Hydrogen

Hydrogen has antioxidant and anti-inflammatory properties that may attenuate perioperative stress responses. However, its clinical impact on postoperative recovery remains unclear. This randomized, double-blind, placebo-controlled trial evaluated whether perioperative hydrogen inhalation improves early recovery after hepatectomy. Sixty-eight patients undergoing elective hepatectomy were randomized (1:1) to receive 5% hydrogen gas or placebo air via nasal cannula from postoperative day (POD) 1 to POD7. The primary endpoint was the total Quality of Recovery-40 (QoR-40) score on POD3, analyzed at α = 0.2 with 80% confidence intervals in accordance with the pre-specified statistical analysis plan. Secondary and exploratory outcomes, analyzed at α = 0.05, included postoperative liver function, oxidative stress markers, and QoR-40 subdomain scores. Analyses were performed in the modified intention-to-treat population using the Mann–Whitney U test. Sixty-four patients (hydrogen, n = 31; placebo, n = 33) were analyzed. At POD3, the median QoR-40 score was 192.0 (184.0–198.0) vs. 163.0 (140.0–190.0) (p < 0.001), indicating significantly better early recovery in the hydrogen group. As supportive findings, prothrombin activity was higher with hydrogen (85.0% vs. 76.2%, p = 0.005), and QoR-40 subdomain analysis showed significantly higher emotions and physical independence scores, whereas comfort, pain, and patient support domains showed no difference. No other between-group differences were observed in biochemical parameters or urinary 8-OHdG levels. Perioperative hydrogen inhalation significantly improved early postoperative recovery after hepatectomy, primarily through psychophysical domains of well-being. These findings suggest that hydrogen may selectively enhance emotional stability and functional independence during the early recovery phase.

The composite material MgH₂-EEWNi-Cr (20 wt. %) with a hydrogen content of 5.2 ± 0.1 wt.% is characterized by improved hydrogen interaction properties compared to the original MgH₂. The dissociation of the material occurs in three temperature ranges (86–117, 152–162, and 281–351 °C), associated with a complex of effects consisting of changes in the specific surface area of the material, alterations in the crystal lattice during ball milling, and changes in the electronic structure in the presence of a Ni–Cr catalyst, based on first-principles calculations. The decrease in desorption activation energy (E_d = 65–96 ± 1 kJ/mol, ΔE_d = 59–90 kJ/mol) is due to the catalytic effect of N–Cr, leading to a faster decomposition of the hydride phase. Based on the results of ab initio calculations, Ni–Cr on the MgH₂ surface leads to a significant decrease in hydrogen binding energy (ΔE_b = 60%) compared to pure magnesium hydride due to the formation of Ni–H and Cr–H covalent bonds, which reduces the degree of H–Mg ionic bonding. The results obtained allow us to expand our understanding of the mechanisms of hydrogen interaction with storage materials and the possibility of using these as mobile hydrogen storage and transportation materials.

The use of liquid hydrogen (LH₂) as an energy carrier is gaining traction across sectors such as aerospace, maritime, and large-scale energy storage due to its high gravimetric energy density and low environmental impact. However, the cryogenic nature of LH₂, with storage temperatures near 20 K, poses significant thermodynamic and safety challenges. This review consolidates the current state of modelling approaches used to simulate LH₂ behaviour during storage and transfer operations, with a focus on improving operational efficiency and safety. The review categorizes the literature into two primary domains: (1) thermodynamic behaviour within storage tanks and (2) multi-phase flow dynamics in storage and transfer systems. Within these domains, it covers a variety of phenomena. Particular attention is given to the role of heat ingress in driving self-pressurization and boil-off gas (BoG) formation, which significantly influence storage performance and safety mechanisms. Eighty-one studies published over six decades were analyzed, encompassing a diverse range of modelling approaches. The reviewed literature revealed significant methodological variety, including general analytical models, lumped-parameter models (0D/1D), empirical and semi-empirical models, computational fluid dynamics (CFD) models (2D/3D), machine learning (ML) and artificial neural network (ANN) models, and numerical multidisciplinary simulation models. The review evaluates the validation status of each model and identifies persistent research gaps. By mapping current modelling efforts and their limitations, this review highlights opportunities for enhancing the accuracy and applicability of LH₂ simulations. Improved modelling tools are essential to support the design of inherently safe, reliable, and efficient hydrogen infrastructure in a decarbonized energy landscape.