Exploring reliable hydrogenation catalysts to remove trace olefins in aromatic hydrocarbons through hydrogenation is an important topic. In this paper, a bimetallic Cu–Ru/montmorillonite (Cu–Ru/M) catalyst was prepared using a step-by-step impregnation method, and the effects of bimetallic catalysts on removing olefins were assessed. The catalysts were characterized using X-ray diffraction, Brunauer–Emmett–Teller specific surface area, inductively coupled plasma atomic emission spectrometry, high-resolution transmission electron microscopy and temperature-programmed reduction of H2. The results show that there is a strong interaction between Cu and Ru on the Cu–Ru/M catalyst, which improves the dispersion of the metals on the surface of the support M. The hydrogen spillover phenomenon of Cu–Ru/M enhances its activity and adsorption capacity for hydrogen species. The catalytic performance test confirmed that the bimetallic catalyst has significantly greater activity and stability. The optimal loadings are 5% copper and 1% ruthenium, and the performance of this catalyst is comparable to those of noble-metal Pt/M catalysts.

The Ti-Zr-Ni quasicrystal alloys have prospected to be one of the promising materials for hydrogen storage. This is because this type of quasicrystal contains 140 interstitial sites (T-sites) constituted in the Bergman Cluster that could accommodate hydrogen. The number of available sites is far greater than the number found in regular crystals, therefore the improvement of hydrogen storage capacity could be expected. For this study, we focus on the effect of substitution of Cr, in place of Ni in Ti-Zr-Ni amorphous and quasicrystal alloys. The studied samples are synthesized by the combination of mechanical alloying and sintering process. The subsequent measurements of electrochemical hydrogenation and dehydrogenation are carried out by a three-electrode cell at room temperature. The studied samples are structurally characterized by X-ray diffraction and their morphology is analyzed by scanning electron microscope and transmission electron microscope. The influence of the 4th substituted element on the possibility of a new-formed Cr quasicrystalline phase and the potential improvement of hydrogenation and dehydrogenation kinetics for both amorphous and quasicrystalline phase is evaluated. Our measurements showed the maximum discharge capacity achieved by Ti45Zr38Ni7Cr10 amorphous and Ti45Zr38Ni12Cr5 i-phase electrodes at a current density of 15 mA·g-1 to be 9.8 mAh·g-1and 55.2 mAh·g-1 respectively. The maximum estimated H/M value for the Ti45Zr38Ni12Cr5 i-phase electrode reached 1.36. These results are encouraging and show the merit of the usage of quasicrystals as hydrogen storage materials.

The strong interactions between Mg and Ni/NiH4 are attributed to harsh operating conditions and difficulties for H2 release, restricting the practical applications of the Mg-based hydrides. In this study, a new method of interstitial nonmetals co-doping was proposed to reduce the strong interactions. The calculation results showed that the method of interstitial nonmetals co-doping causes a more significant reduction in the thermal stability of Mg-based hydrides, as compared with the methods of either single transition metal or nonmetal doping. To determine the influence mechanism, a theoretical study was conducted based on the first-principles calculations. The computations demonstrated that the criss-cross action between B–Ni and N–Mg bonds weakens the bonding effects between Mg and Ni/NiH4. Besides, the mutual interactions between nonmetals and H atoms could weaken Ni–H bonding effects and stimulate the breaking of stable NiH4 clusters, thereby facilitating the release of H2 from the hydride.

Combining density functional theory calculations and temperature programmed desorption (TPD) experiments, the adsorption behavior of various sulfur containing compounds, including C2H5SH, CH3SCH3, tetrahydrothiophene, thiophene, benzothiophene, dibenzothiophene, and their derivatives on the coordinately unsaturated sites of Mo27Sx model nanoparticles, are studied systematically. Sulfur molecules with aromaticity prefer flat adsorption than perpendicular adsorption. The adsorption of nonaromatic molecules is stronger than the perpendicular adsorption of aromatic molecules, but weaker than the flat adsorption of them. With gradual hydrogenation (HYD), the binding affinity in the perpendicular adsorption modes increases, while in flat adsorption modes it increases first, then decreases. Significant steric effects on the adsorption of dimethyldibenzothiophene were revealed in perpendicular adsorption modes. The steric effect, besides weakening adsorption, could also activate the S–C bonds through a compensation effect. Finally, by comparing the theoretical adsorption energies with the TPD results, we suggest that HYD and direct-desulfurization path may happen simultaneously, but on different active sites.

