Hydrogen Decomposition Research Articles

Interfacial Engineering of Polymer Membranes with Intrinsic Microporosity for Dendrite-Free Zinc Metal Batteries.

Metallic zinc has emerged as a promising anode material for high-energy battery systems due to its high theoretical capacity (820 mAh g-1), low redox potential for two-electron reactions, cost-effectiveness and inherent safety. However, current zinc metal batteries face challenges in low coulombic efficiency and limited longevity due to uncontrollable dendrite growth, the corrosive hydrogen evolution reaction (HER) and decomposition of the aqueous ZnSO4 electrolyte. Here, we report an interfacial-engineering approach to mitigate dendrite growth and reduce corrosive reactions through the design of ultrathin selective membranes coated on the zinc anodes. The submicron-thick membranes derived from polymers of intrinsic microporosity (PIMs), featuring pores with tunable interconnectivity, facilitate regulated transport of Zn2+-ions, thereby promoting a uniform plating/stripping process. Benefiting from the protection by PIM membranes, zinc symmetric cells deliver a stable cycling performance over 1500 h at 1 mA/cm2 with a capacity of 0.5 mAh while full cells with NaMnO2 cathode operate stably at 1 A g-1 over 300 cycles without capacity decay. Our work represents a new strategy of preparing multi-functional membranes that can advance the development of safe and stable zinc metal batteries.

Interfacial Engineering of Polymer Membranes with Intrinsic Microporosity for Dendrite‐free Zinc Metal Batteries

Metallic zinc has emerged as a promising anode material for high‐energy battery systems due to its high theoretical capacity (820 mA h g‐1), low redox potential for two‐electron reactions, cost‐effectiveness and inherent safety. However, current zinc metal batteries face challenges in low coulombic efficiency and limited longevity due to uncontrollable dendrite growth, the corrosive hydrogen evolution reaction (HER) and decomposition of the aqueous ZnSO4 electrolyte. Here, we report an interfacial‐engineering approach to mitigate dendrite growth and reduce corrosive reactions through the design of ultrathin selective membranes coated on the zinc anodes. The submicron‐thick membranes derived from polymers of intrinsic microporosity (PIMs), featuring pores with tunable interconnectivity, facilitate regulated transport of Zn2+‐ions, thereby promoting a uniform plating/stripping process. Benefiting from the protection by PIM membranes, zinc symmetric cells deliver a stable cycling performance over 1500 h at 1 mA/cm² with a capacity of 0.5 mAh while full cells with NaMnO2 cathode operate stably at 1 A g‐1 over 300 cycles without capacity decay. Our work represents a new strategy of preparing multi‐functional membranes that can advance the development of safe and stable zinc metal batteries.

In situ construction of the W18O49/Mn0.45Cd0.55S S-scheme heterojunction for enhanced photocatalytic hydrogen generation

Rapid compounding of semiconductor carriers is a crucial element limiting the performance of semiconductor photocatalytic decomposition of aqueous hydrogen, and the rational design of heterojunction is one effective method to improve the performance. In this paper, W18O49/Mn0.45Cd0.55S composite materials were prepared by basic hydrothermal and solvent-thermal strategy, additionally, S-scheme heterojunction was constructed between W18O49 and Mn0.45Cd0.55S by the analysis of the energy band structure. Furthermore, the W18O49/Mn0.45Cd0.55S-10 has excellent achievement and stability, and the photocatalytic production of hydrogen under visible light can reach up to 32.47 mmol g−1 h−1, which is 2.9 folds higher than Mn0.45Cd0.55S. The apparent quantum efficiencies (AQE) of Mn0.45Cd0.55S and W18O49/Mn0.45Cd0.55S-10 were 9.2 % and 16.5 %, respectively. The S-scheme heterojunction effectively ameliorates the space charge separation for W18O49 and Mn0.45Cd0.55S. This work may prove to be instructive for synthesizing remarkable performing S-scheme heterojunction photocatalysts.

