Hydrogen via Co-Electrolysis of Water and CO₂: Challenge or Solution for Industrial Decarbonization?

The paper investigates the potential of co-electrolysis as a viable pathway for hydrogen production and industrial decarbonization, expanding on previous studies on water electrolysis. The analysis adopts a general and critical perspective, aiming to assess the realistic scope of this technology in light of current energy and environmental needs. Although co-electrolysis theoretically offers improved efficiency by simultaneously converting H₂O and CO₂ into syngas, the practical advantages are difficult to consolidate. The study highlights that the energetic margins of the process remain relatively narrow, and that several key aspects, including system irreversibilities and the limited availability of CO₂ in many contexts, significantly constrain its applicability. Despite the growing interest and promising technological developments, co-electrolysis still faces substantial challenges before it can be implemented on a scale. The findings suggest that its success will depend on targeted integration strategies, advanced thermal management, and favorable boundary conditions rather than on the intrinsic efficiency of the process alone. However, there are specific sectors where assessing the implementation potential of co-electrolysis could be of interest, a perspective this paper aims to explore.