 4.1 wt% hydrogen within 60 min at 100 °C and releasing 5.44 wt% H2 within 10 min at 350 °C. The apparent activation energy of MgH2-10 wt% Ni@CeO2 is determined to be 84.8 kJ/mol and it has favorable hydrogen cycling stability with almost no decay in capacity after 10 cycles.

Striking enhanced effect of PrF3 particles on Ti3C2 MXene for hydrogen storage properties of MgH2

The enhanced effect of metal catalysts is crucial to achieve advanced performance of hydrogen storage system. Rational design of catalysts with superior catalytic activity is significant to regulate the re-/hydrogenation kinetics of MgH2. Herein, Ti3C2-supported praseodymium(III) fluoride (PrF3) nanoparticles (PrF3/Ti3C2) composite was prepared by hydrothermal method, which exhibited superior catalytic activity toward hydrogen storage of MgH2. The onset temperature of dehydrogenation was reduced to 180 °C after adding 5 wt% PrF3/Ti3C2, corresponding to a reduction of 107 °C compared with pristine MgH2. About 7.0 wt% hydrogen was rapidly desorbed within 3 min at 260 °C and 6.6 wt% hydrogen was absorbed within 36 s at 200 °C for MgH2-5 wt% PrF3/Ti3C2. Moreover, MgH2-5 wt% PrF3/Ti3C2 exhibited an excellent capacity retention of 92.5% even after 10 cycles. Experimental results reveal that the electron transfer among Ti-species (Ti0, Ti2+, and Ti3+) occurred due to the striking enhanced effect of PrF3 on Ti3C2 MXene during the reaction process, and the synergistic action between Ti-species and PrF3 are responsible for the markedly enhanced hydrogen storage properties of MgH2. This study is helpful to the design and optimization of hydrogen storage materials for mobile application.

Achieve high-efficiency hydrogen storage of MgH2 catalyzed by nanosheets CoMoO4 and rGO

The development of high-efficiency carbon-based multifunctional catalysts is of great significance for improving solid-state hydrogen storage materials . Herein, it was confirmed that CoMoO 4 sheet-like nanocatalysts uniformly supported on the surface of reduced graphene oxide (CoMoO 4 /rGO) were successfully prepared by a simple hydrothermal reaction . The novel CoMoO 4 /rGO catalyst was subsequently doped into MgH 2 to improve its hydrogen storage performance. MgH 2 –10 wt% CoMoO 4 /rGO starts to release hydrogen at around 204 °C, which is about 36 °C and 156 °C lower than that of MgH 2 −10 wt%CoMoO 4 and pure MgH 2 , respectively. In addition, 6.25 wt% H 2 can be released within 10 min at 300 °C. After complete dehydrogenation , H 2 can be absorbed below 80 °C. Meanwhile, it can absorb 4.2 wt% H 2 in 20 min under the condition of 150 °C and 3 MPa. Moreover, the activation energy of hydrogen absorption and dehydrogenation of MgH 2 –10 wt%CoMoO 4 /rGO composites are reduced by 31.44 kJ mol −1 and 33.78 kJ mol −1 , respectively, compared with pure MgH 2 . Cycling experiment shows that the MgH 2 –10 wt%CoMoO 4 /rGO composite system can still maintain about 98% of the hydrogen storage capacity after 10 cycles. Furthermore, studies on the catalytic mechanism show that the synergistic effect between the in-situ generated MgO, Co 7 Mo 6 and Mo may help to promote the diffusion of H 2 , thereby improving the MgH 2 Hydrogen storage properties. • MgH 2 –10 wt%CoMoO 4 /rGO composite system was reported for the first time. • MgH 2 –10 wt%CoMoO 4 /rGO composite material starts dehydrogenation at about 204 °C. • MgH 2 –CoMoO 4 /rGO composites showed promising kinetic properties. • MgH 2 –CoMoO 4 /rGO composites showed good cyclic stability. • MgO, Mo and Co 7 Mo 6 were formed in situ during the reaction.

