{
  "abstract": "Lateral interactions between co–adsorbed species can produce non-random spatial organization that governs the availability of reactive motifs relevant to catalytic behavior. For CO* and H* co–adsorbed on Pt(111), these interactions determine how the two species distribute across the surface and therefore which local CO*–H* configurations are available under reaction conditions. In this work, we combine density functional theory, cluster expansions, and grand canonical Monte Carlo simulations to determine how CO* and H* organize on Pt(111), and subsequently use electronic surface charge as a controlled perturbation to examine how this organization responds to changes in the underlying energetics. On neutral Pt(111), CO*–H* first-nearest-neighbor interactions are strongly repulsive (0.42 eV), CO*–CO* first-nearest-neighbor interactions are moderately repulsive (0.12 eV), and H*–H* interactions are comparatively weak. These interactions cause CO* to nucleate into islands that grow and coalesce with increasing CO* coverage, while H* preferentially occupies regions outside CO*-rich domains. Consequently, the abundance of CO*–H* nearest-neighbor configurations varies non-monotonically with CO* coverage, reaching a maximum at intermediate coverage before decreasing as CO* islands grow and the adsorbates become increasingly segregated. Positive surface charge strengthens CO* adsorption but also increases CO*–CO* repulsion, producing higher CO* coverages, a broader distribution of CO* island sizes, and larger low-coverage regions between islands where H* can adsorb away from CO*. This suppresses CO*–H* nearest-neighbor configurations relative to the neutral surface. Negative charging weakens CO* adsorption, producing lower CO* coverages, higher H* coverages, and less consolidated CO* islands, thereby increasing the prevalence of mixed CO*–H* local environments. At intermediate CO* coverage, CO* islands enter a regime of accelerated growth and coalescence that coincides with a shallow plateau in H* coverage. This coincidence suggests that the onset of CO* island coalescence is accompanied by a reorganization of the co-adsorbed layer. Further, it illustrates the strong influence of lateral interactions on the formation of potentially reactive motifs, highlighting how they become influential in determining catalytic reactivity.",
  "abstract_shown": true,
  "affiliations": [
    "William G. Lowrie Department of Chemical & Biomolecular Engineering, Ohio State University, 151 W. Woodruff Rd., Columbus, Ohio, 43210",
    "Center for Programmable Energy Catalysis",
    "Minnesota",
    "Department of Chemical Engineering",
    "University of California Santa Barbara"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Sifat Hossain"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Venkata Rohit Punyapu"
    },
    {
      "affs": [
        1,
        2,
        3,
        4
      ],
      "name": "Phillip Christopher"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Rachel B. Getman",
      "orcid": "0000-0003-0755-0534"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0y2za6mvzzvrw.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15009043/v1",
  "fulltext_url": null,
  "id": "0y2za6mvzzvrw",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009043/v1",
  "language": null,
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2505|Catalytic Processes in Materials Science"
    ]
  ],
  "openalex": "W7213540204",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15009043/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-18",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/0y2za6mvzzvrw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:19Z",
      "native_id": "10.26434/chemrxiv.15009043",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009043/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Catalytic Processes in Materials Science",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Coverages and Configurations of CO* and H* on Pt(111) under Realistic Reaction Conditions",
  "title_text": "Coverages and Configurations of CO* and H* on Pt(111) under Realistic Reaction Conditions",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:19Z",
  "url": "https://research.draconitic.com/paper/0y2za6mvzzvrw",
  "venue": "ChemRxiv",
  "versions": []
}