{
  "abstract": "The decisive challenge in nitrate-to-ammonia electrosynthesis is not simply supplying electrons, but ensuring that successive nitrogen intermediates remain chemically convertible. Here, we establish a molecular strategy that differentiates framework-derived electronic character from metal-directed reaction selectivity through TU-420, a crystalline covalent organic framework integrating electron-donating tetrathiafulvalene and electron-accepting, metal-coordinating bipyridine units. Electronic-structure analysis identifies complementary donor-associated and acceptor-like states, while Xray absorption spectroscopy reveals distinct approximately six-coordinate Fe–O/N and four-coordinate Cu–O/N environments within the conserved architecture. Remarkably, TU-420-Fe achieves 98.1% ammonia Faradaic efficiency at −0.60 V versus the reversible hydrogen electrode and an ammonia production rate of 4.33 mg h-1 cm-2 at −0.80 V, whereas TU-420-Cu exhibits substantially lower selectivity despite its stronger cathodic response. Isotope-labeling experiments establish nitrate as the nitrogen source, while in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy, Raman spectroscopy, and differential electrochemical mass spectrometry reveal signatures consistent with evolving nitrogen–oxygen and hydrogenated nitrogen species. Density functional theory identifies the mechanistic distinction: Fe supports a favorable *NHO-mediated reduction sequence with a maximum uphill free-energy increment of 0.30 eV, while substantially alleviating the energetic penalty associated with the competing *NOH-mediated route relative to Cu. These findings identify the energetic fate of partially reduced nitrogen, rather than electron consumption alone, as a determinant of ammonia selectivity and establish electronically differentiated covalent architectures as platforms for programming metal-dependent multielectron catalysis.",
  "abstract_shown": true,
  "affiliations": [
    "Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Japan, 980-8577",
    "Department of Physics",
    "SRM University–AP"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Tsukasa Irie"
    },
    {
      "affs": [
        0
      ],
      "name": "Hayato Orui"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Sourav Ghosh"
    },
    {
      "affs": [
        0
      ],
      "name": "Riki Nakatani"
    },
    {
      "affs": [
        0
      ],
      "name": "Chaoqi Chen"
    },
    {
      "affs": [
        0
      ],
      "name": "Saranya Sasikumar"
    },
    {
      "affs": [
        0
      ],
      "name": "Tokuhisa Kawawaki"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Ranjit Thapa"
    },
    {
      "affs": [
        0
      ],
      "name": "Saikat Das"
    },
    {
      "affs": [
        0
      ],
      "name": "Yuichi Negishi",
      "orcid": "0000-0003-3965-1399"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ewymje2r4v5tz.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010463/v1",
  "fulltext_url": null,
  "id": "ewymje2r4v5tz",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010463/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",
      "1503|Ammonia Synthesis and Nitrogen Reduction"
    ]
  ],
  "openalex": "W7221753335",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010463/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/ewymje2r4v5tz.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15010463",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010463/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1503|Ammonia Synthesis and Nitrogen Reduction",
      "subfield": "catalysis"
    }
  ],
  "title": "Charge Donated by the Framework, Reactivity Expressed at the Metal: Tetrathiafulvalene-Programmed Nitrate Reduction to Ammonia",
  "title_text": "Charge Donated by the Framework, Reactivity Expressed at the Metal: Tetrathiafulvalene-Programmed Nitrate Reduction to Ammonia",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/ewymje2r4v5tz",
  "venue": "ChemRxiv",
  "versions": []
}