Ti-based quasicrystals are well known to store a high capacity of hydrogen exceeding the density of liquid hydrogen. This fact is due to that TiZrNi contain a large number of tetrahedral sites formed with Ti and Zr atoms that are chemical affinity with hydrogen. TiZrNi quasicrystal absorbs hydrogen up to host metal ratio (H/M) value near to 2.0. The disadvantage is due to the low equilibrium pressure. To solve this problem, we substituted Ti with a small amount of vanadium (V), with the nominal composition Ti45−x VxZr38Ni17 (x = 5, 10, 15) and synthesized by mechanical alloying. The subsequent annealing in vacuum conditions converted the amorphous into an icosahedral quasicrystal (I-phase) with face-centered cubic (FCC) Ti2Ni-type crystal. As the results, we investigated the discharge capacity for both amorphous and quasicrystal electrodes using three electrodes system (working, reference and counter electrodes) at room temperature. The highest discharge capacities obtained were 81.45 mAh/g recorded for amorphous electrode and 318.4 mAh/g for quasicrystal whose compositions is Ti35V10Zr38Ni17 at discharge current density of 15 mA/g. X-ray diffraction measurement was performed to provide the structural information on materials before and after hydrogenation. Microstructures of the materials were studied using an electron scanning microscope and the chemical compositions were confirmed using an EDX-analysis.

Anti-organic fouling performance of titanium dioxide (TiO2) can be enhanced by extending its light absorption and photocatalytic capability from ultra-violet to the visible range through hydrogenation. In this work, we aim at studying the impact of hydrogenation on the performance of both electron beam-deposited TiO2 thin films and hydrothermally grown TiO2 nanostructures on titanium substrates. Hydrogenation of these TiO2-deposited titanium substrates (TiO2/Ti) are achieved in relatively low-temperature low-pressure chemical vapor deposition chamber without any noble diatomic hydrogen dissociation catalyst, such as platinum. Our study shows that these hydrogenated TiO2/Ti have better light absorption ability and the titanium substrate itself serves as the active catalyst for hydrogen dissociation and diffusion. By applying hydrogenation to the TiO2 nanostructures, we can enhance photocatalytic performance by 50% through methylene blue degradation experiments. We have also evaluated the effect of hydrogenation on carrier density and mobility in TiO2/Ti. We recommend the hydrogenation of hydrothermally grown TiO2 nanostructure on titanium substrates for scalable photocatalytic applications.

{001} facets dominant TiO2 nanosheets have attracted intensive attention in the photocatalytic field, due to their undercoordinated Ti5c centers, higher surface energy, and photocatalytic activity than those of any other low-energy facet. However, a fluorine-rich (001) surface is controversial to the photocatalytic activity of TiO2 nanocrystals. We have removed the surface F atoms bonding with Ti by hydrogenation method successfully, and found that {001} facets dominant TiO2 nanosheets without the terminated F atoms showed dramatic enhancement in the photocatalytic activity. Moreover, the clean (001) surface was more in favor of the deposition of PdO than the fluorine-rich surface, and the amorphous structure from the hydrogenation is beneficial to the reduction of PdCl42− to Pd nanoparticles. The PdO attached on {001} facets and the amorphous structure promoted the separation of charge carriers, and Pd nanoparticles transferred plasmonic-induced electrons to the conduction band of hydrogenated TiO2 under simulated solar irradiation. Thus, a significantly enhanced photocatalytic activity of Pd–H–TiO2 is achieved on degrading organic environmental pollution, due to the synergy of palladium species and hydrogenation on {001} facets exposed TiO2.

Bimetallic catalyst Ni–Fe/SiO2 microspheres were obtained by reducing bimetallic (Ni,Fe2+)3Si2O5(OH)4 microspheres with controllable morphology structure in situ under the hydrogen atmosphere at 650 °C, which are synthesized via one-step self-template method under hydrothermal conditions. The TEM images indicate the formation process of the different morphology and the synthesis conditions of bimetallic Ni–Fe silicate were obtained. Bimetallic catalyst Ni–Fe/SiO2 (reduced) hollow microspheres had the smaller surface area and the bigger pore diameter than that of (Ni,Fe2+)3Si2O5(OH)4 (unreduced) hollow microspheres because the reduction reaction under high temperature may make part pores in nanosheets collapsing and metal particles aggregating easily for the strong magnetism. For synergistic effect of nickel ion and iron ion, the reaction conditions of the chosen catalyst with higher activity were decreased from 140 °C–24 h + 180 °C −12 h for iron silicate hydroxide to 140 °C–12 h. Ni–Fe/SiO2 core-shell microspheres exhibited excellent catalytic activity with a conversion of nitrobenzene reaching 94% within 2 h, which is 82% higher than Fe/SiO2.

