{
  "abstract": "Electrochemical interfaces feature dynamically evolving local reactant distributions that strongly influence catalytic behavior. In electrochemical CO 2 reduction (CO 2 RR), the low solubility and limited diffusion of CO 2 generate highly non-uniform local reaction environments near electrochemical interfaces. However, the actual spatial distribution of dissolved CO 2 within the interfacial structure under operating conditions remains poorly understood due to limited experimental visualization methods that probe interfacial structure. Here, we introduce an in situ ratiometric fluorescent labeling strategy with a CO 2 -sensitive chemosensor to directly visualize dissolved CO 2 distributions during CO 2 RR. Using a pyrene-modified fluorescent chemosensor, we directly visualize the spatial distribution and dynamic evolution of local dissolved CO 2 concentrations near electrochemical interfaces. The measurements reveal pronounced spatial heterogeneity in the CO 2 RR microenvironment, dynamic evolution of gas-liquid-solid interfaces, and unexpectedly strong local CO 2 enrichment. Dissolved CO 2 concentrations near the interface approached ~84.4 ± 27.5 mM. Beyond CO 2 RR, this work establishes fluorescent labeling as a general operando visualization strategy for probing local reactant distributions and interfacial mass transport processes in electrochemical systems.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 1117574",
    "Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585",
    "Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117576"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Caiwei Zhang"
    },
    {
      "affs": [
        1
      ],
      "name": "Jianye Hong"
    },
    {
      "affs": [
        2
      ],
      "name": "Ge Yan"
    },
    {
      "affs": [
        0
      ],
      "name": "Chaolong Wei"
    },
    {
      "affs": [
        0
      ],
      "name": "Guangxin Sun"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Andrew B. Wong",
      "orcid": "0000-0002-0731-1931"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dy4rp6j7k1p2t.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010616/v1",
  "fulltext_url": null,
  "id": "dy4rp6j7k1p2t",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010616/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": "W7223133146",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-16",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/dy4rp6j7k1p2t.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15010616",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010616/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "In Situ Mapping of Aqueous CO2 during the Electrochemical CO2 Reduction Reaction",
  "title_text": "In Situ Mapping of Aqueous CO2 during the Electrochemical CO2 Reduction Reaction",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/dy4rp6j7k1p2t",
  "venue": "ChemRxiv",
  "versions": []
}