In situ formation of multiple catalysts for enhancing the hydrogen storage of MgH2 by adding porous Ni3ZnC0.7/Ni loaded carbon nanotubes microspheres

MgH2 is considered one of the most promising hydrogen storage materials because of its safety, high efficiency, high hydrogen storage quantity and low cost characteristics. But some shortcomings are still existed: high operating temperature and poor hydrogen absorption dynamics, which limit its application. Porous Ni3ZnC0.7/Ni loaded carbon nanotubes microspheres (NZC/Ni@CNT) is prepared by facile filtration and calcination method. Then the different amount of NZC/Ni@CNT (2.5, 5.0 and 7.5 wt%) is added to the MgH2 by ball milling. Among the three samples with different amount of NZC/Ni@CNT (2.5, 5.0 and 7.5 wt%), the MgH2-5 wt% NZC/Ni@CNT composite exhibits the best hydrogen storage performances. After testing, the MgH2-5 wt% NZC/Ni@CNT begins to release hydrogen at around 110 °C and hydrogen absorption capacity reaches 2.34 wt% H2 at 80 °C within 60 min. Moreover, the composite can release about 5.36 wt% H2 at 300 °C. In addition, hydrogen absorption and desorption activation energies of the MgH2-5 wt% NZC/Ni@CNT composite are reduced to 37.28 and 84.22 KJ/mol H2, respectively. The in situ generated Mg2NiH4/Mg2Ni can serve as a "hydrogen pump" that plays the main role in providing more activation sites and hydrogen diffusion channels which promotes H2 dissociation during hydrogen absorption process. In addition, the evenly dispersed Zn and MgZn2 in Mg and MgH2 could provide sites for Mg/MgH2 nucleation and hydrogen diffusion channel. This attempt clearly proved that the bimetallic carbide Ni3ZnC0.7 is a effective additive for the hydrogen storage performances modification of MgH2, and the facile synthesis of the Ni3ZnC0.7/Ni@CNT can provide directions of better designing high performance carbide catalysts for improving MgH2.

Regulation of Kinetic Properties of Chemical Hydrogen Absorption and Desorption by Cubic K2MoO4 on Magnesium Hydride.

Transition metal catalysts are particularly effective in improving the kinetics of the reversible hydrogen storage reaction for light metal hydrides. Herein, K2MoO4 microrods were prepared using a simple evaporative crystallization method, and it was confirmed that the kinetic properties of magnesium hydride could be adjusted by doping cubic K2MoO4 into MgH2. Its unique cubic structure forms new species in the process of hydrogen absorption and desorption, which shows excellent catalytic activity in the process of hydrogen storage in MgH2. The dissociation and adsorption time of hydrogen is related to the amount of K2MoO4. Generally speaking, the more K2MoO4, the faster the kinetic performance and the shorter the time used. According to the experimental results, the initial dehydrogenation temperature of MgH2 + 10 wt% K2MoO4 composite is 250 °C, which is about 110 °C lower than that of As-received MgH2. At 320 °C, almost all dehydrogenation was completed within 11 min. In the temperature rise hydrogen absorption test, the composite system can start to absorb hydrogen at about 70 °C. At 200 °C and 3 MPa hydrogen pressure, 5.5 wt% H2 can be absorbed within 20 min. In addition, the activation energy of hydrogen absorption and dehydrogenation of the composite system decreased by 14.8 kJ/mol and 26.54 kJ/mol, respectively, compared to pure MgH2. In the cycle-stability test of the composite system, the hydrogen storage capacity of MgH2 can still reach more than 92% after the end of the 10th cycle, and the hydrogen storage capacity only decreases by about 0.49 wt%. The synergistic effect among the new species MgO, MgMo2O7, and KH generated in situ during the reaction may help to enhance the absorption and dissociation of H2 on the Mg/MgH2 surface and improve the kinetics of MgH2 for absorption and dehydrogenation.

