Bimetallic catalysts offer unique advantages for improving the hydrogen storage performance of MgH2. Herein, Ni3Fe/BC nanocatalysts were prepared via a simple solid phase reduction method using a ...low-cost biomass charcoal (BC) material as the carrier. The onset temperature of hydrogen release for the MgH2 + 10 wt% Ni3Fe/BC composite was 184.5 °C, which is 155.5 °C lower than that of pure MgH2. The dehydrogenated composite starts to absorb hydrogen at as low as 30 °C and is able to absorb 5.35 wt% of H2 within 10 min under 3 MPa hydrogen pressure at 150 °C. In comparison to pure MgH2, the apparent activation energies of dehydrogenation and rehydrogenation of MgH2 + 10 wt% Ni3Fe/BC were reduced by 52.89 kJ mol−1 and 23.28 kJ mol−1, respectively. The hydrogen storage capacity of the composite was maintained in 20 de/rehydrogenation cycles, indicating a good cycling stability. X-Ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray energy dispersive spectroscopy (EDS) characterization reveal that the in situ formation of multiphases Mg2Ni and Fe catalysts during the hydrogen uptake and release reaction and the transformation of Mg2Ni/Mg2NiH4 together contribute to the superior hydrogen adsorption and desorption performance of MgH2.
At present, catalyst doping has been widely concerned by researchers as an effective method to improve the hydrogen storage performance of MgH2. Herein, it is confirmed that MnMoO4 rod catalyst can ...effectively improve the hydrogen storage performance of MgH2. According to the experimental results, MgH2+10 wt%MnMoO4 composite material starts dehydrogenation at about 220 °C, which is about 140 °C lower than MgH2 without additives. The initial dehydrogenation capacity of 6 wt% can be reached within 10min at 300 °C. After complete dehydrogenation, H2 can be absorbed below 55 °C, and 4.34 wt% H2 can be absorbed within 15 min at 150 °C and 3 MPa hydrogen pressure. In addition, the activation energy of dehydrogenation of MgH2 decreased about 45 kJ mol−1. Furthermore, hydrogen storage capacity of MgH2 can still be maintained at 5.85 wt% after 20 cycles. The synergy between the in-situ formed Mn and MgMo2O7 may help promote the dissociation and diffusion of H2 along the Mg/MgH2 interface, thereby improving the hydrogen storage performance of MgH2.
Display omitted
•MgH2–MnMoO4 composite system was reported for the first time.•MgH2+10 wt%MnMoO4 composite material starts dehydrogenation at about 220 °C.•MgH2–MnMoO4 composites showed promising kinetic properties.•MgO, Mn and MgMo2O7 were formed in situ during the reaction.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Accurately estimating the state of charge (SOC) is imperative for ensuring safe and dependable battery utilization. However, accurately calculating SOC for LiMn
0.6
Fe
0.4
PO
4
/LiNi
0.5
Co
0.2
Mn
...0.3
O
2
(LMFP/NCM) batteries can be challenging due to their two flat voltage platforms and significant temperature dependence. To improve estimation accuracy, a battery SOC estimation method based on a dual Kalman filter (DKF) was proposed. The adaptive unscented Kalman filter (AUKF) process starts with the introduction of Schmidt orthogonal transform, which is subsequently employed in the algorithm’s sampling point selection procedure to mitigate computational complexity. Moreover, the utilization of the multi-innovation theory serves to enhance the accuracy of algorithmic estimation. The extended Kalman filter is used to identify the parameters of the equivalent circuit model online while simultaneously carrying out battery SOC estimation. This approach mitigates the impact of variations in battery model parameters during charging and discharging processes. Under complex conditions, the algorithm’s average error is less than 0.53%, demonstrating its effectiveness in improving SOC estimation accuracy as evidenced by comparison between experiment and simulation results. It has reference significance for optimizing LMFP/NCM battery SOC estimation.
Due to its high hydrogen storage efficiency and safety, Mg/MgH
stands out from many solid hydrogen storage materials and is considered as one of the most promising solid hydrogen storage materials. ...However, thermodynamic/kinetic deficiencies of the performance of Mg/MgH
limit its practical applications for which a series of improvements have been carried out by scholars. This paper summarizes, analyzes and organizes the current research status of the hydrogen storage performance of Mg/MgH
and its improvement measures, discusses in detail the hot studies on improving the hydrogen storage performance of Mg/MgH
(improvement measures, such as alloying treatment, nano-treatment and catalyst doping), and focuses on the discussion and in-depth analysis of the catalytic effects and mechanisms of various metal-based catalysts on the kinetic and cyclic performance of Mg/MgH
. Finally, the challenges and opportunities faced by Mg/MgH
are discussed, and strategies to improve its hydrogen storage performance are proposed to provide ideas and help for the next research in Mg/MgH
and the whole field of hydrogen storage.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Due to its high hydrogen storage efficiency and safety, Mg/MgHsub.2 stands out from many solid hydrogen storage materials and is considered as one of the most promising solid hydrogen storage ...materials. However, thermodynamic/kinetic deficiencies of the performance of Mg/MgHsub.2 limit its practical applications for which a series of improvements have been carried out by scholars. This paper summarizes, analyzes and organizes the current research status of the hydrogen storage performance of Mg/MgHsub.2 and its improvement measures, discusses in detail the hot studies on improving the hydrogen storage performance of Mg/MgHsub.2 (improvement measures, such as alloying treatment, nano-treatment and catalyst doping), and focuses on the discussion and in-depth analysis of the catalytic effects and mechanisms of various metal-based catalysts on the kinetic and cyclic performance of Mg/MgHsub.2. Finally, the challenges and opportunities faced by Mg/MgHsub.2 are discussed, and strategies to improve its hydrogen storage performance are proposed to provide ideas and help for the next research in Mg/MgHsub.2 and the whole field of hydrogen storage.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Magnesium hydride (MgH2) is considered to be one of the most promising hydrogen storage materials owing to its safety profile, low cost and high hydrogen storage capacity. However, its slow kinetic ...performance and thermal stability limit the possibility of practical applications. Herein, it is confirmed that the hydrogen storage performance of MgH2 can be effectively improved via doping with a flake Ni nano-catalyst. According to experimental results, a MgH2 + 5 wt% Ni composite begins to dehydrogenate at almost 180 °C and could dehydrogenate 6.7 wt% within 3 min at 300 °C. After complete dehydrogenation, hydrogen can be absorbed below 50 °C, and 4.6 wt% H2 can be absorbed at 125 °C within 20 min at a hydrogen pressure of 3 MPa. In addition, the activation energies of MgH2 hydrogen absorption and dehydrogenation decreased by 28.03 and 71 kJ mol-1, respectively. Cycling stability testing showed that the hydrogen storage capacity decreases significantly in the first few cycles and decreases slightly after 10 cycles. Furthermore, it was found that Mg2Ni/Mg2NiH4 was formed initially during the hydrogen absorption or desorption reaction on the surface of Mg/MgH2, which acted as a "hydrogen pump", accelerating the rates of hydrogen absorption and desorption.
