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The present study successfully synthesized a Yb 2 O 3 @C composite catalyst using an enhanced chemical blow molding carbonization method. The characterization results showed that the catalyst was highly dispersed in the porous carbon matrix by Yb 2 O 3 nanoparticles. And the catalyst has developed pore structure, high specific surface area and high defect density. Yb 2 O 3 @C was mixed with the Mg 96 La 3 Ni alloy through ball milling, and the impact of varying amounts of Yb 2 O 3 @C on the hydrogen storage performance of Mg 96 La 3 Ni was comprehensively investigated. The research findings indicate that the addition of Yb 2 O 3 @C notably refines the Mg-based alloy, leading to an increase in both specific surface area and the count of active sites. Furthermore, Yb 2 O 3 @C markedly enhances the hydrogen sorption kinetics of Mg 96 La 3 Ni, with the most substantial impact noted at a Yb 2 O 3 @C content of 3 wt %. Additionally, the incorporation of Yb 2 O 3 @C substantially decreases the dehydrogenation activation energy of the alloy, while leaving its thermodynamic properties unaffected. Yb 2 O 3 nanoparticles and the carbon matrix work synergistically to promote both nucleation reactions and hydrogen diffusion. This study presents a novel strategy for enhancing the performance of hydrogen storage materials based on magnesium. • Yb 2 O 3 @C composite catalyst was successfully synthesized. • Yb 2 O 3 @C catalyst provides abundant active sites and fast hydrogen migration channels. • Yb 2 O 3 @C addition refines alloy grains, increases surface area and active sites. • Yb 2 O 3 @C greatly improved hydrogen absorption and dehydrogenation kinetics of Mg 96 La 3 Ni. • Yb 2 O 3 @C lowered dehydrogenation activation energy via enhanced hydrogen nucleation and diffusion, unchanged thermodynamics. [ABSTRACT FROM AUTHOR]

GdO@C composite catalyst synthesis was achieved through a novel chemical blowing carbonization method. Nano-sized GdO uniformly distributed throughout a high-surface-area, defect-laden carbon matrix translates to catalytic performance. To elucidate the influence of GdO@C doping on hydrogen storage, Mg 96 La 3 Ni-GdO@C alloys were prepared by ball milling, and the hydrogen storage performance was evaluated. Adding GdO@C can refine the alloy particles, which boosts the surface area and the number of active sites available for the hydrogenation reaction. GdO@C greatly enhanced the de/hydriding kinetics of the alloys, with 1 wt% GdO@C exhibiting the optimal effect. At 360 °C, this material could quickly absorb a large amount of hydrogen (84.4 wt% of its maximum capacity) in just 2 min, but it only took 1.6 min to release a small amount (3 wt%). Doping the alloys with GdO@C reduced the activation energy barrier for dehydrogenation (to 106.3 kJ/mol) and shifted the endothermic peak to a lower temperature (334 °C). Nevertheless, there was no improvement observed in the thermodynamic properties of the composites, as the enthalpy change remained constant at 77.1 kJ/mol. • GdO@C composite catalyst was successfully synthesized by an improved chemical blowing method • The GdO@C has a mesoporous structure, large specific surface area, and high defect density. • GdO@C addition refines particle size, increases surface area and active sites. • GdO@C greatly improved hydrogen de/hydriding kinetics of Mg 96 La 3 Ni. • Adding 1 wt% GdO@C lowered the alloy's dehydrogenation activation energy to 106.3 kJ/mol. • The addition of GdO@C catalyst does not effectively improve the thermodynamic properties of the alloy [ABSTRACT FROM AUTHOR]

This study successfully synthesized Eu 2 O 3 @C composite catalyst by an improved chemical blowing method. The Eu 2 O 3 nanoparticles in this catalyst are highly dispersed within a porous carbon matrix, exhibiting a well-developed mesoporous structure, a large specific surface area, and a high density of defects. Eu 2 O 3 @C was mixed with the Mg 96 La 3 Ni alloy through ball milling, and the impact of varying amounts of Eu 2 O 3 @C on the hydrogen storage performance of Mg 96 La 3 Ni was comprehensively investigated. The results showed that Eu 2 O 3 @C markedly enhances the de/hydrogenation kinetics of Mg 96 La 3 Ni, with the most substantial impact noted at a Eu 2 O 3 @C content of 2 wt %. At 360 °C, 77.3 % of the maximum hydrogen capacity could be absorbed within 2 min, while only 1.4 min was required to release 3 % of hydrogen. Additionally, Eu 2 O 3 @C markedly decreased the dehydrogenation activation energy of the alloys to 106.3 kJ/mol and reduced the endothermic peak temperature to 347 °C, while leaving thermodynamic properties unaffected. The Mg 96 La 3 Ni–Eu 2 O 3 @C composite exhibits remarkable cyclic stability, retaining its hydrogen storage capacity throughout the cycling process. This study pioneers a novel strategy to elevate the performance of magnesium-based hydrogen storage materials. • Eu 2 O 3 @C composite catalyst was successfully synthesized by an improved chemical blowing method. • The Eu 2 O 3 @C has a mesoporous structure, large specific surface area, and high defect density. • Eu 2 O 3 @C addition refines alloy grains, increases surface area and active sites. • Eu2O3@C significantly enhances Mg–La–Ni de/hydrogenation kinetics, especially at specific Eu2O3@C 2 wt%. • Adding 2 wt% Eu 2 O 3 @C lowered the alloy's dehydrogenation activation energy to 103.6 kJ/mol. [ABSTRACT FROM AUTHOR]