Constructing graphene nanosheet-supported FeOOH nanodots for hydrogen storage of MgH2

Constructing graphene nanosheet-supported FeOOH nanodots for hydrogen storage of MgH2

Modified MgH2 Hydrogen Storage Properties Based on Grapefruit Peel-Derived Biochar

Carbon materials play an important role in the development of solid hydrogen storage materials. The main purpose of this work is to study the low-cost synthesis of biomass carbon (BC) and its positive effect on the hydrogen storage behavior of magnesium hydride (MgH2). Herein, it is proven that when biomass carbon (BC) is used together with magnesium hydride (MgH2), biomass carbon can be used as an adsorption and desorption channel for hydrogen. The initial dehydrogenation temperature of MgH2 + 10 wt% BC composite is 250 °C, which is 110 °C lower than that of pure MgH2. In addition, the MgH2 + 10 wt% BC composite system can complete all dehydrogenation processes within 10 min at 350 °C. Meanwhile, 5.1 wt% H2 can also be dehydrogenated within 1 h at 300 °C. Under the same conditions, MgH2 hardly starts to release hydrogen. After complete dehydrogenation, the composite can start to absorb hydrogen at 110 °C. Under the conditions of 225 °C and 3 MPa, 6.13 wt% H2 can be absorbed within 1 h, basically reaching the theoretical dehydrogenation limit. Cycling experiments show that the MgH2 + 10 wt% BC composite has a good stability. After 10 cycles, the hydrogen storage capacity shows almost no obvious decline. It is believed that this study can help in the research and development of efficient carbon-based multifunctional catalysts.

Ultrafast hydrogenation of magnesium enabled by tetragonal ZrO2 hierarchical nanoparticles

Transition metal catalysts are particularly effective in improving the reaction kinetics of light metal hydrides for reversible hydrogen storage. Herein, tetragonal ZrO2 hierarchical nanoparticles (nano-ZrO2) composed of primary particles of ∼4 nm in diameter are successfully synthesized by a facile one-pot solvothermal process. The unique hierarchical structure features homogeneous distributions of in situ formed multivalent Zr-based species, which allow superior catalytic activity for hydrogen storage in MgH2. The MgH2+10 wt% nano-ZrO2 starts releasing H2 at 163 °C after one activation, which is 107 °C lower than additive-free MgH2, and 50 °C lower than that of bulk ZrO2-doped MgH2. At 230 °C, 5.9 wt% of H is rapidly liberated within 20 min from the nano-ZrO2-containing MgH2. More importantly, the material shows superior hydrogenation kinetics compared with all reported catalyst-modified MgH2. The nano-ZrO2-containing Mg took up 4.0 wt% of H in only 12 s at 100 °C under 50 bar H2, 400 times faster than the bulk-ZrO2-modified sample. Even at 50 °C, approximately 1.8 wt% H was absorbed within 1 min. Our findings provide useful insights into the design and development of high-performance catalysts toward solid-state hydrogen storage materials.

A Unique Nanoflake‐Shape Bimetallic Ti–Nb Oxide of Superior Catalytic Effect for Hydrogen Storage of MgH2

MgH2 is one of the most promising solid hydrogen storage materials due to its high capacity, excellent reversibility, and low cost. However, its operation temperature needs to be greatly reduced to realize its practical applications, especially in the highly desired fuel cell fields. This work synthesizes a 2D nanoflake-shape bimetallic Ti-Nb oxide of TiNb2 O7 , which has high surface area and shows superior catalytic effect for the hydrogen storage of MgH2 . Incorporated with the TiNb2 O7 nanoflakes as low as 3 wt%, MgH2 shows a low onset dehydrogenation temperature of 178 °C, which is lowered by 100 °C compared with the pristine one. A dehydrogenation capacity as high as 7.0 wt% H2 is achieved upon heating to 300 °C. The capacity retention is as high as 96% after 30 cycles. The mechanism of the improved hydrogen storage properties is analyzed by density functional theory (DFT) calculation and the microstructural evolution during dehydrogenation and hydrogenation. This work provides an MgH2 system with high available capacity and low operation temperature by a unique structural design of the catalyst. The high surface area feature of the TiNb2 O7 nanoflakes and the synthesis method hopefully can develop the application of TiNb2 O7 .