CC BY 4.0 UnportedSchuster, JürgenUkrainczyk, NevenKoenders, EddieStöckl, Markus2025-08-052025-08-052023https://oa.tib.eu/renate/handle/123456789/20696https://doi.org/10.34657/19713To achieve a successful transition to a sustainable carbon and energy management, it is essential to both reduce CO2 emissions and develop new technologies that utilize CO2 as a starting substrate. In this study, we demonstrate for the first-time the functionalization of geopolymer binder (GP) with Sn for electrochemical CO2 reduction (eCO2RR) to formate. By substituting cement with Sn-GP, we have merged CO2 utilisation and emission reduction. Using a simple mixing procedure, we were able to obtain a pourable mortar containing 5 vol. % Sn-powder. After hardening, the Sn-GP electrodes were characterized for their mechanical and CO2 electrolysis performance. In 10 h electrolyses, formate concentrations were as high as 22.7±0.9 mmol L−1 with a corresponding current efficiency of 14.0±0.5 % at a current density of 20 mA cm−2. Our study demonstrates the successful design of GP-electrodes as a new class of hybrid materials that connect eCO2RR and construction materials.enghttps://creativecommons.org/licenses/by/4.0/500 | Naturwissenschaften::540 | Chemieelectrochemical CO2 reductionformategeopolymer electrodeSn-functionalizationnew electrode materialArticle