{
  "abstract": "Ga is a key component of commercial propane dehydrogenation (PDH) catalysts. The regeneration of those catalysts involves oxidation and reduction cycles, the latter typically under H2 at about 550–650 °C. However, the structural evolution of Ga3+ sites under those strongly reducing conditions is underexplored. Here, we monitored the transformations of Ga3+ sites dispersed on a SiO2 support under H2 at 650 °C. The results show that this treatment generates metastable ºSiOGa1+ sites that disproportionate to Ga0 and Ga3+ sites. The formed Ga0 species react with surface silanols, regenerating ºSiOGa1+ sites, and with water formed during the reduction of Ga3+ to Ga1+, ultimately yielding large crystalline particles of k-Ga2O3. In addition, an overall loss of Ga from the catalyst is observed and attributed to the formation of Ga0 and volatile Ga2O. The Lewis acidity of dispersed Ga3+ decreases when it interacts with weakly Lewis-basic ºSiOGa1+ motifs. All of these processes associated with ºSiOGa1+ sites decrease the number of dispersed Ga3+ sites and are therefore detrimental for PDH activity, except that dispersed Ga3+ sites formed from disproportionation of ºSiOGa1+ sites likely have increased strain, beneficial for PDH activity. While H2 treatment alone has a negative impact on the catalyst’s PDH activity and propene selectivity, an oxidative air treatment of the reduced catalyst terminates disproportionation dynamics by oxidizing Ga0 and increases the Ga-based activity relative to both the reduced and fresh catalysts. These findings suggest that the disproportionation of Ga1+ species under an H2 atmosphere appreciably affects gallium speciation, loading, and catalytic performance.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Mechanical and Process Engineering",
    "ETH Zürich",
    "RAS",
    "Department of Chemical Sciences",
    "University of Padova",
    "Centre de RMN à hauts champs de Lyon",
    "UMR 5082 (CNRS, ENS Lyon, Université Lyon",
    "Department of Chemistry and Applied Biosciences",
    "Cochin University of Science and Technology",
    "Departament de Química",
    "Universitat Autònoma de Barcelona",
    "CEMHTI UPR3079",
    "Université d’Orléans"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 18,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Zixuan Chen"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Melis Yarar"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Nora K. Zimmerli"
    },
    {
      "affs": [
        2
      ],
      "name": "Alexander I. Serykh"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Mattia Cattelan"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Stefano Agnoli"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Agnieszka Kierzkowska"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Yi-Hsuan Wu"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "David Gajan"
    },
    {
      "affs": [
        7,
        1
      ],
      "name": "Alexander V. Yakimov"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Marcel Janák"
    },
    {
      "affs": [
        8
      ],
      "name": "Praveen Chandramathy Surendran"
    },
    {
      "affs": [
        9,
        10
      ],
      "name": "Aleix Comas-Vives"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Christophe Copéret"
    },
    {
      "affs": [
        11,
        12
      ],
      "name": "Pierre Florian"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Paula M. Abdala"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Christoph R. Müller"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Alexey Fedorov",
      "orcid": "0000-0001-9814-6726"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8bjek01nnszpb.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15011003/v1",
  "fulltext_url": null,
  "id": "8bjek01nnszpb",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15011003/v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1503|Catalysis and Oxidation Reactions"
    ]
  ],
  "openalex": "W7223682654",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15011003/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-25",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/8bjek01nnszpb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:26Z",
      "native_id": "10.26434/chemrxiv.15011003",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15011003/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1503|Catalysis and Oxidation Reactions",
      "subfield": "catalysis"
    }
  ],
  "title": "Dynamic Disproportionation Shapes Ga Sites in Silica-Supported Propane Dehydrogenation Catalysts",
  "title_text": "Dynamic Disproportionation Shapes Ga Sites in Silica-Supported Propane Dehydrogenation Catalysts",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:26Z",
  "url": "https://research.draconitic.com/paper/8bjek01nnszpb",
  "venue": "ChemRxiv",
  "versions": []
}