Revealing the micro-and meso-scale hydrogen?induced crack propagation mechanism of high-strength pipeline steel holds significant engineering value for ensuring the safety of hydrogen energy transportation. In this study, a ferrite-cementite interface model with Bagaryatskii crystallographic relationship was established for the pearlite structure formed by eutectoid ferrite (α-Fe) and cementite (Fe₃C) in ferrite?pearlite pipeline steel. Combined with Voronoi polygon polycrystalline model and cohesive zone model, the effects of hydrogen atom number fractions, grain size and cementite termination surface on the mechanical properties of pipeline steel in a hydrogen environment were systematically analyzed. The results indicate that at the micro scale, with the increase of hydrogen atom number fractions, the critical interfacial tension of pipeline steel decreases obviously, which decreases by about 3.10% and 7.50% respectively at 2.5% and 5.0% hydrogen atom number fractions, and the fracture energy also shows a downward trend. The order of cementite termination surface according to crack resistance is C-Fe > C-C > Fe-Fe > Fe-C. At the meso-scale, the increase of hydrogen atom number fractions (5.0%) leads to a decrease of 8.39% in the critical stress intensity factor（K_IC） and an increase of 12.06% in the crack length. When the grain size is refined from 16 μm² to 4 μm², the K_IC increases by 31.38% and the crack length decreases by 17.30%. The influence of the termination surface is consistent with the microscopic results. This research provides a theoretical reference for the intrinsic safety evaluation and adaptability analysis of ferrite?pearlite pipeline steel in hydrogen environment.

The oxygen evolution reaction (OER) serves as the core step in water?splitting for hydrogen production,and its catalytic efficiency directly affects the economic conversion efficiency of hydrogen energy. In this work, a magnetic field?assisted one?step reduction method was used to successfully prepare amorphous metal boride nanobead catalysts. The phase composition and electrochemical properties of the catalysts were characterized, and the catalysts were applied to promote the OER catalytic reaction. The results show that among the various prepared metal borides, the cobalt?iron boride (CoFeB) directional nanobeads exhibited superior catalytic performance and remarkable stability, requiring an overpotential of only 330 mV at a current density of 10 mA/cm² with a Tafel slope of 82 mV/dec. The excellent electrocatalytic performance of the catalyst mainly stems from the synergistic effect of Co and Fe, which optimizes the electronic structure of active sites and significantly enhances catalytic efficiency. Furthermore, the effects of magnetic field strength and surfactant mass on the morphology and electrochemical behavior of CoFeB samples were systematically investigated, uncovering the strong correlation between catalytic activity, directional nanoparticle assembly, and structural features. The strategy proposed in this study is simple and scalable, providing a new approach for the design and development of high?efficiency and low?cost metal boride catalysts.

Efficient recovery of low-concentration hydrogen from industrial by?product tail gas is of great significance for energy utilization and low-carbon transition. This study employs a flow-through reactor packed with ReNi_4.35Co_0.4Mn_0.05Al_0.2 alloy, using a 25%H₂+75%N₂ gas mixture as the simulated feed, to systematically investigate the effects of the temperature of the circulating medium, inlet flow rate, and pressure on hydrogen separation and purification performance, with hydrogen utilization efficiency at a cumulative flow of 500 L as the core evaluation index. The results indicate that under the same circulating medium temperature and inlet gas pressure, hydrogen utilization efficiency decreases with increasing flow rate, with a more significant drop in the low to medium flow rate range; the influence of temperature shows a unimodal distribution, with 5 ℃ being optimal (balancing thermodynamics and kinetics); and increasing pressure enhances utilization efficiency, with the pressure-induced improvement more pronounced at low flow rates. The optimal process conditions are as follows: circulating medium temperature of 5 ℃, inlet gas pressure of 5 MPa, and inlet gas flow rate of 5 L/min. Under these conditions, the hydrogen utilization efficiency can reach 97.1%. The research content can provide theoretical and parameter basis for the recovery of low?concentration industrial by-product hydrogen via the metal hydride method.

Hydrogen permeation is a pivotal factor inducing hydrogen embrittlement (HE) in pipeline steels. Alloying presents an effective strategy for enhancing both the mechanical properties and HE resistance of these steels. In this review, the atomistic regulating mechanisms of alloying elements on critical steps of hydrogen permeation in pipeline steels are systematically summarized. The hydrogen permeation is considered to involve four critical steps: the adsorption and dissociation of hydrogen molecules, the adsorption and permeation of hydrogen atoms on the surface, the dissolution and migration in the bulk phase, and the segregation behavior at defects.The results show that single alloying element doping can effectively inhibit hydrogen permeation by inducing local lattice distortion, changing charge distribution, regulating bonding characteristics or increasing energy barriers. Furthermore, multi?elements synergic-doping and multi-principal element alloy systems exhibit more complex regulation mechanisms,and the synergistic effect of different elements can further enhance the inhibitory effect on hydrogen permeation. Future research can focus on the effect of multi-elements synergic-doping, the optimization and design of high-entropy alloys, hydrogen trapping under environments with complex defect structures and the development of multi-scale simulation methods, aiming to provide theoretical guidance and design strategies for advanced materials resistant to hydrogen embrittlement.