Neural network potential-based molecular investigation of pollutant formation of ammonia and ammonia-hydrogen combustion

This study developed neural network potentials (NNPs) specifically designed for ammonia and ammonia-hydrogen combustion systems for the first time. The NNPs were employed to perform reactive molecular dynamics (RMD) simulations, combining the precision of density functional theory (DFT) calculations with the efficiency of empirical force fields. NNP-based RMD simulations provide a more detailed and comprehensive understanding of chemical reaction mechanisms. The impacts of different equivalence ratios and hydrogen addition on ammonia combustion as well as NOX and N2O formation were analysed. The results indicate that both the addition of hydrogen and the reduction of equivalence ratios contribute to enhancing ammonia combustion. The primary reason is the enhancement of the oxidative environment within the system, leading to a significant increase in the frequency of reactions associated with oxidising radicals such as OH, O, and HO2. This is also the cause for the increased production of NO and NO2, because the formation of NO depends on the oxidation of NH and NH2, while NO2 is formed through the oxidation of NO. An interesting finding is that the addition of hydrogen decelerates the generation of N2O, while reducing the equivalence ratio promotes N2O production. This phenomenon is attributed to the additional H radicals generated during hydrogen decomposition, which hinders the binding between NH and NO, resulting in a reduction in the formation of the precursor HN2O required for N2O formation.

Simultaneous Piezoelectrocatalytic Hydrogen-Evolution and Degradation of Water Pollutants By Quartz Microrods@Few-Layered MoS2 Hierarchical Heterostructures

Intense light attenuation in water/wastewater results in photocatalysts exhibiting a low quantum efficiency. This study develops a novel piezoelectrocatalysis system, which involves quartz microrods (MRs) abundantly decorated with active edge-sites MoS2 nanosheets to form quartz microrods@few-layered MoS2 hierarchical heterostructure (QMSH). Through theoretical calculations, quartz MR serves as a parallel-plate capacitor, which is self-powered to provide an internal electric field to the few-layered MoS2 nanosheets surrounding the quartz MR surfaces, and the piezoelectric potential (piezopotential) effectively facilitates redox reactions with the free carrier in MoS2. The self-powered quartz MRs in QMSH present an internal bias to the MoS2 nanosheets, thus yielding a piezoelectrocatalysis system. An efficient piezoelectrocatalytic hydrogen evolution reaction (HER) and decomposition of wastewater without light irradiation could achieve simultaneously. The second-order rate constant of QMSH is approximately 0.631 L mg-1min-1, which was 650-fold that of quartz MRs, indicating that the piezoelectric heterostructural catalysts display exceptionally high efficiency on piezo-electrocatalytic redox reactions rather than in the peizocatalytic process. The H2-production rate of QMSH catalysts approached approximately 6456 μmo1·g−1 h−1 and peaked at approximately 16.8 mmol g−1 in 8 h. The piezoelectrocatalytic process may be a promising method for treating industrial wastewater and producing clean energy.

Ternary heterostructure Cu-ZnIn2S4/WO3/WS2 flower-like microspheres for highly-efficient photocatalytic hydrogen evolution under visible-light irradiation

Developing a new composite photocatalyst is the key to achieving efficient photocatalytic decomposition of aquatic hydrogen. In this study, Cu-ZnIn2S4/WO3/WS2 nanostructures were prepared by a two-step hydrothermal method. The unique charge transfer mechanism of Cu-doped and mixed heterojunctions (Z-scheme heterojunctions and Type-I heterojunctions) significantly enhances charge transfer and separation, resulting in excellent photocatalytic hydrogen evolution performance of Cu-ZnIn2S4/WO3/WS2. The hydrogen evolution rate of Cu-ZnIn2S4/WO3/WS2 is 93032.29 µmol·g−1·h−1, 37.82 and 3.33 times that of ZnIn2S4 and Cu-ZnIn2S4, respectively, and the quantum efficiency at 430nm is 37.04 %. It is also superior to Pt-modified Cu-ZnIn2S4 (71654.39 µmol·g−1·h−1) and most reported ZnIn2S4-based photocatalysts. In addition, the density functional theory (DFT) calculation results further show that the absolute value of ΔGH* of the composite photocatalyst is significantly reduced to 0.08 eV, and the adsorption–desorption potential barrier is reduced considerably, indicating that the Cu-ZnIn2S4/WO3/WS2 photocatalytic system is more favorable to H* adsorption. This excellent performance is attributed to the unique transfer mechanism of Cu doping and mixed heterojunctions. This study provides a new idea for photocatalytic hydrogen production and can provide a valuable reference for future research on photocatalytic hydrogen production technology.

