The crystal structure of magnesium hydride affects the properties of magnesium for hydrogen storage. The crystal phase and dehydriding temperature of magnesium hydride from magnesium by high-energy ball milling under hydrogen atmosphere with anthracite carbon, which was prepared from anthracite coal by demineralization and carbonization, as milling aid was investigated. The HRTEM observation and XRD characterization showed that the Mg hydrided into nanocrystalline β-MgH2of tetrahedral crystal structure and γ-MgH2of orthorhombic crystal structure during milling under 1 MPa of hydrogen, and the γ-MgH2increased with the extension of milling time. The DSC analysis showed that the endothermic peak of γ-MgH2was 53 °C lower than that of β-MgH2in the material from 10 h of milling.
Magnesium-based hydrogen storage materials were prepared by reactive milling of magnesium under hydrogen atmosphere with crystallitic carbon, prepared from anthracite coal, as milling aid. The XRD analysis shows that in the presence of 30 wt.% of crystallitic carbon, the Mg easily hydrided into β-MgH2of crystal grain size 29.7 nm and a small amount of γ-MgH2after 3 h of milling under 1 MPa H2. The enthalpy and entropy changes of the hydrogen desorption reaction are 42.7 kJ/mol and 80.7 J/mol K, respectively, calculated by the vant Hoff equation from thep-C-Tdata in 300-380°C.
Magnesium-based hydrogen storage powders were prepared by reactive milling under hydrogen atmosphere. The crystallitic carbon, prepared from anthracite coal by demineralization and carbonization, was used as milling aid and synergic hydrogen storage additive of magnesium. Dispersive powders of particle size about 20 to 60 nm and hydrogen capacity of 4.78 wt.% were prepared from magnesium with 40 wt.% of crystallitic carbon by 3 h of milling under 1 MPa of hydrogen atmosphere. The hydrogen stored in carbon increased with the addition of Al, Mo, Co and Fe. FT-IR showed that the carbon atoms at the edges of crystallitic carbon particles were hydrogenated into C-H during reactive milling with hydrogen. The initial dehydrogenation temperature of hydrogen-storage material 60Mg40C is 275.8 °C, and its dehydrogenation plateau pressure at 300 °C is 0.2 MPa and the length of the plateau is 5.0 wt.% of hydrogen capacity.
The existential state of protein in complexes directly affects the performance and applications of the composite materials. The interlayer space changes of montmorillonite in the protein / montmorillonite (MMT) composite were identified by X-ray diffraction (XRD). And the interaction between protein and MMT were analyzed by Fourier transform infrared spectrometry (FT-IR) and UV/vis spectrophotometry. The loading amount of bovine serum albumin (BSA) onto MMT was calculated from the TG data. The types of adsorption isotherm of BSA onto montmorillonite were analyzed. From the above analysis, it can be concluded that the structure of proteins in the montmorillonite interlayers has been changed, and the hydrogen bond and Van der Waals force between the BSA molecules and montmorillonite crystal layers are intensified. The α-helix content of BSA molecules reduces while random coil increases. The protein shows a state of being squashed.
The Suaeda salsa L. has been discovered to be a great potential as a new kind of renewable energy. The pyrolytic characteristics and kinetics of S. salsa were investigated at heating rates of 5, 10, 20, 30°C/min under nitrogen atmosphere respectively. The most probable mechanism function was deduced using Popescu method, which is a three-dimensional diffusion function (), and n=-2/3. Activation energy and pre-exponential factors were studied through the FWO, KAS and Popescu methods. The results showed that the activation energy increase as the pyrolysis process and three stages were observed in the TG-DTG curves of S.salsa. The results showed that S.salsa as a pyrolysis feedstock has a great potential and a good prospect in bio-oil production.
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