The hydrogenation behavior of Ti–44Al–6Nb (at.%) alloy was studied at temperature range of 1373–1693 K, and the effect of hydrogen on hot deformability was tested on Gleeble-1500D thermo-simulation machine. It is found that the lnCH increases linearly with 1/T, and hydrogen content increases with increasing of hydrogen time and flow rate logarithmically. The positive heat of solution of hydrogen denotes that hydrogen absorption in TiAl alloys is an endothermic reaction. The results also show that hydrogen promotes the lamellar colony size and lamellar spacing because that hydrogen can promote the diffusion of elements. There is more residual B2 phase in the hydrogenated alloy revealing that hydrogen stabilizes the B2 phase during hydrogenation. The nanohardness and elastic modulus of the alloy are decreased from 4.4 and 213.5 GPa to 4.2 and 199.8 GPa after hydrogenation with 0.033 wt% H. Thermal simulation results show that the peak stress is decreased by 30% after hydrogenation with 0.033 wt% H which corresponds to decreasing the deformation temperature by about 50 K. This is attributed to hydrogen-promoted dynamic recrystallization and dislocation movement.

Robust time-averaged molecular dynamics has been developed to calculate finite-temperature elastic constants of a single crystal. We find that when the averaging time exceeds a certain threshold, the statistical errors in the calculated elastic constants become very small. We applied this method to compare the elastic constants of Pd and PdH0.6 at representative low (10 K) and high (500 K) temperatures. The values predicted for Pd match reasonably well with ultrasonic experimental data at both temperatures. In contrast, the predicted elastic constants for PdH0.6 only match well with ultrasonic data at 10 K; whereas, at 500 K, the predicted values are significantly lower. We hypothesize that at 500 K, the facile hydrogen diffusion in PdH0.6 alters the speed of sound, resulting in significantly reduced values of predicted elastic constants as compared to the ultrasonic experimental data. Literature mechanical testing experiments seem to support this hypothesis.

As materials science is becoming components development and systems technology, hydrogen economy is approaching your porch. Welcome!

Hydrogen mobility can now be purchased from the shelf. Fuel cell electric vehicles from various well-known car manufacturers are now available. The number of hydrogen filling stations in Europe is increasing at a rate that long-distance tours become less and less adventurous. The efforts of fuel cell researchers have paid off. Suppliers of components and systems for hydrogen infrastructure are anticipating business. Meanwhile, basic science in electrochemistry and materials research is continuing, with surprises such as the discovery of a proton polaron which are adding to the progress in fundamental understanding of energy materials in operation. Has the long awaited hydrogen economy finally arrived?

It is demonstrated that Na doping can significantly improve the hydriding performance of Mg2Ni under an isobaric-isothermal condition of 2 MPa H2 and 350 °C. This is achieved via an increase of the interphase grain boundary area and density of dislocations as compared to the Na-free material. Significant enrichment of Na+ cations on the alloys' surface coupled with the catalytic effect of metallic Ni are suggested to increase the hydrogen–metal bonding strength facilitating hydrogen adsorption/dissociation. The mechanisms of hydrogen absorption are discussed based on a nucleation and growth theory. Additionally, by means of in situ synchrotron powder x-ray diffraction, the transition of Mg2Ni into the stable Mg2NiH0.3 is observed in real-time.

Several diverse types of UH3-based hydrides can be prepared by hydrogenation of bcc U-based alloys. Pair Distribution Function (PDF) analysis using high-energy X-rays identified that the (UH3)1-x Mox hydrides are nanocrystalline, with the structure motif based mainly on the β-UH3 structure. α-UH3 represents a minority component. On the other hand, PDF of the (UH3)1-x Zrx hydrides corresponds well to the α-UH3 crystal structure. All the hydrides are ferromagnetic, with the Curie temperature T C reaching up to 203 K.

Cr, V, and Fe amino borohydride complexes were synthesized using a solution based approach. Thermogravimetric Analysis with simultaneous Differential Scanning Calorimetry was used to investigate their decomposition behavior. The synthesized Cr and Fe complexes exhibited significant hydrogen release around 100 °C. The synthesized V complex showed a large mass loss at temperatures between 50 °C and 100 °C and release of amine byproducts. FTIR of decomposed intermediates showed the decomposition of Cr amino borohydride occurs through the simultaneous loss of hydrogen from both the borohydride and amino ligands, while the Fe complex displays preferential dehydrogenation of the borohydride over the amino ligand. The decomposed products take on a BN type structure when heated to 400 °C.

