Authors: Ameen A. Al‐Muntaser | Muneer A. Suwaid | Il’dar R. Il’yasov | Shadi A. Saeed | Ismail Khelil | Xiaodong Zhou | Elina B. Isaeva | Anastasia N. Mikhailova | Mikhail A. Varfolomeev | Ahmed S. Al‐Fatesh | Lokesh Joshi | Danis K. Nurgaliev
Source:  (article, 2025-05-12)
Field: Materials Science — Materials Chemistry

Toward Hydrogen Storage and Transportation Over Long Distances via Dehydrogenation of the Cyclo-Based Liquid Organic Hydrogen Carrier in the Presence of the PdO/Al2O3 Abstract Amid the global transition to clean and resource-efficient energy, hydrogen is seen as one of the most promising energy carriers of the future. This research investigates the potential of Methylcyclohexane (MCH) as a liquid organic hydrogen carrier (LOHC) for hydrogen storage and transportation. The study focuses on optimizing the catalytic dehydrogenation process using PdO/Al2O3, aiming to improve hydrogen release efficiency under mild reaction conditions while ensuring high conversion rates. The experiments were conducted in a high-temperature, high-pressure batch reactor (100 mL) at 300°C under 1 bar of inert nitrogen atmosphere. Six reactions were performed: three without catalysts and three with PdO/Al2O3 catalyst (0.5 g). Reaction times of 3, 6, and 9 hours were evaluated. Product analysis, including gaseous and liquid phases, was conducted using GC and GC-MS techniques. Catalyst optimization involved the determination of the reduction temperature and active phase dispersion. Catalytic dehydrogenation using PdO/Al2O3 significantly enhanced the conversion of Methylcyclohexane (MCH), achieving rates ranging from 8.12% to 67.03%, depending on the reaction time (3, 6, and 9 hours). In contrast, non-catalytic experiments yielded minimal MCH conversion, underscoring the catalytic system’s critical role. Hydrogen release was confirmed via GC analysis, with a clear linear relationship between extended reaction times and increased conversion rates. To further understand the catalyst’s behavior, its structural and morphological properties were examined using X-ray Diffraction (XRD), revealing highly dispersed Pd nanoparticles on the Al2O3 support and confirming the crystalline phases present. Catalyst optimization included fine-tuning the reduction temperature, which significantly improved catalytic activity and hydrogen evolution kinetics. Additionally, the selectivity of the process was evaluated, with GC-MS analysis identifying key by-products and ensuring minimal hydrocarbon cracking. The selectivity towards hydrogen generation remained high, emphasizing the catalyst’s suitability for efficient hydrogen release. This study demonstrates the viability of MCH as a liquid organic hydrogen carrier (LOHC) under mild conditions, highlighting the developed PdO/Al2O3 system’s potential for scalable, sustainable hydrogen storage and transportation solutions in industrial applications. This paper presents novel insights into optimizing the catalytic dehydrogenation of Methylcyclohexane (MCH) using PdO/Al2O3, specifically addressing the balance between conversion efficiency and process selectivity. It introduces a comprehensive evaluation of catalyst performance, including structural characterization and reaction pathway analysis. These findings offer practical guidelines for engineers working on sustainable hydrogen storage and transportation, advancing the development of efficient liquid organic hydrogen carrier (LOHC) systems for industrial applications. Dehydrogenation ; Hydrogen storage ; Hydrogen ; Liquid hydrogen ; Materials science ; Chemistry ; Organic chemistry ; Catalysis Hydrogen Storage and Materials ; Hybrid Renewable Energy Systems ; Fuel Cells and Related Materials