Conductivity-Based Rapid Characterization of Porous Solid-State Electrolyte Reactors

Solid-state electrolyte (SSE) reactors represent a promising platform for carbon capture and utilization (CCU), particularly due to their ability to directly convert CO2 to high-purity liquid products. However, conventional nuclear magnetic resonance (NMR) and chromatography techniques for performance characterization are often time-consuming, instrument-intensive, and procedurally complex. This study presents a rapid characterization method that determines Faradaic efficiency (FE) by measuring the conductivity of the extraction solution from the SSE reactors and applying an empirical correlation to estimate formic acid concentration. The method exhibits strong robustness across a wide range of reactor configurations and components, including variations in separator materials, gas diffusion electrode (GDE) properties, anode types, SSE compositions, and electrocatalysts. Comparative analysis with high-performance liquid chromatography (HPLC) confirms the reliability of the conductivity-based method, yielding an average relative error of 6.1% in concentration and FE. By enabling rapid and accurate performance assessment, this method supports the efficient screening of SSE reactor designs and operating conditions, thereby accelerating the development of sustainable CO2 valorization technologies.