CeOsub.2 is an important rare earth (RE) oxide and has served as a typical oxygen storage material in practical applications. In the present study, the oxygen storage capacity (OSC) of CeOsub.2 was ...enhanced by doping with other rare earth ions (RE, RE = Yb, Y, Sm and La). A series of Undoped and RE–doped CeOsub.2 with different doping levels were synthesized using a solvothermal method following a subsequent calcination process, in which just Ce(NOsub.3)sub.3∙6Hsub.2O, RE(NOsub.3)sub.3∙nHsub.2O, ethylene glycol and water were used as raw materials. Surprisingly, the Undoped CeOsub.2 was proved to be a porous material with a multilayered special morphology without any additional templates in this work. The lattice parameters of CeOsub.2 were refined by the least–squares method with highly pure NaCl as the internal standard for peak position calibrations, and the solubility limits of RE ions into CeOsub.2 were determined; the amounts of reducible–reoxidizable Cesup.n+ ions were estimated by fitting the Ce 3d core–levels XPS spectra; the non–stoichiometric oxygen vacancy (Vsub.O) defects of CeOsub.2 were analyzed qualitatively and quantitatively by O 1s XPS fitting and Raman scattering; and the OSC was quantified by the amount of Hsub.2 consumption per gram of CeOsub.2 based on hydrogen temperature programmed reduction (Hsub.2–TPR) measurements. The maximum OSC of CeOsub.2 appeared at 5 mol.% Yb–, 4 mol.% Y–, 4 mol.% Sm– and 7 mol.% La–doping with the values of 0.444, 0.387, 0.352 and 0.380 mmol Hsub.2/g by an increase of 93.04, 68.26, 53.04 and 65.22%. Moreover, the dominant factor for promoting the OSC of RE–doped CeOsub.2 was analyzed.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Magnesium hydride (MgH2) has become a very promising hydrogen storage material because of its high hydrogen storage capacity, good reversibility and low cost. However, high thermodynamic stability ...and slow kinetic performance of MgH2 limit its practical application. In the past few decades, many alternative methods have been designed to solve this problem. A large number of studies have demonstrated that the use of metal catalyst doping modification, MgH2 nanocrystallization and other methods can greatly improve the hydrogen absorption and dehydrogenation performance of MgH2. Therefore, this paper reviews and summarizes the modification effect of transition metal catalyst doping on the hydrogen storage performance of MgH2, especially the catalysis on the de/rehydrogenation performance of MgH2. In addition, promoting effects of carbon materials, transition metal alloys and compounds on the hydrogen storage performance of MgH2 were also summarized. Finally, the existing problems and challenges of MgH2 as hydrogen storage materials are discussed, and some possible strategies are proposed.
In this review paper, we have recorded various metal catalysts with excellent catalytic performance for Mg/MgH2. The catalytic properties of different types of catalysts were clearly described and summarized in detail. At the same time, some current challenges are pointed out and some possible strategies are given. It is believed that this manuscript can provide some ideas and guidance for researchers who are interested in the field of hydrogen storage in the future.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
Hydrogen storage technology is related to the process of hydrogen energy market. Efficient and safe hydrogen storage materials have always been the goal pursued by people. In the past few ...years, oceans of materials for hydrogen storage have been researched, MgH
2
is considered to be one of the most potential hydrogen storage materials due to its high hydrogen storage capacity, good reversibility and price advantage. However, its development has been limited by its good thermodynamic stability and slow dehydrogenation kinetics. In this paper, the improvement of hydrogen storage performance of MgH
2
is summarized from catalyst doping, MgH
2
nanosizing, alloying and the construction of composite system. In particular, catalyst doping and MgH
2
nanosizing will be more effective modification strategies. With the development of nanotechnology, monatomic catalyst will also become a research hotspot. In view of the changes in thermodynamic properties caused by the nanofabrication of MgH
2
, the loadless freestanding nano MgH
2
will undoubtedly receive more attention.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
