{"paper":{"title":"Magnesium-graphene interphase boundaries created by high-pressure torsion enhance hydrogen storage kinetics:Mechanisms and significance of activation energy and frequency factor","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"Magnesium-graphene interphase boundaries created by high-pressure torsion increase the frequency factor for hydrogen desorption while activation energy stays fixed at 145 kJ/mol.","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"Anthony Alhayek, Baran Bidyut Saha, Kaveh Edalati, Marc Novelli, Md. Amirul Islam, Payam Edalati, Runchen Zhou, Shivam Dangwal, Thierry Grosdidier","submitted_at":"2026-05-13T08:42:41Z","abstract_excerpt":"A strategy to overcome sluggish hydrogenation/dehydrogenation of magnesium is demonstrated by creating magnesium-graphene interphase boundaries via high-pressure torsion (HPT). HPT reduces the grain size of pure magnesium from 1 mm to 850 nm, with 70% of grain boundaries having high misorientation angles. Graphene addition leads to even finer grain sizes of 10-500 nm with a bimodal morphology. The magnesium-graphene composites exhibit superior kinetics at 623 K while maintaining high air resistance. Kinetic modeling reveals that the rate-controlling mechanism transits from interfacial reaction"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Kinetic modeling reveals that the rate-controlling mechanism transits from interfacial reaction in coarse-grained magnesium to atomic diffusion in magnesium-graphene nanocomposites. Kissinger analysis shows that the activation energy for hydrogen desorption remains unchanged at 145 +/- 2 kJ/mol, regardless of the presence of grain or interphase boundaries. However, the frequency factor increases with the generation of interfaces, which serve as sites for hydrogen diffusion and heterogeneous metal/hydride nucleation.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the increase in frequency factor and the shift in rate-controlling mechanism are caused specifically by the magnesium-graphene interphase boundaries rather than other processing-induced changes such as overall grain refinement or residual strain.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Magnesium-graphene nanocomposites made by high-pressure torsion show faster hydrogen storage kinetics because interfaces increase the frequency factor for diffusion and nucleation, while activation energy stays fixed at 145 kJ/mol.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Magnesium-graphene interphase boundaries created by high-pressure torsion increase the frequency factor for hydrogen desorption while activation energy stays fixed at 145 kJ/mol.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"6b6852b4673eaf4d3796d2758d59680bca4964849aed86303724cc0be422d294"},"source":{"id":"2605.13184","kind":"arxiv","version":1},"verdict":{"id":"1dc2fd1d-3f6a-4457-bc19-25427fe8b590","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T18:59:26.060630Z","strongest_claim":"Kinetic modeling reveals that the rate-controlling mechanism transits from interfacial reaction in coarse-grained magnesium to atomic diffusion in magnesium-graphene nanocomposites. Kissinger analysis shows that the activation energy for hydrogen desorption remains unchanged at 145 +/- 2 kJ/mol, regardless of the presence of grain or interphase boundaries. However, the frequency factor increases with the generation of interfaces, which serve as sites for hydrogen diffusion and heterogeneous metal/hydride nucleation.","one_line_summary":"Magnesium-graphene nanocomposites made by high-pressure torsion show faster hydrogen storage kinetics because interfaces increase the frequency factor for diffusion and nucleation, while activation energy stays fixed at 145 kJ/mol.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the increase in frequency factor and the shift in rate-controlling mechanism are caused specifically by the magnesium-graphene interphase boundaries rather than other processing-induced changes such as overall grain refinement or residual strain.","pith_extraction_headline":"Magnesium-graphene interphase boundaries created by high-pressure torsion increase the frequency factor for hydrogen desorption while activation energy stays fixed at 145 kJ/mol."},"references":{"count":63,"sample":[{"doi":"","year":2021,"title":"Hydrogen energy systems: a critical review of technologies, applications, trends and challenges","work_id":"15325d6f-d2bb-4b61-ac0b-a6caf7c520db","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2020,"title":"Materials for hydrogen -based energy storage - past, recent progress and future outlook","work_id":"e5058047-0cce-431d-9e88-2825aa68b91a","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2019,"title":"Application of hydrides in hydrogen storage and compression: achievements, outlook and perspectives","work_id":"22d25f6e-d515-4684-8ea5-6ea9fe39ffff","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2019,"title":"Magnesium based materials for hydrogen based energy storage: past, present and future","work_id":"04c04763-5cff-41c6-9f60-a8a14222057e","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2022,"title":"Magnesium - and intermetallic alloys -based hydrides for energy storage: modelling, synthesis and properties","work_id":"3db15abc-6174-44a3-b514-3fb58546e89d","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":63,"snapshot_sha256":"6e16c5786e5a6add413e71eeb1efd7e2f89d48c33cb1cae9209990146ad29808","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}