{
  "abstract": "Controlling electrocatalytic selectivity requires not only tuning catalyst composition but also controlling the interfacial states that emerge during operation. Here, using bulk Pd as a model system for electrochemical CO 2 reduction reaction (CO 2 RR), we show that poor steady-state formate production emerges from time-dependent evolution of the electrochemical interface. Pd initially exhibits appreciable formate activity but rapidly accumulates strongly bound CO and evolves toward a CO-rich, formate-inactive state. Although substantial sorbed H persists during this evolution, its oxidation shifts to increasingly positive potentials with increasing CO coverage, indicating reduced electrochemical accessibility and reactivity of H at the CO-covered interface. Density functional theory shows that CO-rich configurations are thermodynamically favored under cathodic conditions, while increasing CO coverage destabilizes early intermediates of both the formate and CO pathways. Dynamic potential modulation temporally separates surface-state preparation from catalytic turnover: anodic excursions remove accumulated CO, and subsequent cathodic polarization repeatedly accesses a CO-depleted state that is not thermodynamically favored at the reaction potential. This strategy produces an approximately 230-fold enhancement in formate partial current density relative to static operation. Within this dynamically accessible low-CO regime, formate activity further correlates with sorbed-H availability. These results reveal a hierarchical interfacial control in which CO coverage gates pathway accessibility while hydrogen availability modulates formate activity, demonstrating how temporal control can access catalytic states and reaction pathways hidden under steady-state operation.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry",
    "University of Texas at Austin",
    "Center for Electrochemistry",
    "Texas Materials Institute"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Hyein Lee",
      "orcid": "0009-0007-4658-9630"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Satoshi Ohtsuka"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Wenrui Chai"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Tamilselvi Gurusamy"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Johan I. Martinez"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Graeme Henkelman"
    },
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Hang Ren"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1m1pttdj7v50k.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008360/v1",
  "fulltext_url": null,
  "id": "1m1pttdj7v50k",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008360/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2105|CO2 Reduction Techniques and Catalysts"
    ]
  ],
  "openalex": "W7211875385",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008360/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-06",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/1m1pttdj7v50k.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008360",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008360/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "Temporal Programming of Interfacial States Reveals a Hidden Formate Pathway from CO2 Reduction on Palladium",
  "title_text": "Temporal Programming of Interfacial States Reveals a Hidden Formate Pathway from CO2 Reduction on Palladium",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:17Z",
  "url": "https://research.draconitic.com/paper/1m1pttdj7v50k",
  "venue": "ChemRxiv",
  "versions": []
}