Ti was added to Mg–Ni alloy (Mg95Ni5) by a novel hydriding combustion synthesis (HCS) process. The effect of Ti on hydrogen absorption/desorption kinetics of Mg95Ni5 was investigated. The results showed that Ti had superior catalytic effects on hydrogen storage properties of Mg95Ni5, which required only 80 s to reach its saturated hydrogen absorption capacity of 6.29 wt% at 473 K and released 5.49 wt% hydrogen within 900 s at 553 K. Based on an Arrhenius analysis, the activation energy of the hydrogen desorption process was 80.8 kJ mol−1 for the main phase of MgH2 in the Ti-doped Mg95Ni5. The excellent hydriding/dehydriding properties were related to the existence of TiH1.924, which improved the efficiency of mechanical milling and was helpful in the refinement of the crystallite size of MgH2, resulting in more fresh surface area and grain boundary area. Besides, it was thought to restrain the Mg particles from growth during the hydrogenation/dehydrogenation cycles.

The storage and transportation barriers of hydrogen are cleared by sodium metal “Source of Hydrogen” produced from warm seawater discharged at the nuclear power plant. The warm seawater is electrolyzed to produce sodium hydroxide; which is then subjected to molten-salt electrolysis by surplus power of the plant to produce sodium metal “a hydrogen generator”. The seawater contains salt most after fresh water; which is the raw material of sodium metal and is never drained. The sodium metal is transported to the electric power station in a consumption place, where a large amount of hydrogen is generated immediately by adding water on the sodium metal for power generation. Salt, the raw material of sodium metal, is in the sea over the world, and it is not necessary to worry about the maldistribution and exhaustion.

TiO2 has attracted tremendous research interest for photocatalytic water splitting, solar hydrogen generation, environmental pollution removal, dye-sensitized solar cells, lithium-ion batteries, supercapacitors, and field emission. Microwave absorption materials (MAMs) play important roles in many military (e.g., the stealth coating on the B-2 bomber) and civil (e.g., telecommunications, noise reduction, information security, signal, and data protection) applications. However, TiO2 is not a good MAM due to its poor absorption in the microwave region. Here, we report that via hydrogenation excellent and tunable microwave absorption is achieved with hydrogenated TiO2 nanocrystals. After hydrogenation, 4.3x and 103x improvements have been obtained in storing and dissipating the electric energy of the microwave electromagnetic field. Their permittivity values are higher than those of the current carbonaceous MAMs. Instead of relying on the dipole rotation or ferromagnetic resonance mechanisms for traditional MAMs, the hydrogenated TiO2 nanocrystals work as good MAMs based on a newly proposed collective-movement-of-interfacial-dipole (CMID) mechanism. Although there is still no direct physical evidence of the interface effects of the CMID mechanism, the CMID as a hypothesis at this point successfully explained the origin of the enhanced microwave absorption of the hydrogenated TiO2 nanoparticles. This study thus may open new applications for TiO2 nanocrystals and also stimulate new approaches for new MAM development.

γ-U alloys with Mo or Zr are more resistant to hydrogen than U metal. High pressures of H are needed to produce hydrides. Amorphous structure of UH3Mox can be represented as the cubic structure of β-UH3 type with grain size around 1 nm. UH3Zrx are formed in the cubic α-UH3 type of structure. All the hydrides are ferromagnets, with magnetic parameters (magnetic moments, Curie temperature) exceeding those of β-UH3 (0.9 μB/U, 165-170 K). It is deduced that α-UH3 has magnetic properties very similar to β-UH3, despite rather different U-U spacing.

The electronic band structures of the hydrogenated graphene-like materials, graphane, silicane, and germanane, under tensile strains are calculated using first-principles calculation. The imposed tensile strain is in either the armchair or zigzag direction in the honeycomb lattice. It is found that the band gap of graphane gradually increases with the increase of the strain, whereas the band gaps of silicane and germanane decrease with the increase of the strain. There is little effect of the direction of the imposed strain on such strain dependences.

TiO2-supported bimetallic Au-Rh and Au-Pd nanocrystals were synthesized using both impregnation and colloidal approaches employing HAuCl4 and RhCl3 as precursors. The as-obtained bimetallic catalysts were then supported onto TiO2 rutile nanorods in order to provide catalytic systems with well-defined metal-support interactions for HRTEM characterization. The results revealed the superiority of the colloidal approach over the impregnation technique to obtain bimetallic nanoparticles (4 nm in size) with tunable composition. However, for Au-Rh/TiO2, optimization of the procedure of the sol immobilization onto the TiO2 support was required to avoid possible Rh re-dissolution. Preparation of Au-Pd/TiO2 followed the same procedure but with more acidic conditions necessary to perform immobilization on the support. UV-vis spectroscopy and XRD results suggest formation of a Rh-rich shell over an Au core center for Au-Rh NPs, while Au-Pd NPs present a pure alloy structure. Au-Rh/TiO2 was used for performing the high-pressure hydroconversion of tetralin in the presence or not of H2S. The results indicate a strong thioresistance induced by the addition of Au to Rh.