Robust and Highly Efficient Electrochemical Hydrogen Production from Hydrazine-Assisted Water Electrolysis Enabled by the Metal-Support Interaction of Ru/C Composites.

Hydrazine oxidation-assisted water electrolysis provides a promising way for the energy-efficient electrochemical hydrogen (H2) and synchronous decomposition of hydrazine-rich wastewater, but the development of highly active catalysts still remains a great challenge. Here, we demonstrate the robust and highly active Ru nanoparticles supported on the hollow N-doped carbon microtube (denoted as Ru NPs/H-NCMT) composite structure as HER and HzOR bifunctional electrocatalysts. Thanks to such unique hierarchical architectures, the as-synthesized Ru NPs/H-NCMTs exhibit prominent electrocatalytic activity in the alkaline condition, which needs a low overpotential of 29 mV at 10 mA cm-2 for HER and an ultrasmall working potential of -0.06 V (vs RHE) to attain the same current density for HzOR. In addition, assembling a two-electrode hybrid electrolyzer using as-prepared Ru NPs/H-NCMT catalysts shows a small cell voltage of mere 0.108 V at 100 mA cm-2, as well as the remarkable long-term stability. Density functional theory calculations further reveal that the Ru NPs serve as the active sites for both the HER and HzOR in the nanocomposite, which facilitates the adsorption of H atoms and hydrazine dehydrogenation kinetics, thus enhancing the performances of HER and HzOR. This work paves a novel avenue to develop efficient and stable electrocatalysts toward HER and HzOR that promises energy-saving hybrid water electrolysis electrochemical H2 production.

Logic-Gates of Gas Pressure for Portable, Intelligent and Multiple Analysis of Metal Ions.

DNA logic gates have shown outstanding magic in intelligent biology applications, but it remains challenging to construct a portable, affordable and convenient DNA logic gate. Herein, logic gates of gas pressure were innovatively developed for multiplex analysis of metal ions. Hg2+ and Ag+ were input to interact specifically with the respective mismatched base pairs, which activated DNA extension reaction by polymerase and led to the enrichment of platinum nanoparticles for catalyzing the decomposition of peroxide hydrogen. Thus, the gas pressure obtained from a sealed well was used as output for detecting or identifying metal ions. Hg2+ and Ag+ were sensitively and selectively detected, and the assay of the real samples was also satisfactory. Based on this, DNA logic gates, including YES, NOT, AND, OR, NAND, NOR, INHIBIT, and XOR were successfully established using a portable and hand-held gas pressure meter as detector. So, the interactions between DNA and metal ions were intelligently transferred into the output of gas pressure, which made metal ions to be detected portably and identified intelligently. Given the remarkable merits of simplicity, logic operation, and portable output, the metal ion-driven DNA logic gate of gas pressure provides a promising way for intelligent and portable biosensing.

