Dimensionless modeling of the electro‐fluid interactions in DBD plasma reactors for CO ₂ splitting

Non‐thermal dielectric barrier discharge (DBD) reactors are intensively studied for CO 2 splitting, yet the absence of proper scaling approaches continues to hinder predictive design and scale‐up. Here, we establish a unified electro‐chemo‐fluid framework that rationalizes reactor behavior across geometries, discharge lengths, and flow rates by integrating Lissajous diagnostics, performance analysis, and dimensionless modeling. Electrical observables scale with plasma power and reactor architecture, whereas CO 2 conversion and energy efficiency are dictated by gas throughput relative to the specific energy input (SEI), demonstrating that performance cannot be inferred from the discharge state alone. Instead, it emerges from the coupled action of electro‐fluid forcing and chemo‐fluid transport‐reaction processes. This interplay is captured through Masuda, Reynolds, and Damköhler numbers, which collapse both present and literature data onto a single monotonic trend. The proposed framework enables predictive comparison, design, and scale‐up of DBD reactors beyond empirical metrics.