Abstract: A membraneless electrolysis cell, which includes a solid body, the solid body having a central cavity, two housings, at least one secondary cavity, at least one duct for providing a material, two ducts for admitting two electrolyte flows, and at least one supply duct. The cell configuration allows a material, in particular a reagent, to be fed selectively to the anode or cathode, separate from the electrolyte flow.

Abstract: The present invention concerns a flow cell electrolyzer (1) to electrochemically reduce reagent gas CO2 into gaseous CO, with an anodic compartment comprising an anode (2) with a current collector, and on the current collector, at least a catalyst to electrochemically oxidize H2O to O2, an anodic electrolyte solution (3) at a controlled flow rate Qa, comprising: a solvent, and an anodic electrolyte, the solvent being water at neutral or basic pH; a cathodic compartment comprising a cathodic electrolyte solution (6), at a controlled flow rate Qc, comprising: the solvent, and a cathodic electrolyte, the solvent being water at neutral or basic pH, a gas diffusion porous cathode (9) which comprises, on a gas diffusion porous current cathode collector which is electrochemically inert, at least a molecular catalyst on a surface S to electrochemically reduce CO2 into CO, with a by-production of H2, the molecular catalyst being chosen between the list with the metal chosen among: Iron, Cobalt: metal porphyrin with on