Nickel-iron catalyst for decomposition of methane to hydrogen and filamentous carbon: Effect of calcination and reaction temperatures

Nickel-ferrite Ni-Fe (molar ratio 1:2) were synthesised and calcined at different temperatures. The catalytic performances of Ni-Fe for methane decomposition and production of hydrogen and carbon nanostructures were evaluated at various calcination (350–800 °C) and reaction temperatures (700–800 °C). Fresh and spent catalysts were characterized using scanning electron microscopy (SEM), BET surface area, X-ray diffraction (XRD), TGA and Raman spectroscopy. XRD results revealed the formation of highly crystalline NiFe2O4 in calcined samples, while Ni-Fe alloys were observed in the spent catalysts. The NiFe2O4 catalyst has a mesoporous structure with monomodal pore distribution. The surface area decreased from 107.0 to 3.8 m2/g with increasing calcination temperature from 350 to 800 °C. Methane conversion, 48.50%, and hydrogen formation rate, 97.70 × 10-5 mol H2 g−1 min−1 was obtained at reaction temperature of 800 °C. The catalyst activity slightly improved by increasing calcination temperature. The SEM images of spent catalysts revealed the formation of some filamentous carbon over all spent catalysts except for that operated at reaction temperature of 700 °C. TGA studies revealed that the deposited carbon increased with increase in reaction and calcination temperatures and achieved 42.50 and 59.32 wt%, respectively. The graphitization and crystalline of the deposited carbon slightly decreases as calcination temperature increased.

ß-Ga2O3 flake based Schottky diode hydrogen sensor

2D (2-dimensional) (100) plane β phase Ga2O3 (β-Ga2O3) flake based Pt Schottky diode is demonstrated for hydrogen sensing application. The (100) plane β-Ga2O3 flake was formed from the side wall of a mother (2̅01) plane β-Ga2O3 bulk substrate by the cost-effective mechanical exfoliation method. The hydrogen response of the (100) plane Ga2O3 flake based diode with the catalytic Pt Schottky electrode for hydrogen decomposition reaction was measured in the wide concentration range of 50–40,000 ppm hydrogen. The β-Ga2O3 flake based hydrogen sensor showed excellent responsivity of 2.32 × 108% for the 500 ppm hydrogen exposure at 25°C, and exhibited a reliable hydrogen sensing behavior up to 400°C. The decent cross-selectivity of the (100) plane β-Ga2O3 flake based Pt Schottky diode sensor over the other gases including N2, CO, CO2, CH4, NO2, NH3, and O2 was observed. In addition, the effect of the humidity on hydrogen sensing was investigated.

Highly dispersed CuO nanoparticle on ZIF-4 framework as anode material for LIBs

A novel prepared ZIF-4@CuO is proposed as lithium-ion battery (LIB) anode material in this work. ZIF-4-CuCl 2 is prepared by the hydrogen extraction reaction in which CuCl 2 replaced the hydrogen sites on the imidazole-based N-heterocyclic carbene of ZIF-4 for under basic conditions. ZIF-4@CuO was prepared by decomposition of ZIF-4-CuCl 2 precursor. The formed CuO was isolated and highly dispersed by the ZIF-4 frame. The combination of porous structure by ZIF and highly dispersed CuO nanoparticles strongly promotes the reaction kinetics of the electrode. The reversible specific capacity of ZIF-4@CuO anode material is 425 mA h g -1 at 1000 mA g -1 after 300 cycles, exhibits excellent electrochemical performance in LIBs. The preparation of highly dispersed nanoparticles explores a novel strategy for the anodes design of LIBs with superior performance. • CuO nanoparticles are highly dispersed on the ZIF-4 framework by hydrogen extraction reaction and decomposition reaction. • The porous structure by ZIF-4 and highly dispersed CuO nanoparticles synergistically enhance the electrochemical performance. • The ZIF-4@CuO electrode still maintains the capacity of 819 mA h g -1 after 100 cycles at current densities of 100 mA g -1 .

