Decoupling the Size and Loading Effects in Silver Nanoparticles for Efficient Paired Carbon Dioxide and Formaldehyde Electrolysis

Tandava VS, Große C, Bagchi D, Zhu Z, Ghosh S, Hausmann JN, Walter C, Anzorena RS, Jimenez CE, Cobos-Becerra YL, Fletcher JC, Sontheimer T, Schwarze M, Dau H, Driess M, Bär M, Menezes PW (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Advanced Functional Materials Wiley-VCH Verlag

DOI: 10.1002/adfm.78365

Abstract

Successful integration of silver nanoparticles (Ag NPs) towards highly selective electrochemical CO2 reduction to carbon monoxide (CO) is often hindered by size-dependent selectivity trade-offs in Ag NPs and by inefficient full-cell operation. Here, we systematically investigate ligand-mediated colloidal synthesis of (quasi) monodisperse Ag NPs (6–15 nm) and evaluate them in a gas-diffusion-electrode-based flow-cell architecture, revealing a pronounced size-dependent activity volcano. By incorporating a non-catalytic carbon support, we demonstrate that an optimized Ag-to-carbon (Ag/C) loading, specifically 20% with 10 nm Ag NPs, achieves nearly 100% Faradaic Efficiency (FE) for CO at −100 mA·cm−2, significantly outperforming other particle sizes and a commercial Ag catalyst at similar loadings. In situ Raman spectroscopy reveals a substantial role of Ag/C interactions in enhancing the affinity toward the *COOH intermediates, thereby promoting high CO2-to-CO selectivity. Post-electrolysis, X-ray photoelectron spectroscopy (XPS) further indicates the electronic and chemical structural stability of the optimized Ag/C, which retains the metallic Ag0 state. Finally, we demonstrate the bifunctional nature of Ag/C electrodes by pairing CO2 and formaldehyde electrolysis, enabling simultaneous CO generation at the cathode and formate (HCOO−) with hydrogen (H2) at the anode at reduced cell potentials. This work highlights an energy-efficient paired electrosynthesis strategy supporting the progress toward a circular carbon economy.

Authors with CRIS profile

Marcus Bär

Involved external institutions

Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) DE Germany (DE) Technische Universität Berlin DE Germany (DE) Freie Universität Berlin DE Germany (DE) University of Cape Town (UCT) ZA South Africa (ZA)

How to cite

APA:

Tandava, V.S., Große, C., Bagchi, D., Zhu, Z., Ghosh, S., Hausmann, J.N.,... Menezes, P.W. (2026). Decoupling the Size and Loading Effects in Silver Nanoparticles for Efficient Paired Carbon Dioxide and Formaldehyde Electrolysis. Advanced Functional Materials. https://doi.org/10.1002/adfm.78365

MLA:

Tandava, Venkata S.R.K., et al. "Decoupling the Size and Loading Effects in Silver Nanoparticles for Efficient Paired Carbon Dioxide and Formaldehyde Electrolysis." Advanced Functional Materials (2026).

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