Abstract The thermodynamic properties and phase stability of the Ba-Bi system are investigated computationally and experimentally in the present work. The enthalpies of formation and the finite temperature thermodynamic properties of seven compounds are predicted by first-principles calculations based on density functional theory (DFT), indicating five compounds (BaBi 3 , Ba 11 Bi 10 , Ba 4 Bi 3 , Ba 5 Bi 3 , and Ba 2 Bi) to be stable. Phase relations at 773 K and 858 K with composition x Ba = 0.90 are established by isothermal annealing and powder X-ray diffraction (XRD) to clarify the previously observed phase transition at 796 K. The extremely low chemical activity of Ba in liquid for a wide range of temperatures and compositions indicates very strong short-range ordering in the liquid phase which is modeled in the present work by introducing the Ba 4 Bi 3 and BaBi 3 associates in the liquid phase. Both thermodynamic and phase equilibrium data are then used to evaluate the model parameters in Gibbs energy functions of the five stable compounds and three solution phases of liquid, bcc, and rhombohedral phases by the CALPHAD (CALculation of PHAse Diagram) technique. The present work shows that the Ba-Bi system consists of three eutectic reactions, two peritectic reactions, one peritectoid reaction, and two congruent reactions, as well as that the concentrations of associates are very high in the liquid phase with very low concentration of atomic Ba, which provides the fundamental understanding as to why Bi can be used to remove Ba ions from molten salt solutions. Graphical abstract Image 1 Highlights • A thermodynamic model of the Ba-Bi system with applications in nuclear industry. • Powder XRD is used to clarify the previously observed phase transition. • Explain ability of Bi to remove Ba from electrorefining processes of nuclear waste. [ABSTRACT FROM AUTHOR]

Abstract: The thermodynamic optimization of the Ag–Bi–Sb system was critically carried out by means of the CALPHAD (CALculation of PHAse Diagram) technique. The solution phases, liquid, fcc, rhomb and hcp_A3(ζ) were described by the substitutional solution model. The compound ɛ(Ag3Sb) was treated as the formula (Ag, Sb)3/4(Ag, Sb)1/4 using two sublattice model in the Ag–Bi–Sb ternary system, which is directly from the Ag–Sb binary system. A self-consistent thermodynamic description of the Ag–Bi–Sb system was developed. The vertical sections at 10at.% Bi, 10at.% Ag and 70at.% Ag, the isothermal section at 300K, the projection of the liquidus surfaces, and the complete reaction scheme for the Ag–Bi–Sb system in the literature were reproduced in the present work. [Copyright &y& Elsevier]

Abstract: The thermodynamic modeling and optimization of the Ge–Sb and Ge–Sb–Sn systems were critically carried out by means of the CALPHAD (CALculation of PHAse Diagram) technique. The solution phases, liquid, diamond, bct and rhombohedral, were described by the substitutional solution model. The compound SbSn was treated as the formulae (Ge,Sb,Sn)1(Ge,Sb,Sn)1 in the Ge–Sb–Sn system. A self-consistent thermodynamic description of the Ge–Sb–Sn system was developed. Three isothermal sections at 692, 594 and 518K, the projection of the liquidus surfaces, and the complete reaction scheme for the Ge–Sb–Sn system in the literature were reproduced. [Copyright &y& Elsevier]

Abstract: The Au–Ga system was critically assessed by means of CALPHAD technique. Based on the experimental data in the literature, the excess Gibbs energies of the solution phases (liquid, fcc, orthorhombic) were modeled with the Redlich–Kister equation. The intermetallic compounds αAu7Ga, βAu7Ga2, β′Au7Ga2, γAu7Ga3 and γ′Au7Ga3, which have homogeneity ranges, were treated as the formula Au7(Au,Ga), (Au,Ga)7Ga2, (Au,Ga)7(Au,Ga)2, (Au,Ga)7(Au,Ga)3 and (Au,Ga)7(Au,Ga)3, respectively, using a two-sublattice model with Au and Ga or Au on the first sublattice, Au and Ga or Ga on the second one. The two compounds AuGa and AuGa2 were treated as stochiometric compounds. A set of self-consistent thermodynamic parameters of the Au–Ga system was obtained. [ABSTRACT FROM AUTHOR]