A new numerical simulation method of hydrogen and carbon compounds in shale reservoir

Hydrogen energy can be produced by the decomposition of hydrogen and carbon compounds. A numerical analysis method of accuracy and efficiency provides important reference value for optimizing development plans and predicting production performance of hydrogen and carbon compounds. In this work, embedded discrete fracture model (EDFM) is used to study the production performance of hydrogen and carbon compounds under non-liner seepage under the threshold pressure gradient and complex fracture systems consist of the hydraulic fractures, secondary fractures, natural fractures. A dual-permeability model of the same case is also constructed as a comparison study to analyze the development of hydrogen and carbon compounds. On this basis, the influence of threshold pressure gradient on production of hydrogen and carbon compounds is quantitatively evaluated in this paper to modify the numerical model and a novel method for the simulation of fractured hydrogen and carbon compounds reservoirs is provided. Through model comparison, the impact of fractures in the reservoir on production can reach 289.1%. A dual-permeability model of the same case is also constructed as a comparison study to analyze the development of the reservoir and the result shows a 7.9% distinction on the cumulative production. It is analyzed that when the threshold pressure gradient is increased from 0.1 MPa/m to 0.6 MPa/m, the output decline of different models ranges from 6% to 15% and a novel method improving model fidelity for the simulation of fracture reservoirs is provided.

Physical properties of LiXH4 (X= B, Al) hydrogen storage materials: ab-initio study

The mechanical and thermodynamical features of LiBH4 and LiAlH4 complex hydrides in the α, β and γ phases are evaluated using density functional theory. To our knowledge, thermal parameters such as, the Grüneisen parameter γ, the heat capacity, and thermal expansion coefficient of LiXH4 (X = B, Al) complex hydrides in α, β and γ phases are computed for the first time. The parameters are determined in terms of pressure (0–6 GPa) and temperature (0–600) K using the quasi-harmonic Debye model. The computed stress–strain relationships effectively yield the elastic constants of a single crystal. The estimated elastic constants of α-LiBH4 compound are noticeably higher than those of several closely similar ABH4 (A = Na, K, Rb, and Cs) borohydrides. In the β-LiAlH4 tetragonal structure, the [001] direction is readily compressible as compared to the [100] direction. The compressibility modulus of the LiBH4 compound is greater than that of the LiAlH4. However, the distance between B and H is less than the distance between Al and H. This might be explained by the presence of covalent bonds in BH4 and AlH4 in LiXH4 (X = B, Al). The melting temperatures of LiXH4 (X = B, Al) are used to predict the temperatures of hydrogen decomposition. The obtained melting temperature of α-LiBH4 is higher than that of β-LiAlH4. Thus, LiAlH4's decomposition temperature at which hydrogen is emitted from a fuel cell is anticipated to be lower than that of the LiBH4 compound. The bonding behavior of α-LiBH4 is more directed than that of β-LiAlH4. All the LiXH4 (X = B, Al) are found to be ductile except α-LiAlH4 which is found to be fragile. LiBH4 experiences greater volume change during uniaxial deformation than LiAlH4 and both are centrally strong solids. Our PBE calculations yield the linear compressibility and Young's modulus orientation dependent. The orthorhombic LiBH4 and tetragonal LiAlH4 are isotropic in bulk and anisotropic in Young's modulus.

Super Material Borophene: Next Generation of Graphene

We talked about how the new wonder material borophene is stronger and more flexible than graphene in this research. It’s an excellent conductor of both electricity and heat, as well as a one-of-a-kind superconductor. The orientation of the material and the arrangement of vacancies affect these properties. Borophene is also rather light and reactive. Graphene was the wonderful new wonder material not long ago. Tubes, balls and other strange shapes can be formed from a super-strong, atom-thick sheet of carbon. The idea of a new age of graphene-based computer processing and a rich graphene chip industry has been highlighted by materials scientists. However, the remarkable qualities of borophene have lately astonished everyone. It has optimum strength and in-plane flexibility. In some combinations, they can be stronger and more flexible than graphene. Borophene’s high theoretical specific capacities, electrical conductivity and ion transport capabilities make it a promising anode material for batteries. Borophene has a wide range of possible applications due to its unusual physical and chemical features. It is capable of accelerating the decomposition of hydrogen and oxygen, is lightweight and can act as a reactant. We describe the work on borophene in this review, with a focus on current developments. The phases of borophene are first introduced through experimental synthesis and theoretical predictions. The physical and chemical qualities are then summarized, including mechanical, thermal, electrical, optical and superconducting properties.