In the context of the shipping industry emission reduction target set by the International Maritime Organization and based on the current situation of carbon reduction in the shipping industry, this paper introduces the development history and emission reduction advantages of hydrogen powered ships, analyzes the hydrogen storage methods of hydrogen powered ships at home and abroad and the safety risks of hydrogen energy onboard, and compares the technical advantages and onboard feasibility of various Marine hydrogen storage methods. It is concluded that the hydrogen production technology of shipboard methanol steam reforming is of great significance to solve the hydrogen safety problem of hydrogen?powered ships. At last, the problems faced in developing hydrogen?powered ships with shipboard hydrogen production units are put forward.

As a new type of clean, carbon?free, sustainable and efficient energy source, hydrogen has great potential in the future energy mix. Hydrogen purification by pressure swing adsorption is the main separation technology for hydrogen production with high purity, low energy consumption and high degree of automation. In this paper the progress in research and application of pressure swing adsorption hydrogen production in theoretical simulation, process control optimization and adsorbent materials were critically reviewed, and the future development of pressure swing adsorption hydrogen production technology was prospected.

Establish a metal hydride reactor and test platform, and obtain the corresponding internal temperature and hydrogen absorption/desorption flow data of the reactor under different water bath temperatures, hydrogen release flow rates, and reactor structures (square, honeycomb, and no barriers) through experimental tests to determine The temperature field distribution trends and rules of different reactor internal structures are analyzed. The results show that the square structure reactor has the fastest internal temperature change rate and the best heat exchange effect. The comprehensive performance of the square structure reactor under different hydrogen absorption pressures and hydrogen release flow rates was further studied. The results show that when the inlet pressure is 2.0 MPa to 3.0 MPa, the hydrogen absorption amount and hydrogen absorption rate of the alloy material can be significantly increased; when the hydrogen release flow rate is less than 3.2 L/min, more than 85% of hydrogen can be released. The research results can provide technical guidance for modular and systematic design.

In the methanol autothermal reforming reaction, the required heat is provided by the methanol oxidation reaction, so the activity of the methanol oxidation catalyst directly affects the yield of hydrogen. Pt/γ?Al₂O₃ catalysts have attracted wide attention because of its high reactivity, but their stability is poor, and the Pt activity center is easy to agglomerate. In order to solve the above problems, Pt/γ?Al₂O₃ catalysts were prepared by rotary microemulsion, and Pt/γ?Al₂O₃ catalysts were characterized by BET, XRD and other methods, and the effects of cyclohexane mass fraction, mass ratio of PEG?600 and n?butanol on the oxidation activity of methanol were investigated. The results show that the microemulsion method could improve the dispersion and utilization rate of the active components. By changing the mass fraction of cyclohexane and the mass ratio of PEG?600 to n?butanol, the active component Pt can be uniformly and firmly loaded on γ?Al₂O₃, and the sintering resistance of the catalyst can be improved. The Pt/γ?Al₂O₃ catalyst prepared under the condition of cyclohexane mass fraction of 50% and the mass ratio of PEG?600 to n?butanol is 3∶7, and the catalytic activity of methanol oxidation can reach 88%.

Catalysts CuCe?OH and CuCe?CO₃ were prepared by hydrothermal method using KOH and K₂CO₃ as precipitating agents. The catalyst was characterized by XRD, BET, H₂?TPR and TG?DTA, and its CO catalytic oxidation performance was evaluated by a fixed bed reactor. The results show that the type of precipitator not only has a great influence on the texture properties of the catalyst, but also determines whether the CuCe catalyst without heterocrystalline phase can be successfully prepared. The specific surface areas of CuCe?OH and CuCe?CO₃ catalysts were 96.5 m²/g and 17.3 m²/g, respectively. Under the evaluation conditions of 60 000 mL/（g·h）, CO volume fraction of 0.6%, O₂ volume fraction of 1.5%, Ar volume fraction of 97.9%, CuCe?OH catalyst showed good catalytic activity, and CO conversion reached 99.0% at 140 ℃.