Experimental evidence for the suitability of the hydrogen decomposition process for the recycling of Nd-Fe-B sintered magnets

An effective and complete processing route for the recycling of sintered Nd-Fe-B scrap magnets was proposed. Sintered Nd-Fe-B magnets were subjected to the Hydrogen Decrepitation (HD) process at various temperatures in the range of 50–300 °C, at two different pressures, 50 kPa and 200 kPa, followed by vacuum dehydrogenation in the range of 720–820 °C. The structure refinement efficiency and magnetic properties of the powders obtained were characterized. Low hydrogen pressure (50 kPa) was found to increase the magnetic properties at each temperature for all powder fractions. It was also shown that particle refinement occurs at low (50 °C, 100 °C) temperatures for low (50 kPa) pressure and higher temperatures (200 °C, 300 °C) for high pressure (200 kPa), respectively. High pressure also accelerates the initialization of the HD process at each temperature. No correlation was found between hydrogenation temperature and magnetic properties of the powders, except for the small increase in coercivity increase with growing temperature. The coarse fraction (400–500 µm) was found to have the highest magnetic properties for almost each HD process. The best magnetic properties Hci = 497 kA/m, Br = 1.1 T, and (BH)max = 121 kJ/m3 were obtained for hydrogenation at a temperature of 50 °C, pressure 50 kPa and dehydrogenation at 780 °C.

Non-Adiabatic Reaction Dynamics in the Gas-Phase Formation of Phosphinidenesilylene, the Isovalent Counterpart of Hydrogen Isocyanide, under Single-Collision Conditions.

The phosphinidenesilylene (HPSi; X1A') molecule was prepared via a directed gas-phase synthesis in the bimolecular reaction of ground-state atomic silicon (Si; 3P) with phosphine (PH3; X1A1) under single-collision conditions. The chemical dynamics are initiated on the triplet surface via addition of a silicon atom to the non-bonding electron pair of phosphine, followed by non-adiabatic dynamics and surface hopping to the singlet manifold, accompanied by isomerization via atomic hydrogen shift and decomposition to phosphinidenesilylene (HPSi, X1A') along with molecular hydrogen. Statistical calculations predict that silylidynephosphine (HSiP, X1Σ+) is also formed, albeit with lower yields. The barrier-less route to phosphinidenesilylene opens up a multipurpose mechanism to access the hitherto obscure class of phosphasilenylidenes through silicon-phosphorus coupling via reactions of atomic silicon with alkylphosphines under single-collision conditions in the absence of successive reactions of the reaction products, which are not feasible to prepare by traditional synthetic routes.

Potential effective inhibitory compounds against Prostate Specific Membrane Antigen (PSMA): A molecular docking and molecular dynamics study

One of the most prevalent cancers in men is prostate cancer and could be managed with immunotoxins or antibody treatment. Because of the substantial rise of the Prostate-Specific Antigen and the Prostate-Specific Membrane Antigen (PSMA), cancer vaccination should be rendered with these antigens. Through pharmacodynamic experiments in a library of natural compounds from ZINC database, the current research sought to identify compounds that could suppress PSMA protein. To test the most productive compounds for further research, the Library has been scanned with Pharmacophore and ADMET analysis followed by molecular docking methods in the first phase. After selecting 15 ligands with the best pose related to docking results, to evaluate the stability of the ligand-protein bounds of the compounds, a molecular dynamics simulation considering the effect of the presence of zinc ions on the protein structure was performed. The measurement of ligand binding modes and free energy has shown that four compounds, including Z10, Z06, Z01, and Z03, have formed critical interactions with the active site's residues. Besides, multiple approaches were employed to determine their inhibition rating and describe the variables that facilitate the attachment of ligands to the protein active site. The results are obtained from the MMPBSA/GBSA analysis of four selected small molecules (Z10, Z06, Z01, and Z03), which are very close to the IC50 value of reference ligand (DCIBzl); they are −13.85 kcal/mol, −12.58 kcal/mol, −10.71 kcal/mol and −9.39 kcal/mol respectively. Finally, we evaluate the results obtained from selected ligands using hydrogen bond and decomposition analyzes. We have examined the effective interactions between ligands and S1/S1ˊpockets in protein. Our computational results illustrate the design of more efficient inhibitors of PSMA.

Mechanistic in situ insights into the formation, structural and catalytic aspects of the La2NiO4 intermediate phase in the dry reforming of methane over Ni-based perovskite catalysts

We focus on the stability and bulk/surface structural properties of the Ruddlesden-Popper phase La2NiO4 and their consequences for dry reforming of methane (DRM) activity. Fuelled by the appearance as a crucial intermediate during in situ decomposition of highly DRM-active LaNiO3 perovskite structures, we show that La2NiO4 can be equally in situ decomposed into a Ni/La2O3 phase offering CO2 capture and release necessary for DRM activity, albeit at much higher temperatures compared to LaNiO3. Decomposition in hydrogen also leads to an active Ni/La2O3 phase. In situ X-ray diffraction during DRM operation reveals considerable coking and encapsulation of exsolved Ni, yielding much smaller Ni crystallites compared to on LaNiO3, where coking is virtually absent. Generalizing the importance of intermediate Ruddlesden-Popper phases, the in situ decomposition of La-based perovskite structures yields several obstacles due to the high stability of both the parent perovskite and the Ruddlesden-Popper structures and the occurrence of parasitic structures.

Elucidation of the Reaction Mechanism for Hydrogen Decomposition on [NiFe] Hydrogenase

Elucidation of the Reaction Mechanism for Hydrogen Decomposition on [NiFe] Hydrogenase

Effect of adding different percentages of HfCl4 on the hydrogen storage properties of MgH2

Magnesium hydride (MgH2) is the best candidate material to store hydrogen in the solid-state form owing to its advantages such as good reversibility, high hydrogen storage capacity (7.6 wt%), low raw material cost and abundance in the earth. Nevertheless, slow desorption/absorption kinetics and high thermodynamic stability are two issues that have constrained the commercialization of MgH2 as a solid-state hydrogen storage material. So, to boost the desorption/absorption kinetics and to alter the thermodynamics of MgH2, hafnium tetrachloride (HfCl4) was used as a catalyst in this study. Different percentages of HfCl4 (5, 10, 15 and 20 wt%) were added to MgH2 and their catalytic influences on the hydrogen storage properties of MgH2 were investigated. Results showed that the 15 wt% HfCl4-doped MgH2 sample was the best composite to enhance the hydrogen storage performance of MgH2. The onset decomposition temperature of the 15 wt% HfCl4-doped MgH2 composite was decreased by ~75 °C compared to as-milled MgH2. Meanwhile, the desorption/absorption kinetic measurements showed an improvement compared to the undoped MgH2. From the Kissinger analysis, the apparent dehydrogenation activation energy was 167.0 kJ/mol for undoped MgH2 and 102.0 kJ/mol for 15 wt% HfCl4-doped MgH2. This shows that the HfCl4 addition reduced the activation energy of the hydrogen decomposition of MgH2. The desorption enthalpy change calculated by the van't Hoff equation showed that the addition of HfCl4 to MgH2 did not affect the thermodynamic properties. Scanning electron microscopy showed that the size of the MgH2 particles decreased and there was less agglomeration after the addition of HfCl4. It is believed that the decrease in the particle size and in-situ generated MgCl2 and Hf-containing species had synergistic catalytic effects on enhancing the hydrogen storage properties of the HfCl4-doped MgH2 composite.